[Risk factors for suicide attempts in dual diagnosis patients]

Patients suffering from both psychiatric disorders and substance abuse/addiction are titled "dual diagnosis patients" (DDP). Substance abuse/addiction is associated with suicidal behavior. Although our knowledge of substance abuse/addiction and suicide behavior is increasing, we lack sufficient knowledge of suicide among DDP.

(1) To compare the rate of suicide attempts among DDP and non-DDP; (2) To determine risk factors for suicide attempts in DDP.

Analysis of 3,433 consecutive admissions: men and women aged 18-65 years in our center (06/2003-06/2005).

Of 848 DDPs' admissions, 197 (23.2%) were after suicide attempts, whereas 403 of 2558 non-DDP's admissions (15.8%) were after suicide attempts (odds ratio [OR] = 1.6; 95% confidence interval [95% CI] = 1.3 - 1.9). The OR in the multiple analysis was 1.4 [95% CI] = 1.1 - 1.8). By multivariate regression analysis, the positive result for Tetrahydrocannabinol (THC) in the urine analysis was a protective factor and a diagnosis of disorders of adult personality and behavior (according to the International Classification of Disease - 10 edition [ICD-10]) was an independent risk factor for suicide attempts.

DDP have greater risks of suicide attempts than non-DDP. A comprehensive plan of preventive interventions for multidisciplinary staff is recommended in order to reduce suicide rates in DDP.