The association of suicide attempts and comorbid depression and substance abuse in psychiatric consultation patients

Substance abuse has been associated with attempted suicide and suicide. Few studies have examined the prevalence and associations of combined depression and substance abuse in suicide attempters. A chart review study of 1136 adult general hospital patients referred for psychiatric consultation between 1995 and 1998 was conducted to assess this further. Among 371 cases with self-harm, 311 (84%) attempted suicide. Suicide attempters were younger and diagnosed more often with comorbid substance abuse than patients without self-harm. Depressive disorders were found in 59% and substance abuse disorders in 46%. Comorbid depression and substance abuse was the most frequent category in suicide attempters, i.e., in 37%. Self-reported suicide intent was associated with increasing age, male gender, and comorbid depression and substance abuse. The suicide rate in suicide attempters was 322 per 100,000 patient-years, and 131 per 100,000 in consultation patients without self-harm. It is concluded that comorbid depression and substance abuse is associated with attempted suicide in psychiatric consultation patients. Suicide attempters should be thoroughly assessed for substance abuse. The increased suicide rate in psychiatric consultation patients with and without suicide attempts warrants further research.