February 2007, Vol. XXIV, No. 2
It has long been known that persons with schizophrenia are at high risk for attempted and completed suicide. With estimates of about 5% to 15% for completed suicide1,2 and 20% to 40% for attempted suicide,3-6 the recent increase in attention to this concern is promising. Most studies have involved reviews of patient charts and reviews of psychiatric and death registries, which limits our understanding of risk factors, warning signs, and potential interventions. More recently, the assessment of suicidal behavior in patients with schizophrenia in clinical trials has added a new dimension to the research.7 Prospective longitudinal studies that directly assess baseline history of suicidal behavior and related factors will be the most informative.
Risk of completed suicide and of attempted suicide may be different. In addition, some risk factors cut across psychopathologies and some are unique to individuals with schizophrenia and schizoaffective disorder. The following is a review of the risk factors for sui-cidal behavior in patients with schizophrenia; where possible, the differentiations between those who attempt suicide and those who complete suicide will be made (Table 1).
Epidemiology and demographics
The epidemiology of suicidal behavior in patients with schizophrenia has been well documented.8,9 Like suicide in other groups, more men than women complete suicide,10 although suicide attempt rates do not differ between the sexes.6 Women with schizophrenia have higher rates of suicide relative to other women.9 In general, the period of greatest risk of suicide is early in the course of illness; therefore, patients with schizophrenia who completed suicide tended to be young and in the first 5 to 10 years of illness.9 However, unlike other groups at risk, the risk of suicide in patients with schizophrenia is elevated throughout the lifespan.9 Suicide attempts tend to be of moderate to severe lethality,6 and those who attempt suicide are likely to make multiple attempts.
In addition, factors such as unemployment,8,9 single status (unmarried),6,8,9 and living alone6 have been found more often in patients with schizophrenia who attempt and complete suicide; however, this information is minimally helpful since most people with schizophrenia are unemployed and unmarried.6 Patients with schizophrenia who attempt suicide are hospitalized almost twice as often as those who do not attempt suicide, although it is unclear whether they are hospitalized for suicidal behavior or another cause.6 Taken together, these findings indicate that efforts to reduce risk should involve increasing social supports for and a sense of productivity in patients wherever possible. Indeed, quality of life has been found to be associated with suicidal behavior.11
Previous suicidal behavior
As with most disorders, the best predictor of future behavior is past behavior. In schizophrenia, almost half of suicide completers have made a previous attempt12 and attempters typically make more than one attempt.6
When assessing risk for suicidal behavior, therefore, it is important to obtain a thorough history of past suicidal ideation and attempts, including frequency, intent, plans, persistence, and most important, factors surrounding previous suicide attempts.
There is no evidence that suicidal behavior occurs frequently in response to psychotic behavior. However, suicidal behavior frequently occurs in persons bothered by their own psychotic behavior, 6 which indicates that they are often psychotic at the time of the suicidal behavior. On the other hand, the results of a study by Siris and colleagues 13 suggest that the greatest risk of suicide is during the postpsychotic period. 13 This is typically the period following hospitalization, since most individuals still retain some level of psychotic symptoms or attenuated symptoms at discharge. The first suicide attempt typically occurs some time after the onset of psychosis. 6
The presence of command auditory hallucinations (CAH) for suicide alone cannot predict suicidal behavior, but individuals who are at risk for suicide are more likely to make an attempt when they have CAH. 14 Therefore, CAH should not be ignored.
The relationship between negative symptoms and suicidal behavior is unclear because of the major methodologic limitations of reported retrospective studies. Similarly, the relationship between positive symptoms and negative symptoms and suicidal behavior requires more research since there are significant implications for treatment and prevention. Thus, current findings highlight the need for ongoing clinical care and research as well as the aggressive treatment of psychotic symptoms.
Feelings of depression are considered an integral part of suicidal behavior. Several investigators have studied the role of depression in suicidal behavior by assessing depressed mood, hopelessness, and major depression. 15-19 Major depression is common in schizophrenia, regardless of whether it is as prominent a part of the illness, as in schizoaffective disorder. 20-22 More than half of patients with schizophrenia will experience at least one major depressive episode. 22-24
As with other risk factors for suicidal behavior, the presence of depression in and of itself does not automatically lead to suicidal behavior, but individuals vulnerable to suicidal behavior are at increased risk during depressive episodes. 22 Unfortunately, it is still not widely known that antidepressants and mood stabilizers can be used in combination with antipsychotic medications and that these combinations can be more effective than antipsychotics that are presumed to have antidepressant or mood-stabilizing properties.25-27 Thus, the identification and treatment of depression in persons with schizophrenia is essential and is likely to reduce the risk of suicidal behavior.28