I wrote the article printed below for DAN's "Alert Diver," July/August 2003. It has been posted to the board on several prior occasions, including within this thread---->
http://www.scubaboard.com/showthread.php?t=30427&page=2&pp=10&highlight=depression. It addresses some of the issues of which your friend may wish to be aware:
"Depression & Diving: Part II. Making the call on recreational diving.
In the March/April 2003 issue, Alert Diver took an in depth look at the nature, classification and treatment of depression, and briefly touched upon its implications for diving. In this follow up, we focus in detail on how the signs and symptoms of the condition, and their medical management, can impact safe scuba for the recreational diver and his buddy.
About one in 20 Americans show characteristics of a depressive disorder. And, because some antidepressants are used for other conditions as well, more than one in 15 takes such a medication.
As research suggests that the prevalence of depression in active divers does not significantly differ from that found in the general population, it is critical to understand what this disorder means for affected divers and the mental health professionals who treat them. During calendar year 2002, DAN Medical Services received 125-130 inquiries regarding diving with depression, and about an equal number specifically concerning the drugs used to treat it.
In a nutshell, depression is a disorder of mood. Sufferers complain of or are described by others as being down, blue, sad or empty, and as having reduced interest in or capacity to enjoy activities they once found pleasurable. Other features include disturbed sleep, changes in appetite and weight, feelings of worthlessness, hopelessness and guilt, thoughts of doing away with oneself, lack of energy, easy fatigue, loss of libido, restlessness, irritability, and difficulty in paying attention, concentrating and making decisions. In addition, depressive episodes can alternate with manic ones. With the latter, there can be groundless or excessive feelings of well-being and happiness, racing thoughts, poor judgment, recklessness, and a tendency to be easily distracted.
Of course not every individual will have all of these, and the severity ranges from mild to requiring hospitalization. The disorder is treated both by psychotherapy and medication, and often responds best to the combination.
The decision to dive or not largely takes care of itself at either extreme of the severity spectrum. However, those cases falling in between can be vexing, especially when the disorder is to varying degrees controlled by medication.
Issues related to the disorder itself
Among common signs and symptoms, indecisiveness and poorly sustained concentration perhaps rank highest on the list of concerns. Tracking and managing variables such as one's depth, location, air supply, NDLs and buddy status requires a high level of vigilance and sound, smooth decision-making. Deep underwater is not a benign place to suffer lapses in attention and decisional sharpness.
Divers revel in those seemingly effortless dives where perfect neutral buoyancy is achieved as we ride a gentle current past expanses of colorful reef. However, the requirement for vigorous activity is often just around the corner in the form of a wicked down current or buddy in need of rescue. I would not like my energy level or resistance to fatigue, or that of my buddy, to be reduced during scuba, and this can be seen in depression
Things don't always go smoothly while diving, either above or below water. Boats can arrive late, be crowded, and have dictatorial crew. Once down, the diver can inadvertently brush up against fire coral, get snagged in fishing line, or have an inconsiderate diver spoil a special photo opportunity. If irritability, which is quite common in depression, rears its head at minor provocation you have a diver who is not in optimal control.
Consideration must also be given to suicidal thought, intent and plan. Up to 9 percent of suicides in regions with easy access to water are due to drowning, and scuba offers a ready mechanism for death, one that can look to all the world like an accident. While good statistics are not available for obvious reasons, it is known that suicide accounts for a number of scuba deaths. It has been estimated that suicide may be responsible for as much as 17 percent of the deaths of professional divers in the United Kingdom. And, although not conclusive, investigations of a number of high profile scuba deaths, such as those of an ophthalmologist from Wisconsin (in Wisconsin), a psychiatrist from Missouri (in Thailand) and a couple from Louisiana (in Australia), all prominently raised the issue of possible suicide.
Finally, some persons with depression complain of bodily discomforts that have no demonstrable physical cause, including headache and joint pain. As these also can be features of DCS, report of them post-dive could result in an inappropriate trip to the chamber.
Issued related to pharmacological treatment
Drugs are frequently used to treat depression, and this raises additional concerns. Divers taking any medication should routinely investigate reported side effects.
Commonly prescribed antidepressants include three major classes: selective serotonin reuptake inhibitors (SSRIs), tricyclics/tetracyclics/heterocyclics (TCAs/HCAs), and monoamine oxidase inhibitors (MAOIs), along with a few uniquely acting compounds.
In general, SSRIs are currently more popular than the others due to their relatively greater safety (including in overdose) and tolerability, although they do cost more. MAOIs tend to be less frequently prescribed, in part because their interaction with certain foods, beverages and medications can cause severe high blood pressure. Examples of each class can be seen in Table 1.
Table 1
Prescribed Antidepressants
SSRIs:
Celexa® (citalopram)
Luvox® (fluvoxamine)
Paxil® (paroxetine)
Prozac® (fluoxetine)
Zoloft® (sertraline)
MAOIs:
Nardil® (phenelzine)
Parnate® (tranylcypromine)
TCAs/HCAs:
Adapin®, Sinequan® (doxepin)
Aventyl®, Pamelor® (nortriptyline)
Elavil®, Endep® (amitriptyline)
Ludiomil® (maprotiline)
Norpramin®, Pertofrane® (desipramine)
Remeron® (mirtazepine)
Others:
Desyrel® (trazodone)
Effexor® (venlafaxine)
Wellbutrin®, (bupropion)
Although the risk is very low, perhaps most worrisome is that the majority of medications prescribed for the condition have been shown to be associated with seizures, most particularly the SSRIs at high doses. The almost certain lethality of a convulsion underwater requires that serious attention be paid to this finding.
A second disturbing effect is drowsiness and reduced alertness, an adverse reaction known to occur with a number of antidepressants, notably the TCAs/HCAs. The SSRIs have this problem as well. Thirteen percent of patients with major depression treated with the world's most widely prescribed antidepressant (an SSRI) reported sleepiness, while research studies have demonstrated that such drugs can lead to decreased vigilance. Their effects can hinder higher cognitive functions as well, such as ability to master complex spatial tasks and to recall information learned a short while earlier.
Obviously, these medications impact on brain chemistry at ambient atmospheric pressure. It is not unreasonable to suspect the possibly that their effects could be potentiated by increased partial pressures of nitrogen and additive with those of nitrogen narcosis.
Drowsiness, dizziness, concentration disturbance and deficits in more complex cognition are among the reasons that package inserts for antidepressants contain warnings that the drug may impair the mental and/or physical abilities required for the performance of hazardous tasks, such as operating machinery or driving a car (and scuba?). The addition of medication-induced compromises of alertness, concentration and decision-making efficiency to impairments of these functions caused by the depression itself is quite troubling given a multitask recreation like scuba.
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