Determinants of suicidal ideation: the role of substance use disorders

This study tested the hypothesis that the amount of psychoactive substance consumed (frequency and/or quantity), life problems resulting from this use, and a DSM-IV diagnosis of substance abuse/dependence are independent risk factors associated with increased suicidal ideation in a population of psychiatric inpatients with major depressive disorder.

891 hospitalized patients with a primary diagnosis of nonpsychotic major depressive disorder (MDD) received a standardized, psychiatrist-administered assessment battery. To examine the relationship between admission suicidality and demographic, psychiatric history, and admission variables, chi-square analyses were used for categorical data and one-way ANOVAs were used for continuous indices. Stepwise hierarchical multiple regression analyses were performed to determine the set of variables that was independently related to admission suicidality level.

There was general agreement between our findings and previous literature in regard to the association between severity of Axis I diagnosis, depressed mood, hopelessness, male gender, unemployment, involuntary treatment, and alcohol/drug problems and higher suicidal ideation. In our sample of hospitalized patients with unipolar major depressive disorder, higher current drug and/or alcohol dependency and high current use of alcohol or other substances of abuse were independently associated with higher levels of suicidal ideation.

This association with higher suicidal ideation lends support to the importance of treating patients for both alcohol/drug problems and depression in an effort to decrease their risk for future suicide. We hope that our findings will improve the care that patients with dual diagnoses receive.