SUICIDE AND SUBSTANCE ABUSE

With 29,000 annual victims, Suicide is the eighth leading cause of death in the United States. Alcohol and illicit drugs are involved in about 50 percent of all suicide attempts. About 25 percent of completed suicides occur among alcoholics and drug abusers. Substance abuse among young adults is largely responsible for the increased suicide rates under age thirty.

The relationship between substance abuse and suicidal behavior has been more extensively studied for alcoholism than for drug abuse. To evaluate this relationship, it is helpful to understand the statistical association between Alcohol and drug abuse and suicide, to learn which substance abusers are at particular risk to attempt or commit suicide, and to appreciate how this knowledge may be used to prevent suicide.

SUBSTANCE ABUSE INCREASES SUICIDE RISK

Suicides are not random; each occurs in a particular context. The association between specific psychiatric syndromes—such as Depression or abuse of alcohol or drugs—and suicidal behavior has been studied by epidemiologists using both retrospective and prospective methods. Since interviews with suicide completers are impossible, retrospective reviews of the circumstances predating suicides have been conducted. By using interviews of relatives and others familiar with the suicide victim, together with study of medical records, suicide notes, and coroner reports, each suicide case is subjected to a "psychologic autopsy." Factors that distinguish successful suicide cases from suicide attempters and substance abusers who have never attempted suicide are compared in the hope that differences in these factors may identify those at particular risk of attempted or completed suicide. A limitation of retrospective studies is termed recall bias : informants may provide information about the suicide victim that is distorted by their attempt to explain the suicide event. Although written records and use of standardized methods to collect diagnostic information can reduce this bias, prospective studies are more reliable. Prospective studies in the general population are not feasible, because suicide is rare, occurring in only about 1 in 10,000 annually; however, about 10 percent of suicide attempters, 15 percent of depressed people, and 3 percent of alcoholics eventually commit suicide. By prospective study of such high-risk groups, additional risk factors can be identified during a follow-up period.

Although most heavy drinkers are not alcoholic, heavy drinking in young adulthood is associated with suicide in middle adulthood. A prospective study of Swedish military conscripts found that those who drank more than twenty drinks weekly had three times the death rate, prior to age forty, of light drinkers. Most of these premature deaths were due to suicide or accidents. Those who develop alcohol dependence or abuse are, together with drug abusers, at increased risk of death from accidents, liver disease, pancreatitis, respiratory disease, and other illnesses; however, suicide is among the most significant causes of death in both male and female substance abusers. U.S. and Swedish prospective studies, for example, found that alcoholism increased the risk of suicide fourfold in men and twentyfold in women.

Next to depression, alcoholism and drug abuse are the psychiatric conditions most strongly associated with suicide attempts. In the U.S. Epidemiologic Catchment Area (ECA) Study conducted in the 1980s, the risk of suicide attempts was increased forty-onefold by depression and eighteenfold by alcoholism. While Cocaine users had increased rates of suicide attempts, users of Marijuana, Sedative-Hypnotics, and Amphetamines did not.

Among completed suicides, the proportion who were alcoholics or drug abusers is large: Prior to 1980, Alcoholism accounted for about 20 to 35 percent, and drug abuse for less than 5 percent, of suicides in a variety of countries. In the San Diego Suicide Study, conducted in the early 1980s, well over 50 percent of 274 consecutive suicides had alcoholism or drug abuse or dependence. Much of the increase in young-adult suicide rates since the 1960s is attributable to alcoholism and drug abuse or dependence.

RISK FACTORS FOR SUICIDE ATTEMPTS

Alcoholics and drug abusers frequently threaten to kill themselves. Many, particularly women and young adults, actually attempt it. Among alcoholics studied in the ECA communities, 32.5 percent had attempted suicide during a period of active alcoholism. About 15 to 25 percent of alcoholics in treatment programs report having previously attempted suicide. In a group of treated opiate addicts, 17 percent had attempted suicide. This represents at least a fivefold increased frequency of suicide attempts compared to those among nonsubstance abusers.

Although only about 10 percent of substance abusers who attempt suicide will die in a subsequent attempt, most substance abusers who commit suicide have attempted suicide at least once before. Thus, a review of the risks of suicide attempts may guide the identification of those substance abusers at risk of suicidal death. The risk of attempting suicide by an alcoholic or drug abuser is increased by coexisting depression, Antisocial Personality disorder (ASP), and a history of parental alcoholism.

Even among people who do not abuse alcohol or drugs, major depression increases the risk of attempting suicide. Major depression is itself 50 percent more common among alcoholics than nonalcoholics: it was found among 5 percent of male and 19 percent of female alcoholics living in the five ECA communities. Depressive feelings (but not necessarily the syndrome of major depression) often motivate alcoholics and drug addicts to enter a treatment program. Typically 20 to 40 percent of alcoholics in such programs have had a period of major depression during their lifetime. While many people drink alcohol or use drugs such as cocaine to reduce feelings of depression, experiments show that consumption produces an initial state of euphoria, followed within a few hours by anxiety, depression, and enhanced suicide ideas. Retrospective studies have found that depressive symptoms are more common among alcoholics who have made a suicide attempt.

Several studies have found that alcoholism in a parent is associated with suicide attempts among alcoholics. In addition, antisocial personality disorder (ASP) and drug abuse, which commonly occur in genetically predisposed males who develop alcoholism early in life, are associated with suicide attempts. Many clinicians have noted the repetitive high-risk behaviors of intravenous drug addicts, who often are quite aware that they may acquire infection or die by overdose with each injection. Overdoses occur more commonly among Heroin addicts who have attempted suicide than among those who have not. Highly impulsive and aggressive alcoholics or drug abusers with ASP may be a subgroup at elevated risk of attempting suicide. Transient but intense dysphoria (feeling unwell or unhappy), though not of sufficient scope or duration to meet criteria for major depression, may nonetheless increase this group's risk of attempting suicide.

Prospective studies have found that depression, anxiety, and histories of violence and legal problems were predictive of suicide attempts in previously nonsuicidal drug addicts. Retrospective studies of alcoholics and drug addicts have found that poor social supports, occupational losses, personal losses such as divorce, and other family problems increase their risk of making a suicide attempt.

RISK FACTORS FOR COMPLETED SUICIDE

Although in the general population there is considerable overlap between those who attempt suicide and those who complete suicide, substantial differences exist between these groups. For example, women are three times more likely than men to attempt suicide, while men are three times more likely to commit suicide. Despite these differences, suicide attempters are at higher risk of completed suicide. What, then, are the risk factors for completed suicide in substance abusers?

Depression.

Depressed people, particularly men, typically kill themselves in young adulthood. Among pure alcoholics, over 90 percent of suicides occur among men. In contrast to depressives, alcoholic men typically commit suicide in their fifth and sixth decades; usually this follows about twenty years of alcoholism. Men with depression, but not those with alcoholism, continue to be at elevated suicide risk beyond age sixty. Drug abuse shortens the interval preceding suicide: in the San Diego Suicide Study, drug addicts committed suicide after an average of only nine years of heavy use. They typically did so in young adulthood. This suggests that factors other than alcoholism may shorten the suicide risk period in this group. About three of four alcoholic suicides communicate their suicidal intent prior to their deaths. Thus, middle-aged male alcoholics and young polysubstance abusers, especially those who talk of suicide, are at high risk of suicide.

Long-term Use.

Ongoing substance use makes suicide more likely. Nearly all alcoholic suicides occur among active drinkers, and alcohol consumption often immediately precedes the suicide. The abstinent alcoholic is only partly protected from suicide, however, for 3 percent of suicides among alcoholics occur among those who are abstinent. It is likely that impulsiveness and transient or syndromal depression contribute to these suicides.

Psychiatric Conditions.

Coexisting psychiatric conditions, particularly depression, play an important and perhaps crucial role in the suicide of alcoholics and drug abusers. The vast majority of suicide victims have depressive symptoms at the time of their death. Concurrent depression is the leading factor in at least 50 percent of suicides among alcoholics and drug abusers. Schizophrenia, mania, and ASP are also associated with suicide in substance abusers.

Timing.

What determines the timing of suicide among substance abusers? Substance abusers often accumulate interpersonal problems throughout their drinking or drug-use careers, but one-third of those who commit suicide sustain a major interpersonal disruption (such as separation or divorce) within the six weeks preceding their deaths. They often are unemployed, living alone, and unsupported by family and friends at the time of this final and most severe disruption. In contrast, only 3 percent of nonalcoholics with depression suffer such a loss in the period before they commit suicide. Beyond psychiatric diagnoses, the strongest indicator of suicide risk in substance abusers is such an interpersonal loss. Beyond these actual losses, anticipated losses, such as impending legal, financial, or physical demise may also increase the risk of suicide among substance abusers. Among alcoholics, those who develop serious medical problems, such as liver disease, pancreatitis, or peptic ulcers, are also at higher risk of suicide.

Summary.

Which of these risk factors is the most important, and how do they interact to affect the risk of suicide? To partly answer these questions, Murphy and colleagues studied 173 white male alcoholics, 67 of whom committed suicide. After adjusting for age, the most potent risk factor for suicide was (1) current drinking, followed by (2) major depression, (3) suicidal thoughts, (4) poor social support, (5) living alone, and (6) unemployment. All suicide cases had at least one, and 69 percent had at least four, of these six risk factors. These factors act cumulatively to increase the risk of suicide in male alcoholics significantly. Their relative roles in other groups of substance abusers have not been reported.

CLINICAL FEATURES

Substance abusers who commit suicide often see a physician or are psychiatrically hospitalized in the months prior to their deaths. Those who talk of suicide may be ambivalent about their wish to die. They may thus be amenable to clinical interventions such as detoxification, substance-abuse rehabilitation, or psychiatric hospitalization. Conversely, those who take special precautions against discovery during a prior suicide attempt are much more likely to die in a subsequent suicide attempt.

Feelings of hopelessness are common in depression. While suicide attempters who are depressed and who report hopelessness are more likely to die of suicide, hopelessness is not a particular risk for completion of suicide among alcoholics. This may occur because substance abusers are motivated to commit suicide less by persistent hopelessness and more by impulsive anger, dysphoria, or feelings of isolation or abandonment.

PREVENTION

Prediction of those who will complete suicide remains poor in individual cases, even among high-risk groups such as substance abusers. Despite their high prevalence, alcoholism and drug abuse often go unrecognized by physicians and other health-care professionals. Recognition of alcohol and drug use disorders and of risk factors such as major depression that increase the risk of suicide may assist clinicians with preventive interventions. The substance abuser with active suicide plans or a recent suicide attempt may need hospitalization, detoxification, and/or rehabilitation designed to foster abstinence from alcohol and drugs of abuse. Firearms should be removed from the homes of substance abusers with active suicide ideation, especially adolescents and young adults. Treatments designed to enhance social supports and foster abstinence from alcohol and drugs, together with those directed at resolution of major depression, often reduce the risk of suicide.

(See also: Accidents and Injuries ; Complications: Mental Disorders ; Epidemiology of Drug Abuse ; Social Costs of Alcohol and Drug Abuse )

BIBLIOGRAPHY

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Allebeck, P., & Allgulander, C. (1990). Suicide among young men: Psychiatric illness, deviant behaviour and substance abuse.

Fowler, R. C., Rich, C. L., & Young, D. (1986). San Diego suicide study, II: Substance abuse in young cases. Archives of General Psychiatry, 43, 962-965.

Hesselbrock, et al. (1988). Suicide attempts and alcoholism. Journal of the Study of Alcohol, 49, 436-442.

Moscidki, E.K.et al. (1992). Suicide attempts in the epidemiologic catchment area study. Yale Journal of Biological Medicine, 61, 259-268.

Murphy, G. E. (1992). Suicide in alcoholism. New York: Oxford University Press.

Rosen, D. H. (1976). The serious suicide attempt: Five year follow-up study of 886 patients. Journal of the American Medical Association, 235, 2105-2109.

Michael J. Bohn