Psychiatric Morbidity is Linked to Problem Drinking in Midlife Among Alcohol-Dependent Men: A Co-Twin Control Study

Objective:Prior research on predictors of problem drinking has been limited because of an inability to attribute an unambiguous environmental explanation to observed findings. Using a prospective co-twin control design, we examined the extent to which a history of psychiatric symptoms exerts an environmental influence on problem drinking in midlife that is unconfounded by genetic underpinnings.Method:Participants were 367 complete male twin pairs (208 monozygotic, 159 dizygotic) from the Vietnam Era Twin Registry who were assessed in midlife as part of the Family Twin Study (Mage = 51.4 years, SD = 2.8). Twin pairs who were concordant for a lifetime diagnosis of an alcohol use disorder (AUD) in 1992 were selected for participation and were reinterviewed in 2001 to measure symptoms of AUD (i.e., problem drinking) since the prior assessment (past 10 years).Results:Within-pair differences in lifetime symptom counts of several psychiatric disorders measured in 1992 (i.e., major depression, dysthymia, generali...