NEW YORK (Reuters Health) Jan 18 - Clinical predictors of suicidal acts after major depression differ between men and women, according to study findings published in the January issue of the American Journal of Psychiatry.

"Sex differences in suicidal behavior have long been recognized," Dr. Maria A. Oquendo, of Columbia University, New York, and colleagues write. "Studies have shown that men have higher suicide rates, while women are at higher risk for suicide attempts," they note.

The researchers examined whether there are differences between men and women in clinical risk factors associated with suicidal behavior in a study involving 184 women and 130 men with major depression or bipolar disorder seeking treatment for a major depressive episode. The patients were evaluated 3 months, 1 year, and 2 years after discharge.

Cox proportional hazards regression analysis was used to test putative predictors. The team hypothesized that aggression, hostility, and history of substance misuse would increase the risk for future suicidal behavior among men, while depressive symptoms, childhood history of abuse, fewer reasons for living, and borderline personality disorder would increase the risk in depressed women.

Overall, four subjects completed suicide and 48 attempted suicide during follow-up. This represented 16.6% of the cohort. Women were more likely than men to attempt suicide in the follow-up period (hazard ratio = 1.8, p < 0.05).

For men, a previous suicide attempt, family history of suicidal acts, past drug use, cigarette smoking, borderline personality disorder, and early parental separation increased the risk of a future suicidal act by at least threefold.

For women, the risk of a future suicide attempt was six times greater among those who had made a prior attempt. Each prior attempt increased the future risk threefold. The risk of future suicidal acts for women was also increased by suicidal ideation, lethality of past attempts, hostility, subjective depressive symptoms, fewer reasons for living, comorbid borderline personality disorder, and cigarette smoking.

"When all significant predictors of suicidal acts for men identified by univariate analyses were evaluated together, cigarette smoking and family history of suicidal acts emerged as the most robust predictors of future suicidal acts, but early separation from family, borderline personality disorder, and past drug abuse were no longer predictive," Dr. Oquendo and colleagues explain.

"For women, the multivariate analyses revealed that previous attempts, suicidal ideation, and smoking had independent effects on the risk for suicidal acts," they note. "The presence of multiple suicide attempts, borderline personality disorder, greater subjective depression, fewer perceived reasons for living, and hostility were no longer significant."

The researchers conclude, this knowledge may improve suicide risk evaluation and guide future research on suicide assessment and prevention."