Suicide risk in relation to psychiatric hospitalization: evidence based on longitudinal registers.

BACKGROUND Persons with a history of admission to a psychiatric hospital are at high risk for suicide, but little is known about how this is influenced by factors related to psychiatric hospitalization. OBJECTIVE To explore suicide risk according to time since admission, diagnosis, length of hospital treatment, and number of prior hospitalizations. DESIGN Nested case-control design. SETTING Individual data are drawn from various Danish longitudinal registers. PARTICIPANTS All 13 681 male and 7488 female suicides committed in Denmark from January 1, 1981, to December 31, 1997, and 423 128 population control subjects matched for sex, age, and calendar time of suicide. Main Outcome Measure Risk of suicide is estimated by conditional logistic regression. Data are adjusted for socioeconomic factors. RESULTS This study demonstrates that there are 2 sharp peaks of risk for suicide around psychiatric hospitalization, one in the first week after admission and another in the first week after discharge; suicide risk is significantly higher in patients who received less than the median duration of hospital treatment; affective disorders have the strongest impact on suicide risk in terms of its effect size and population attributable risk; and suicide risk associated with affective and schizophrenia spectrum disorders declines quickly after treatment and recovery, while the risk associated with substance abuse disorders declines relatively slower. This study also indicates that an admission history increases suicide risk relatively more in women than in men; and suicide risk is substantial for substance disorders and for multiple admissions in women but not in men. CONCLUSIONS Suicide risk peaks in periods immediately after admission and discharge. The risk is particularly high in persons with affective disorders and in persons with short hospital treatment. These findings should lead to systematic evaluation of suicide risk among inpatients before discharge and corresponding outpatient treatment, and family support should be initiated immediately after the discharge.