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

To compare the suicide attempts rate among DDP and non-DDP; To compare the suicide attempts rate according to gender in DDP and non-DDP; To compare the suicide attempts rate according to substance in DDP.

Analysis of consecutive admissions: men and women ages 18–65 in our center (06/2003–06/2005).

Of 848 DDPs' admissions, 197 (23.2%) were after suicide attempt, whereas 403 of 2558 non-DDP's admissions (15.8%) were after suicide attempt (OR=1.6; 95%CI=1.3-1.9). The OR in multiple analysis was 1.4 (95%CI=1.1-1.8).

There is higher risk for suicide attempt among females in non-DDP (OR=.6; 95%CI=.5-.8), no differences according to gender in DDP (OR=.7; 95%CI=.5-1.1).

Opiates (OR=1.6; 95% CI=1.01-2.5) and Cocaine (OR=1.9; 95% CI=1.1-3.2) were found to elevates, but Cannabis were found to lower (OR=.4; 95% CI=.3-.6) the risk of suicide attempt.

DDP have grater risk for suicide attempt than non-DDP. In non-DDPs females have grater risk for suicide attempt than males, however in DDPs there were no differences. DDP with Opiates or Cocaine abuse are in risk group for suicide attempts. These findings suggesting that preventive efforts that have shown promise in non-DDP may need to be tailored differently to address the risk factor profile of DDP.