Psychological Disturbances

Compiled by Ernest S Campbell, MD

Introduction
Depression
Anxiety, Phobias and Panic Attacks
Narcolepsy
Schizophrenia
Marijuana
Alcohol

Little work has been done to factualize the relationship between mental conditions and scuba diving. Other than the obvious proscriptions against someone diving who is out of touch with reality, severely depressed and suicidal or paranoid with delusions and hallucinations---one has to consider the many who can dive with everyday anxieties, fears and neuroses.

Successful divers have a profile that is positively correlated to intelligence, is characterized by a level of neuroticism that is average or below average, and score well on studies of self-sufficiency and emotional stability.

There are some actual psychological disturbances that are well known to all but are poorly documented. These include the phobic states, over-reactive anxiety states, illusions and responses to physiological abnormalities.

The normal anxiety induced by the undersea environment is complicated by an overawareness of the potential but definite dangers, causing a phobic anxiety state in susceptible people. A vicious circle results and the diver may then develop an actual phobia to descent into the water. Some "dragooned" divers experience this while learning to dive but other stronger motivating factors temporarily override their fear.

Some divers have true claustrophobia, preventing their immersion into water or even into a recompression chamber. This syndrome may only surface during certain times of stress and diminished visibility, such as in murky water, night diving or during prolonged diving.

An agoraphobic reaction - often called "blue orb or dome syndrome", it also is seen when a diver loses contact with the bottom and the surface and becomes spatially disoriented.

An over-reactive anxiety state usually occurs in response to some inadvertent mishap, such as a mask flooding with water-causing the diver to panic unnecessarily and behave irrationally. Most often this results in emergency ascents with the attendant dangers, frantic grabs for air supplies, and lack of concern for the safety of others. This is seen more often in those divers who have an above normal neuroticism gradient.

Reference

Morgan WP Anxiety and panic in recreational scuba divers. Sports Med 20 (6): 398-421 (Dec 1995) .

Scuba diving is a high-risk sport; it is estimated that 3 to 9 deaths per 100,000 divers occur annually in the US alone, in addition to increasing numbers of cases of decompression illness each year. However, there has been a tendency within the diving community to de-emphasise the risks associated with scuba diving. While there are numerous factors responsible for the injuries and fatalities occurring in this sport, there is general consensus that many of these cases are caused by panic. There is also evidence that individuals who are characterised by elevated levels of trait anxiety are more likely to have greater state anxiety responses when exposed to a stressor, and hence, this sub-group of the diving population is at an increased level of risk.

Fears associated with this environment can cause heightened suggestibility and result in mistaking fish, other divers and objects for sharks.

Finally, every diver has his own personality structure which may respond differently to abnormal physiological states and the environment. Such states include inert gas narcosis, carbon dioxide toxicity, oxygen toxicity, HPNS, etc. Each of these can cause reactions that vary in intensity from a psychoneurotic reaction to on of the organic cerebral syndromes.

Depression

The depressed diver is suffering from a mood disorder which may swing from elation to the deepest abyss of sadness. Most depressed people also have a lot of anger and anxiety underlying their mood swings. Certifying or allowing a depressed diver to continue to dive carries with it significant dangers to the diver and to his buddy. There appear to be some recorded scuba fatalities that were suicides - apparently decided upon at the moment.

Any mood condition that clouds a diver's ability to make decisions in the underwater environment is clearly dangerous and should not be allowed. Mood altering drugs used to treat depression are clearly potent and must be used with caution when diving, paying particular attention to the warnings about use in hazardous situations. Rarely do we know the pharmacological changes that take place from the physiological effects of diving on the effects of the drug. Also, discontinuance of the drug in order to dive, even for a short period of time, may be unwise.

Psychological Issues in Diving
(As published in DAN's 'Alert Diver', Sept-Dec, 2000)

Introduction

Little research has been done to factualize the relationship between mental conditions and scuba diving. Other than the obvious proscriptions against someone diving that is out of touch with reality, severely depressed and suicidal or paranoid with delusions and hallucinations---one has to consider the many who can dive with everyday anxieties, fears and neuroses.

There are some actual psychological disturbances that are well known to all but which are poorly studied and documented as concerns the risks of scuba diving. These include the depressions, bipolar disorder, anxiety and phobic states, panic disorders, narcolepsy and schizophrenia.

In addition to the risks caused by the condition itself, one must add the possible hazards of effects and side effects of medications - either as taken singly or even more dangerous, in combination. Needless to say, there have been and probably will not be good scientific studies that will indicate the safety or danger of any given set of conditions and drugs. The role of medication in diving is usually less important than the condition for which the medication is being used. A mood-altering medication is plainly powerful and should be used with care in diving. Drugs that carry warnings as dangerous for use while driving or using hazardous equipment should also be thought of as dangerous for divers. The interaction between the physiological effects of diving and the pharmacological effects of medications is usually an educated supposition. Each situation will have to be carefully evaluated individually, and there is no general rule that applies to all.

Finally, every diver has his own personality makeup, which may respond differently to abnormal physiological states and changes in the environment from the effects of various gases under pressure. Such states as inert gas narcosis, carbon dioxide toxicity, oxygen toxicity, HPNS, deep water blackout all can cause reactions that are similar to a psychoneurotic reaction or one of the organic cerebral syndromes. Therefore the diver, the dive instructor and the certifying physician all must be aware of the all the possibilities and protean manifestations of each and every individual case before allowing or disallowing diving with psychological problems.

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Depressive Disorders (Depression and Manic Depression) (Bipolar disorder)

Overview of Depressive Illnesses and Its Symptoms

Depressive and manic depressive illnesses are the two major types of depressive illness, also known as affective disorders, or mood disorders, because they primarily affect a person's mood. Different terms, respectively, include unipolar and bipolar disorder. In this section, we will predominately discuss major depressive disorder and manic depression, which encompasses symptoms of depression and mania or hypomania, a more moderate syndrome than full-blown mania.

It is estimated that over 17.4 million adults in the U.S. suffer from an affective disorder each year--that's one out of every seven people. If you've never been depressed, chances are that at some point in your life, you will become affected. Women are twice as likely as men to experience major depression while manic depression occurs equally among the sexes. The highest percentage of these illnesses occur between the ages of 25 and 44.

Where do these illnesses come from? Genetic, biochemical and environmental factors can each play a role in onset and progression. While we all experience occasional highs and lows, depressive disorders are characterized by their extremes in intensity and duration. People with severe, untreated depression have a suicide rate as high as 15 percent. In fact, the number one cause of suicide in the U.S. is untreated depression. Even so, of all psychiatric illnesses, affective disorders are among the most responsive to treatment. If given proper care, approximately 80 percent of patients with major depression demonstrate significant improvement and lead productive lives. Although the treatment success rate is not as high for bipolar disorder, a substantial number experience a return to a higher quality of life.

The Cause of Affective Disorders

Research shows that some people may have a genetic predisposition to affective disorders. If someone in your family has had such an illness, that does not necessarily mean you will develop it, nor does it explain conclusively why you did. It does increase your chances of experiencing depression of an endogenous nature (biological in basis). This is commonly referred to as clinical depression to distinguish it from short-term states of depressed mood or unhappiness. Even if you don't have a genetic predisposition, your body chemistry can trigger the onset of a depressive disorder, due to the presence of another illness, altered health habits, substance abuse, or hormonal fluctuations.

Depression can also be triggered by distressing life events, resulting in reactive depression. Losses and repeated disillusionment, from death to disappointment in love, can cause anyone to feel depressed especially if they have not developed effective coping skills. If these symptoms persist for more than two weeks, maintaining or increasing in intensity, this reactive depression may actually have evolved into a clinical depression.

Regardless of its cause, the presence of depressive or manic-depressive illness indicates an imbalance in the brain chemicals called neurotransmitters. In other words, the brain's electrical mood-regulating system is not working as it should.

An episode of depression can usually by treated successfully with psychotherapy or antidepressant medication, or a combination of both. The choice depends on the exact nature of the illness. With treatment, up to 80% of depressed people show improvement, usually in a matter of weeks.

Most depressed people also have a lot of anger and anxiety underlying their mood swings. Certifying or allowing a depressed diver to continue to dive carries with it significant dangers to the diver and to his buddy. It is possible that there are some scuba fatalities that were suicides - apparently decided upon at the moment.

Here are some of the symptoms of depression:

    Prolonged sadness or unexplained crying spells
    Significant changes in appetite and sleep patterns
    Irritability, anger, worry, agitation, anxiety
    Pessimism, indifference
    Loss of energy, persistent lethargy
    Feelings of guilt, worthlessness
    Inability to concentrate, indecisiveness
    Inability to take pleasure in former interests, social withdrawal
    Unexplained aches and pains
    Recurring thoughts of death or suicide

Symptoms of Mania (Bipolar disorder)

    Heightened mood, exaggerated optimism and self confidence
    Decreased need for sleep without experiencing fatigue
    Grandiose delusions, inflated sense of self-importance
    Excessive irritability, aggressive behavior
    Increased physical and mental activity
    Racing speech, flight of ideas, impulsiveness
    Poor judgment, easily distracted
    Reckless behavior (spending sprees, rash business decisions, erratic driving, sexual indiscretions)
    In the most severe cases, hallucinations

Divers experiencing four or more of the above symptoms of either or both depression or mania
should seek professional help if symptoms persist for longer than two weeks. Diving should be curtailed until the problem is appropriately managed. Divemasters and instructors should learn to recognize any changes in their divers' appearances, reactions and personalities and be quick to note any of the above signs and symptoms. Medical professionals also need to be aware of the dangers of diving to individuals who have conditions or are on medications that might alter consciousness or cause alteration in decision making ability in the underwater environment.
Advice About Diving
Whether or not a person with depression should be certified as 'fit to dive' should be decided on the merits of each case, the type of drugs required, the response to medication, and the length of time free of depressive or manic problems. Most probably could be allowed to dive, particularly those who have responded well to medications over a long term. Decision-making ability, responsibility to other divers and relationship to drug induced side effects that would limit ability to gear up and move in the water should be taken into consideration. Prospective divers should in all cases provide full disclosure of their condition and medications to the dive instructor and certifying agency - bearing in mind the safety of buddies, dive instructors, divemasters and other individuals who are always affected by diving incidents.

Medications used to treat depression and bipolar disorders
Buprenorphine/Buprenex
Buprenorphine has been used to treat depression that has not responded to usual medication regimens.
Side Effects Adverse to divers:
· Drowsiness: A few patients may feel tired from buprenorphine.
· Low Blood Pressure: Avoid standing from a sitting or lying position quickly.
· Headache
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Buproprion/Wellbutrin/Zyban
Buproprion is used to treat depression, attention deficit disorder, bipolar disorders, and smoking cessation.
Side effect that is adverse to diving:
Increased incidence of seizure activity, dose-related.
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Buspirone / Buspar
Buspirone is used to treat anxiety or depressive symptoms, aggressiveness, irritability, or agitation, and may be used to augment the effectiveness of an antidepressant or treat certain antidepressant-induced side effects.
Side Effects that may be adverse to diving;
Drowsiness: Occurs rarely. Make sure you know how you react to this medicine before driving or using dangerous machinery. Dizziness: This is uncommon, but may occur especially 30-60 minutes after taking a dose, with walking or standing.
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Carbamazepine / Tegretol
This medication can be used to prevent or reduce the severity of mood swings. It is also helpful in preventing the recurrence of depression.
Side Effects that may be adverse to diving.
Drowsiness: This is usually only a problem the first few weeks you are on Carbamazepine. If this is a problem, be very cautious while driving or working with dangerous machinery.
Dizziness: This is usually temporary and will go away with continued use. You may avoid this by rising or changing positions slowly.
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Lamotrigine
Lamotrigine belongs to a group of medications called anticonvulsants. Anticonvulsants are used to control seizure disorders. In psychiatry lamotrigine may also be used to stabilize mood, especially in Bipolar Affective Disorders.
Possible side effects adverse to diving include:
· Dizziness or drowsiness: Know how you react to this medicine before driving or operating dangerous machinery.
Other possible side effects include:
· Balance problems, dizziness, headache, blurred vision, tremor, nausea.
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Lithium (Lithonate, Eskalith, Lithobid, Lithane)
This medication has several uses. When taken regularly, Lithium helps prevent or reduce the severity of mood swings. Lithium can also be used to augment the effectiveness of an antidepressant.
Side effects adverse to diving may occur:
· Muscular weakness: This usually goes away with continued use.
· Drowsiness: This usually goes away with time. If you are drowsy, use caution with driving or operating dangerous machinery. .
Too much Lithium can cause toxicity.
· Nausea and vomiting, diarrhea, tremor, dizziness, sleepiness, slurred speech, balance problems.
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Monoamine-Oxidase Inhibitors:
Nardil/Phenelzine and Parnate/Tranylcypromine
MAOI’s are used to treat depression and anxiety disorders.
This medication is usually very well tolerated. However possible side effects include:
· Dizziness: This may be due to low blood pressure. Dizziness may occur when you get up quickly or rapidly change positions. Arise or change positions slowly. This tends to occur only the first 2 months of treatment or with dosage increases. Taking all the dose at bedtime, or taking several smaller doses during the day may be helpful. Contact your physician before making any dosage changes.
· Drowsiness: This is usually transient, lasting up to several months.
· Tremor: This is an uncommon side effect, which may improve with continued use of the medication.
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Methylphenidate / Ritalin
Methylphenidate is used to treat Attention Deficit Disorder, and to augment the effects of antidepressants.
Possible side effects adverse to diving include:
· Excessive stimulation: Consider decreasing the dose or waiting longer between doses.
· Nervousness: This may occur when beginning to take this medication or increasing the dose.
· Increased blood pressure: Have your blood pressure checked weekly while on this.
· Increased resting heart rate: This tends to return to normal after a couple months.
· Infrequent side effects may include: headache, abdominal discomfort, fatigue.
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Mirtazapine (Remeron)
Mirtazapine is used to treat depressive and anxiety symptoms.
Possible side effects adverse to diving include:
· Drowsiness: Mirtazapine should be taken one hour before bedtime. Make sure you know how you react to this drug before driving or using dangerous machinery. Drowsiness often disappears with increased dose.
· Dizziness: Arise from sitting or lying position slowly. .
· Dry Mouth: Drink plenty of fluids. Chew sugarless gum or suck on sugarless candy to promote saliva production.
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Venlafaxine / Effexor
Venlafaxine is used to treat depressive symptoms and attention deficit hyperactivity disorder.
Possible side effects adverse to diving include:
· Anxiety/restlessness: This may diminish with continued use.
· Drowsiness: Make sure you know how you react to this medicine before driving or using dangerous machinery.
· Dry Mouth: This may diminish with continued use. Dry mouth may increase your risk for dental disease. Chew sugarless gum and brush at least daily with fluoridated toothpaste.
· Rare side effects include: Seizure, fainting, muscle tightness, menstrual changes, excitability, trouble breathing, swelling of feet or legs.
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S-Adenosyl-L-Methionine (SAMe)
SAMe has been cited to alleviate depression, reduce symptoms of fibromyalgia, slow progress of osteoarthritis, improve memory, reduce alcohol-induced liver damage, and possibly reduce symptoms of attention deficit hyperactivity disorder.
Possible side effects adverse to diving include:
· Dry Mouth: Drink plenty of fluids. Chew sugarless gum or suck on sugarless candy.
· Blurred vision: Unusual.
· Restlessness, anxiety, &/or elation
· Patients with bipolar depression may switch to a manic state. .
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Sertraline / Zoloft
Sertraline is used to treat depression, anxiety, and obsessive-compulsive symptoms.
Possible side effects adverse to diving include include:
· Anxiety/restlessness: This will usually diminish with continued use.
· Drowsiness: If this occurs, take this medication 1 hour before bedtime. This usually diminishes with continued use.
· Dry mouth: This may diminish with continued use. Dry mouth may increase your risk for dental disease. Chew sugarless gum and brush at least daily with fluoridated toothpaste.
· Tremor: This tends to diminish with continued use.
· Bruising/bleeding: Use of sertraline can slightly increase risk of bruising and bleeding, but this can be significant when aspirin or non-steroidal anti-inflammatory drugs (e.g naproxen, ibuprofen, ketoprofen, flurbiprofen, diclofenac, sulfasalazine, sulindac, oxaprozin, salsalate, piroxicam, indomethacin, etodolac) are also taken. Barotrauma is a hazard.

St. John's Wort
St.John's wort is used to treat mild to moderate depression and possibly anxiety. This medication is not recommended for treatment of severe depression, including depression with suicidal thoughts, psychotic features (hallucinations, confused thoughts), or melancholia (weight loss, early morning awakening, very low energy).
Possible side effects include:
· Anxiety/restlessness: This will usually go away with continued use.
· Fatigue: This is uncommon and usually goes away with continued use.
· Concentration: Some studies demonstrate improved concentration and attention.
· Dizziness: This is uncommon and usually goes away with continued use.
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Tricylic Antidepressants
Tricyclic antidepressants are used to treat depression, anxiety, and chronic pain.
Possible side effects inimical to diving include:
· Drowsiness: This is usually a problem only during the first few days of starting or increasing the dose. Be cautious with driving and operating dangerous machinery until this symptom clears up. If this occurs, take this medication 1 hour before bedtime. This usually goes away with continued use.
· Dizziness: This may occur when you get up too quickly or rapidly change positions. Avoid this by changing positions slowly, especially during the night.
· Dry Mouth: This may disappear with continued use. Dry mouth may increase risk of dental disease. Chew sugarless gum, suck on sugarless candy, drink plenty of water, and brush at least daily with fluoridated toothpaste.
· Blurred Vision: This is usually temporary, rarely serious, and diminishes with continued use. Contact your physician if severe. .
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Topiramate / Topamax
Topiramate belongs to a group of medications called anticonvulsants. Anticonvulsants are used to control seizure disorders. In psychiatry topiramate may also be used to stabilize mood, especially in Bipolar Affective Disorders.
Possible side effects adverse to divers include:
· Dizziness/drowsiness: Usually goes away with continued use.
· Difficulty concentrating: May not appear until after the first month of taking topiramate.
· Tingling feelings of extremities: May disappear after first month of treatment.
· Double vision: May be temporary side effect.
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Trazodone / Desyrel
Trazodone is used to treat depression, some sleep problems, and agitation.
Possible side effects adverse to divers include:
· Drowsiness: Do not drive a car or operate dangerous machinery until you know how this drug affects you. Taking the evening dose 10 hours before arising the next morning may make this more tolerable.
· Dry mouth: This is usually temporary. Suck on sugarless candy or chew sugarless gum. Use fluoridated toothpaste at least twice daily.
· Dizziness: This may occur when you arise from a lying or sitting position too quickly, especially 4-6 hours after taking your medication. Rise and change positions more slowly to let your body adjust.
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Valproic Acid / Depakote
Valproic acid belongs to a group of medications called anticonvulsants. Anticonvulsants are used to control seizure disorders, but in psychiatry Valproic Acid may also be used to stabilize mood, especially in Bipolar Disorders.
Possible side effects adverse to diving include:
This medication may cause drowsiness. Know how you react to this medicine before driving or operating dangerous machinery.
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Nefazodone / Serzone
Nefazodone is used to treat depression and anxiety symptoms.
Possible side effects adverse to divers include:
· Drowsiness: Do not drive a car or operate dangerous machinery until you know how this drug affects you.
· Dry mouth: This is usually temporary. Suck on sugarless candy or chew sugarless gum. Use fluoridated toothpaste at least twice daily.
· Dizziness: This may occur when you arise from a lying or sitting position too quickly, especially 4-6 hours after taking your medication. Rise and change positions more slowly to let your body adjust.
· Low Blood Pressure: This is uncommon and may subside with continued use.
Blurred Vision: This is unusual, usually temporary, and usually subsides with continued use.

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Paroxetine / Paxil
Paroxetine is used to treat depression, anxiety, and obsessive-compulsive disorder.
Possible side effects inimical to diving include:
· Anxiety/restlessness: This will usually go away with continued use. If this causes difficulty, contact your psychiatrist.
· Drowsiness: If this occurs, take this medication 1 hour before bedtime. This usually goes away with continued use.
· Dry Mouth: This may disappear with continued use. Dry mouth may increase risk of dental disease. Chew sugarless gum and brush at least daily with fluoridated toothpaste.
· Blurred Vision: This is usually temporary and will diminish with continued use.
· Tremor: This tends to go away with continued use.
· Bruising/bleeding: Use of paroxetine can slightly increase risk of bruising and bleeding, but this can be significant when aspirin or non-steroidal anti-inflammatory drugs (e.g naproxen, ibuprofen, ketoprofen, flurbiprofen, diclofenac, sulfasalazine, sulindac, oxaprozin, salsalate, piroxicam, indomethacin, etodolac) are also taken. This might be a danger with barotrauma.

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Anxiety, Phobias and Panic Attacks

Normally, fear and anxiety can he helpful, helping us to avoid dangerous situations, making us alert and giving us the motivation to deal with problems. However, if the feelings become too strong or go for too long, they can stop us from doing the things we want to and can make our lives miserable.
Anxiety in the mind causes worried feelings, tiredness, loss of concentration, irritability and insomnia.
It affects the body by producing irregular heartbeat, sweating, tense muscles and pain, heavy rapid breathing, dizziness, faintness, indigestion and diarrhea.

These symptoms are often mistaken by anxious people for evidence of serious physical illness and their worry about this can make the symptoms even worse. Sudden unexpected surges of anxiety are called panic, and usually lead to the person having to quickly get out of whatever situation they happen to be in. Panic occurring at depth can lead to near-drowning and lung over-expansion injuries and death.

The normal anxiety induced by the undersea environment is complicated by an over-awareness of the potential but definite dangers, causing a phobic anxiety state in susceptible people. A vicious circle results and the diver may then develop an actual phobia to descent into the water. Some "dragooned" divers experience this while learning to dive but other stronger motivating factors temporarily override their fear. Anxiety is a normal human feeling. We all experience it when faced with situations we find threatening or difficult.

An over-reactive anxiety state usually occurs in response to some inadvertent mishap, such as a mask flooding with water-causing the diver to panic unnecessarily and behave irrationally. Most often this results in emergency ascents with the attendant dangers, frantic grabs for air supplies, and lack of concern for the safety of others. This is seen more often in those divers who have an above normal neuroticism gradient.

Phobias

A phobia is a fear of particular situations or things that are not dangerous and which most people do not find troublesome. A person with a phobia has intense symptoms of anxiety, as described above. But they only arise from time to time in the particular situations that frighten them. At other times they don't feel anxious. If you have a phobia of dogs, you will feel OK if there are no dogs around, if you are scared of heights, you feel OK at ground level, and if you can't face social situations, you will feel calm when there are no people around.

A phobia will lead the sufferer to avoid situations in which they know they will be anxious, but this will actually make the phobia worse as time goes on. It can also mean that the person's life becomes increasingly dominated by the precautions they have to take to avoid the situation they fear. Sufferers usually know that there is no real danger, they may feel silly about their fear but they are still unable to control it. A phobia is more likely to go away if it has started after a distressing or traumatic event.

About one in every ten people will have troublesome anxiety or phobias at some point in their lives. However, most will never ask for treatment. Some divers have true claustrophobia, preventing their immersion into water or even into a recompression chamber. This syndrome may only surface during certain times of stress and diminished visibility, such as in murky water, night diving or during prolonged diving. There is no one cure for it, but there are various treatments, such as Exposure therapy <http://www.sonic.net/~fredd/treat.html> , a behavioral technique that exposes you to the situation you fear most -- being in enclosed spaces. The two most popular forms of this therapy are 'slow desensitization' and 'flooding'. Flooding is a rapid and more intense form of desensitization without any relaxation techniques. Rather you are exposed directly to what you most fear until the anxiety subsides. Such direct exposure can be imagined or an actual confrontation with the phobic trigger. This would seem to be a dangerous method of treatment in the underwater milieu.

An agoraphobic reaction - often called "blue orb or dome syndrome <http://www.scuba-doc.com/bluorb.htm>", it also is seen when a diver loses contact with the bottom and the surface and becomes spatially disoriented.

Sensory deprivation can also cause illusions, particularly when there is impaired visibility. Anxiety associated with this environment can cause heightened suggestibility and result in mistaking fish, other divers and objects for sharks.

Panic Disorders

See also
UHMS Panic Survey Presentation, D. Colvard, MD (12,000 divers)
Power Point presentation http://scuba-doc.com/UHMSPanic1.pdf
Table of Relative Risk for Panic http://scuba-doc.com/UHMSPanic2.pdf
Incidence of Panic http://scuba-doc.com/UHMSPanic3.pdf

Recent studies are beginning to suggest that episodes of panic or near-panic may explain many recreational diving accidents and possibly throw light on the cause of some diving fatalities. There is also evidence that individuals who have a high level of underlying anxiety are more likely to have greater responses when exposed to stresses, and hence, this sub-group of the diving population is at an increased level of risk. In a recent national survey, more than half of divers reported experiencing at least one panic or near-panic episode. Panic attacks are often spurred by something that a non-diver would deem serious -- entanglement, an equipment malfunction or being startled by some unexpected sea creature. The attacks can lead to irrational and dangerous behavior. If divers and instructors knew more about the phenomenon they could screen out people who might be susceptible to life-threatening panic attacks.

The panic attacks are not restricted to beginning divers; sometimes experienced scuba divers with hundreds of logged dives experience panic for no apparent reason. It is thought that in such cases the panic occurs because divers lose sight of familiar objects, become disoriented and experience a form of sensory deprivation. This problem has been labeled the "blue orb syndrome." However, among inexperienced divers, there is usually an objective basis (e.g., loss of air or a shark) behind the panic response.

Panic response is when a diver behaves irrationally. The diver’s attention narrows and he loses the ability to sort out his options. If, for example, a problem develops with the regulator, the restricted air flow could prompt the diver to ascend rapidly enough to cause an air embolism (bubble) in the bloodstream, which can be fatal. This would be considered a panic response if the diver had other safe options, such as access to a pony bottle (an emergency air supply), or was diving with other divers who could share their air supply, allowing a gradual ascent.

There are some obvious diving activities which tend to lead to panic episodes, such as the stresses of equipment malfunctioning, dangerous marine life (e.g., sharks), loss of orientation during a cave, ice or wreck dive, and so on. Diving with faulty or inappropriate equipment or performing high-risk dives has greater potential for panic episodes; these problems can be prevented or minimized with appropriate training and cautionary actions.

There is a psychological concept known as "trait anxiety" that is regarded as a stable or enduring feature of personality, whereas state anxiety is situational or transitory. In this regard, it can be accurately predicted that individuals who score high on trait anxiety are more likely to have increased state anxiety and panic during scuba activities and are at potentially greater risk than those scoring in the normal range. These people probably should not dive because it has been found that interventions such as biofeedback, hypnosis, imagery and relaxation have not been effective in reducing the anxiety responses associated with the panic attacks. Psychological research has shown that hypnosis is effective in relaxing scuba divers, but it can also have the undesired effect of increasing heat loss in divers. Relaxation can lead to increased anxiety and panic attacks in some "high anxious" individuals (this phenomenon is known as relaxation-induced-anxiety, or RIA). Individuals with a history of high anxiety and panic episodes should probably be identified and counseled during scuba training classes about the potential risks.

Advice About Diving

Whether or not a person with anxiety, phobias and panic attacks should be certified as 'fit to dive' should be decided on the merits of each case, the type of drugs required, the response to medication, and the length of time free of anxiety and phobic problems. Identification of individuals who score high on trait anxiety are more likely to have increased state anxiety and panic during scuba activities and are at potentially greater risk than those scoring in the normal range. Most probably should not dive but if allowed to dive should be carefully monitored and fully informed of their risks.Decision-making ability, responsibility to other divers should be taken into consideration. Prospective divers should in all cases provide full disclosure of their condition and medications to the dive instructor and certifying agency - bearing in mind the safety of buddies, dive instructors, divemasters and other individuals who are always affected by diving incidents.

Medications used to treat anxiety, phobias and panic disorders
(Note: Many of the medications listed under depression are also used for anxiety.)

Benzodiazepines
Medications in this group used to treat anxiety include: Alprazolam/Xanax, Chlordiazepoxide/Librium, Clonazepam/Klonopin, Clorazepate/Tranxene, Diazepam/Valium, Halazepam/Paxipam, Lorazepam/Ativan, Oxazepam/Serax, Prazepam/Centrax.
Side Effects Adverse to diving include
· Drowsiness: This is a common side effect. Make sure you know how you react to this medicine before driving or using dangerous machinery.
· Dizziness: Be careful about standing up quickly, going up and down stairs, and driving.
· Difficulty learning: This is an unusual side effect and tends to go away quickly with continued use.
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Beta Blockers
Medications in this group used to treat anxiety include: Propanolol/Inderol, Pindolol/Visken, Atenolol/Tenormin, Acebutolol/Sectral, Betazolol/Kerlone, Bisoprolol/Ziac or Zebeta, Carteolol/Cartrol, Carvedilol/Coreg, Labetalol/Normodyne or Trandate, Metoprolol/Lopressor, Nadolol/Corgard or Corzide, Penbutolol/Levatol, Timolol/Blocadren or Timolide.
Side Effects inimical to diving include;
· Drowsiness: This is a common side effect. Make sure you know how you react to this medicine before driving or using dangerous machinery.
· Dizziness: Be careful about standing up quickly, going up and down stairs, and driving.
· Low Blood Pressure
· Slow pulse. This particularly important to divers, as they may not be able to respond to exercise and stress in case of need.
· Breathing difficulty, wheezing, cough
· Dry mouth: Drink plenty of fluids. Chew sugarless gum. Suck on sugarless candy. Pay special attention to dental hygiene (brush and floss regularly).
Patients with asthma or diabetes may develop special side effects while taking these medications.

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Celexa / Citalopram
Citalopram is used to treat depression, anxiety, and obsessive-compulsive disorder.
Possible side effects adverse to diving include: .
· Anxiety/restlessness: This will usually go away with continued use.
· Drowsiness/Dizziness: Avoid driving or working with dangerous machinery until the effect of this medication is known..
· Bruising/bleeding: Use of citalopram can slightly increase risk of bruising and bleeding, but this can be significant when aspirin or non-steroidal anti-inflammatory drugs (e.g naproxen, ibuprofen, ketoprofen, flurbiprofen, diclofenac, sulfasalazine, sulindac, oxaprozin, salsalate, piroxicam, indomethacin, etodolac) are also taken. Barotrauma to sinuses, ears and lungs may cause significant hemorrhage.
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Fluoxetine / Prozac
Fluoxetine is used to treat depression, anxiety, and obsessive-compulsive disorder.
Possible side effects adverse to diving include: .
· Anxiety/restlessness: This will usually go away with continued use.
· Tremor: This tends to go away with continued use.
· Bruising/bleeding: Use of fluoxetine can slightly increase risk of bruising and bleeding, but this can be significant when aspirin or non-steroidal anti-inflammatory drugs (e.g naproxen, ibuprofen, ketoprofen, flurbiprofen, diclofenac, sulfasalazine, sulindac, oxaprozin, salsalate, piroxicam, indomethacin, etodolac) are also taken.
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Fluvoxamine / Luvox
Fluvoxamine is used to treat depressive, anxiety, and obsessive-compulsive symptoms.
Possible side effects adverse to diving include:
· Anxiety/restlessness: This will usually diminish with continued use. If anxiety causes difficulty, consult with your physician.
· Drowsiness: If this occurs, take this medication 1 hour before bedtime. Make sure you know how you react to this medicine before you drive or use dangerous machinery. This usually diminishes with continued use.
· Tremor: This tends to diminish with continued use.
· Bruising/bleeding: Use of fluvoxamine can slightly increase risk of bruising and bleeding, but this can be significant when aspirin or non-steroidal anti-inflammatory drugs (e.g naproxen, ibuprofen, ketoprofen, flurbiprofen, diclofenac, sulfasalazine, sulindac, oxaprozin, salsalate, piroxicam, indomethacin, etodolac) are also taken. Bleeding with barotrauma would be a concern.

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Narcolepsy

Narcolepsy is a chronic disorder affecting the brain where regulation of sleep and wakefulness take place. Narcolepsy can be thought of as an intrusion of dreaming sleep (REM) into the waking state.
The question of the narcoleptic becoming certified for scuba diving is posed periodically - usually followed by a barrage of letters and postings to bulletin boards writing about the unknown dangers of this illness. Of course, no scientific studies have been done on narcoleptics diving and all that is written is pure supposition, based on knowledge of the condition and knowledge of what can happen to the diver with decreased awareness or consciousness.

Some people, no matter how much they sleep, continue to experience an irresistible need to sleep. People with narcolepsy can fall asleep while at work, talking, and driving a car for example. These "sleep attacks" can last from 30 seconds to more than 30 minutes. They may also experience periods of cataplexy (loss of muscle tone) ranging from a slight buckling at the knees to a complete, "rag doll" limpness throughout the body.

The prevalence of narcolepsy has been calculated at about 0.03% of the general population, or, about one person in 2000. Its onset can occur at any time throughout life, but its peek onset is during the teen years. Narcolepsy has been found to be hereditary along with some environmental factors. Narcolepsy is a very disabling and under-diagnosed illness: the effect of narcolepsy on its victims is devastating.

Studies have shown that even treated narcoleptic patients are often markedly psychosocially impaired in the area of work, leisure, interpersonal relations, and are more prone to accidents. These effects are even more severe than the well-documented deleterious effects of epilepsy when similar criteria are used for comparison.

Symptoms include excessive sleepiness, temporary decrease or loss of muscle control (sometimes associated with getting excited), vivid dreamlike images when drifting off to sleep and waking up unable to move or talk for a period of time.

Narcolepsy and Driving
There are several states that have imposed driving restrictions upon people with narcolepsy. These restrictions usually entail a narcolepsy-free period of one year after starting treatment; and, no drug-related symptoms. It might appear that these same restrictions would apply to scuba diving.
Another aspect of this condition concerns the side effects from the drugs used to combat the sleepiness. Medications used to treat narcolepsy include stimulants, anti-cataleptic compounds and hypnotic compounds, some of which have definite effects and side effects that are inimical to diving. Stimulants that increase the metabolic rate can cause an increased risk of oxygen toxicity in nitrox divers. Any of the drugs that alter the sensorium also alter the decision-making process or increase risk-taking and are definitely adverse to divers.

Advice About Diving

Whether or not a person with narcolepsy should be certified as 'fit to dive' should be decided on the merits of each case, the type of drugs required, the response to medication, and the length of time free of narcoleptic problems. Relationship to excitement, emotions and stressful situations should be taken into consideration. Prospective divers should in all cases provide full disclosure to the dive instructor and certifying agency - bearing in mind the safety of buddies, dive instructors, divemasters and other individuals who are always affected by diving incidents. It might also be wise to consider the use of a full face mask to decrease the risk of drowning in case of unconsciousness during a dive.

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Schizophrenia

Schizophrenia is a serious mental illness that affects one person in a hundred. It usually develops in the late teens or early twenties, though it sometimes starts in middle age or even much later in life. The earlier it begins, the more potential it has to damage the personality and the ability to lead a normal life. Although it is treatable, relapses are common, and it may never clear up entirely. It makes working and studying, relating to other people and leading a full, independent life very difficult, and causes families much distress.

Thoughts, feelings and actions are somewhat disconnected from each other so that what a person says may be out of keeping with what they feel or do, or what they do may be out of keeping with what they say or feel. This may be easier to illustrate by describing the symptoms. These are divided into positive symptoms, which are abnormal experiences, and negative symptoms, which are more an absence of normal behaviour and disorganized symptoms, indicating the extent of disorganization of the thought processes and vocalizations of the patient.

Positive symptoms
We normally feel that we are in control of our thoughts and actions, but schizophrenia interferes with this feeling of being 'the captain of the ship'. It may feel as though thoughts are being put into the mind or taken out by some outside, uncontrollable force. At worst, the whole personality seems under the influence of an alien force or spirit. This is a terrifying experience, which the person tries to explain according to education and upbringing.

Hallucination is the experience of hearing, smelling, feeling or seeing something that is not there. Voices are the most common hallucination, and they sound so real that the hearer is convinced that they come from the outside - as if from loudspeakers or the spirit world. These voices are distressing as they talk about the person as well as to the person.

Delusions are false and usually unusual beliefs, which cannot be explained by the believer's culture or changed by argument. These ideas may be fantastic, as in - 'I'm God's messenger!' - or apparently reasonable - 'Everyone at work is against me'. Persecutory delusions are especially distressing for the family if they are seen as the persecutors. Delusions may come out of the blue or may start as an explanation for hallucinations or the sensation of being taken over.

Negative symptoms
These affect interest, energy, emotional life and everyday activities. They avoid meeting people, say little or nothing and may appear emotionally blank.

Disorganized symptoms
Schizophrenia often interferes with a person's train of thought and it becomes difficult to understand their gibberish. They will shout back at their voices or will comply with the instructions of the voices, often hurting themselves or others.

Causes of schizophrenia

The cause of this condition is unknown. However, approximately one in ten people with schizophrenia have a parent who suffers from the illness. But the gene, or combination of genes, responsible has yet to be discovered.

An episode of schizophrenia often occurs after some stressful event - and, though it cannot be the cause, it may help to bring the illness on. Long-term stress, such as family tensions, may also make it worse. Street drugs like ecstasy, LSD, amphetamines and marijuana (hash, pot, ganja) are thought to bring on schizophrenia. There is no evidence that it is brought on by disturbed families.

Before the advent of Thorazine in the 1950s, many people with schizophrenia spent most of their lives in mental hospitals. Things have changed since then and most people with the illness are treated outside hospital for most of their lives.

After a first episode of schizophrenia, about a quarter make a good recovery within five years, two thirds will have multiple episodes with some degree of disability between these episodes, and 10-15% will develop severe continuous incapacity. Although the illness is severe and disruptive, many people who suffer from it are eventually able to settle down, work and make lasting relationships.

Medications
Since 1954, a number of drugs have been available for the treatment of schizophrenia. Most work by blocking the path of a particular chemical messenger, dopamine, in the brain. The drugs usually suppress positive symptoms; delusions and hallucinations gradually go away in a few weeks. There are, however; side-effects, especially stiffness and shakiness, like Parkinson's disease (which can be reduced by giving anti-Parkinsonian drugs). Anti-schizophrenia drugs may also cause slowing up, sleepiness and putting on weight. The worse consequence is unwanted and lasting movements of the mouth and tongue - tardive dyskinesia (TD for short) - which affects a number of people who have taken anti-schizophrenia drugs for a year of more, and may not go away even if the drugs are stopped.
Fortunately new drugs are now available which block different chemical messengers and are much less likely to cause side-effects. They may also help the negative symptoms, on which the older drugs have very little effect.

Because of the risk of repeated episodes, it is usually advisable to take drugs for years, if not forever. Although the dose is less than for an acute episode, it can still cause side-effects.

Advice About Diving

Whether or not a person with schizophrenia should be certified as 'fit to dive' should be decided on the merits of each case, the type of drugs required, the response to medication, and the length of time free of schizophrenic problems. Most probably should not consider diving. However, some who have responded well to medications over a long term may be considered for diving. Decision-making ability, responsibility to other divers and relationship to drug induced side effects that would limit ability to gear up and move in the water should be taken into consideration. Prospective divers should in all cases provide full disclosure to the dive instructor and certifying agency - bearing in mind the safety of buddies, dive instructors, divemasters and other individuals who are always affected by diving incidents. Those responsible for divers should be alert to those with inappropriate responses or activity, paranoid behavior or unusual ideation and be quick to ask and find out more about the possibility of schizophrenia.

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Medications used to treat this disorder

Clozapine / Clozaril
Clozaril is used to treat nervous, mental, and emotional conditions, such as preoccupation with troublesome and recurring thoughts, and unpleasant and unusual experiences such as hearing and seeing things not normally seen or heard.
Blood tests:
· Clozapine can cause a low WBC in 1 - 2% of patients, which can cause serious problems. This usually occurs between 6-18 weeks after starting Clozapine. White Blood Cells help to fight infections. Diving could possibly increase the risks of severe vibrio infection.
Possible Side Effects adverse to diving include:
Seizure: These have occurred in 1-2% of patients taking less than 300 mg/day, 3-4% taking 300-600 mg/day, and 5% over 600 mg/day. Contact your prescriber immediately if a seizure occurs.
· Increased saliva production: Most patients will get this side effect. Some tolerance develops after 8-12 weeks. This would increase the production of swallowed air with attendant difficulty on ascent.
· Feeling tired, dizziness: Usually improves or goes away in 3-4 weeks.
· Low blood pressure with standing: Usually improves with time. Discuss increasing the dose slower with your prescriber.
· Heart beating faster: Usually does not cause serious problems. Tolerance may develop.
· Restlessness, tremors, stiffness, muscle spasms are uncommon, but can be treated.
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Quetiapine / Seroquel
Quetiapine is used to treat psychotic symptoms and disorders, such as schizophrenia.
Possible side effects include:
· Low blood pressure: Usually occurs with standing from a lying or sitting position. Arise slowly and allow your body more time to adjust the blood pressure.
· Sleepiness: Common, but usually mild and transient.
· Cataracts: One study with dogs showed a possible increase in cataract formation. This has not yet been reported in humans. You should have your eyes examined every 6 months.
· Other occasional side effects may include headache, dry mouth, dizziness, insomnia, constipation, and agitation.
Quetiapine may cause muscle stiffness, hand tremors, face and mouth movements, and rarely neuroleptic malignant syndrome (high fever, stiffness, and flu-like symptoms). These symptoms occur less often than with older typical anti-psychotic medications.
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Risperidone / Risperdol
Risperidone is used to treat nervous, mental, and emotional conditions, such as preoccupation with troublesome and recurring thoughts, and unpleasant and unusual experiences such as hearing and seeing things not normally seen or heard.
How does it work?
The effects of this medication appear to be related to reducing activity of a brain substance called dopamine. It also blocks some serotonin activity in the brain. Some of the benefits may occur in the first few days, but it is not unusual for it to take several weeks or months to see the full benefits. In contrast, many of the side effects are worse when you first start taking it.
Possible Side Effects Adverse to Divers:
· All medications that act on dopamine can sometimes have side effects involving muscle coordination or muscle tension. It appears that Risperidone is somewhat less likely to cause this type of side effect than others. Examples can include stiffness in the arms, back or neck. Sometimes patients experience shakiness or problems with muscle coordination.
Some people who take Risperidone may become more sensitive to sunlight. When you first begin taking this medicine, avoid too much sun and do not use a sunlamp until you see how you react, especially if you tend to burn easily. If you burn easily or have a severe reaction, contact your physician.

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Haloperidol
Brand name: Haldol is a butyropherone derivative with antipsychotic properties that has been considered particularly effective in the management of hyperactivity, agitation, and mania.
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New Drugs for Schizophrenia

Atypical antipsychotic drugs on the market currently include clozapine, risperidone and olanzapine. Use of these medications in selected patients who do not benefit from, or cannot tolerate, traditional agents is an important step in improving the lives of patients with schizophrenia.
Use of traditional antipsychotic medications has been limited by their substantial side effects and failure to achieve long-term control of symptoms in some cases. New "atypical" antipsychotic drugs show promise for the treatment of resistant cases of schizophrenia and improvement in patient tolerance and compliance. These medications have been more successful than traditional antipsychotic drugs in treating the negative symptoms of schizophrenia, such as social withdrawal and apathy. The atypical antipsychotic drugs produce fewer extrapyramidal side effects and no tardive dyskinesia or dystonia. However, they are associated with induction of neuroleptic malignant syndrome, and clozapine can produce fatal agranulocytosis.
Olanzapine / Zyprexa
Olanzapine is used to treat psychotic symptoms and disorders, such as schizophrenia.
Possible side effects adverse to divers include:
· Tiredness, dizziness, insomnia (trouble falling asleep), nervousness, restlessness, nausea, vomiting, constipation, dry mouth, runny or stuffy nose, increased salivation, weight loss or gain, increased heart rate, and low blood pressure with standing.
· Olanzapine may cause muscle stiffness, hand tremors, face and mouth movements, and rarely neuroleptic malignant syndrome (high fever, stiffness, and flu-like symptoms). These symptoms occur less often than with older typical anti-psychotic medications.

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Effects of Marijuana Use

· The more Marijuana is used, the shorter its effects last.
· Tolerance to the psychoactive effects develops with continued use.
· Psychological and mild physical dependence gradually occurs with regular use.
Withdrawal symptoms include:
Restlessness, insomnia, nausea, irritability, loss of appetite, sweating.
· Risk of adverse reactions is greater for persons who have had schizophrenia or other psychotic disorder, depression, dysthymia, and bipolar disorder (manic-depression).
· Tar content of marijuana is significantly greater than cigarettes, with more carcinogens.
Potentially harmful effects to divers include:
· Accidents and deaths caused by distortions in perception of time, body image, and distance.
· Impairment of recent memory, confusion, decreased concentration,
· Decreased muscle strength and balance.
· Decreased blood flow in brain.
· Impaired ability to perform complex motor tasks.
· Poor memory.
· Amotivational syndrome.
· Depression, especially in new users.
· 50% of users will have a "bad trip" - severe panic reaction with fear of dying or losing one's mind.
· Fast heart rate and lower exercise tolerance.
· Dry mouth and throat.
High doses may cause:
· Hallucinations
· Depersonalization
· Paranoia
· Agitation
· Extreme panic
Chronic use may cause:
· Bronchitis, Sinusitis, Pharyngitis, Chronic cough, Emphysema, Lung cancer.
· Poor immune system functioning; severe marine infections
· Poor motivation, depressed mental functioning.
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Alcohol and Diving

Some divers insist on drinking beer before, during and after their dives. Is there any danger in drinking alcoholic beverages and diving? The short answer is that by drinking alcohol before and during diving trips a diver severely endangers not only himself but his buddy!

Blood Alcohol Concentration (BAC)
Research has shown that there is a definite reduction in the ability of the individual to process information, particularly in tasks that require undivided attention for many hours after the blood alcohol level has reached 0.0%. This means that the risk for injury of a hungover diver is increased significantly, particularly if high BAC levels were reached during the drinking episode.
The AMA upper limit of the BAC for driving a vehicle in the US is 0.05%. Surely diving with any alcohol on board would be foolish, considering the alien environment (water) and the complex skills required to follow no deco procedures.
Alcohol Impairment
All of the following behavioral components required for safe diving are diminished when alcohol is on board or has been on board in the prior 24 hours:
· Reaction time
· Visual tracking performance
· Concentrated attention
· Ability to process information in divided attention tasks
· Perception (Judgment)
· The execution of psychomotor tasks.
The individual who has alcohol onboard may not feel impaired or even appear impaired to the observer but definitely is impaired and this is persistent for extended periods of time. The use of alcohol, even in moderate doses, clearly carries a self-destructive aspect of behavior and leads to higher probabilities for serious accidents.
Alcohol is a diuretic
In addition to these dangers is the definite danger of alcohol-produced dehydration. Dehydration is considered to be one of the prime causes of decompression illness. Alcohol in any form has a direct effect on the kidneys, causing an obligatory loss of body fluids.
If your drinking buddy is an intelligent diver, surely he will understand that this is not preaching- a cool beer is appreciated by the author-but by drinking and diving he can turn a safe sport into a nightmare for himself and his family. I'm sure that when he considers that he is also endangering his buddy that he will think twice before drinking alcohol before and while diving.

There have been recent discussions in scuba magazines, chat rooms and scuba forums that it's OK to drink beer between dives during a surface interval. Some divers insist on drinking beer before, during and after their dives. Is there any danger in drinking alcoholic beverages and diving? The short answer is that by drinking alcohol before and during diving trips a diver severely endangers not only himself but his buddy!
A study by Perrine, Mundt and Weiner found (scuba) diving performances significantly degraded at blood alcohol levels of 40 mg/dl (04%BAC). They also cite a clear increase in the risk of injury at this level which can be reached by a 180 lb. man who ingests two 12 oz. beers in 1 hour on an empty stomach. This very pertinent study once again points out that there is a diminished awareness of cues and reduced inhibitions at relatively low levels of blood alcohol. Their study used well trained divers who were being paid to do their best as their diving performances were being videotaped.
My friend, Dr. Glen Egstrom, PhD has stated the problem succinctly: He made personal review of over 150 studies on the effects of alcohol on performance has resulted in the following observations:
1. Ingestion of even small amounts of alcohol does not improve performance: to the contrary it degrades performance
2. While there are variables that can speed up or delay the onset of the effects of alcohol, they are minor issues which do not overcome the decrements to the central and peripheral nervous system.
3. Alcohol can be cleared from the blood at a predictable rate. Generally on the order of .015% BAC per hour. This does not necessarily mean that the decrements in performance have been completely eliminated in that time.
4. Alcohol is a depressant drug that slows certain body functions by depressing the entire central nervous system. Effects are noticeable after one drink.
5. The effects are mood elevation, mild euphoria, a sense of well being, slight dizziness and some impairment of judgment, self control, inhibitions and memory.
6. Increases in reaction time and decreases in coordination follow the dose/response curve quite well.
7. Alcohol is involved in 50% +/- of all accidents involving persons of drinking age.
8. The deleterious effects of alcohol on performance are consistently underestimated by persons who have been drinking alcohol.
9. Divided attention tasks are found to be affected by alcohol to a greater degree than those tasks with single focus of concentration , i.e. a task such as a headfirst dive into shallow water, with many interrelated decisions necessary to a successful dive, will be impacted to a greater degree than lifting a heavy weight.
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Naltrexone / Revia
Naltrexone is used to treat alcoholism, by diminishing craving and the effect of alcohol. It is also used to decrease impulsivity associated with self-harm behaviors.
Possible side effects inimical to diving include:
· Dizziness: This is a fairly common side effect, which often disappears with continued use.

· Less common side effects may include: headache, constipation, nervousness, fatigue, insomnia, limb or abdominal pain, weight loss.