Comparison of Induced and Independent Major Depressive Disorders in 2,945 Alcoholics

Objective: Depressive episodes among alcohol-dependent men and women are heterogene-ous in causation and clinical course. This study tested three hypotheses regarding the rates and clinical characteristics of two potential subtypes of these affective states: those that appear to be substance-induced mood disorders and those that are independent major depressive epi-sodes. Method: Semistructured, detailed interviews were administered to 2,945 alcohol-de-pendent subjects as part of the Collaborative Study on the Genetics of Alcoholism. With the use of a time line method for determining the type of mood disorder among probands, relatives, and comparison subjects, individuals with histories of the two types of mood disorders were compared. Results: Major depressive episodes with an onset before the development of alcohol dependence or during a subsequent long abstinence period (i.e., independent depressions) were observed in 15.2 % of the alcoholics, while 26.4 % reported at least one substance-induced depressive episode. According to a logistic regression analysis, the subjects with independent (as compared to substance-induced) major depressive episodes were more likely to be married, Caucasian, and female, to have had experience with fewer drugs and less treatment for alco-holism, to have attempted suicide, and, on the basis of personal interviews with family mem