Epidemiologic research on the comorbidity of psychiatric and substance use disorders in the US is greatly facilitated by the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) [5,6]. The NESARC, conducted in 2001– 2002, confirmed that substance use and psychiatric disorders remain comorbid [7,8]. NESARC features facilitating comorbidity research include: A sample size (N = 43 093) large enough to examine the co-occurrence of rare and common disorders, and detailed features of these disorders.Complete assessment of all Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) alcohol abuse and dependence criteria among drinkers, and 10 categories of illicit and prescription drugs among users of those drugs [9], ensuring complete coverage of substance-specific DSM-IV criteria and no loss of information due to potentially biasing screening procedures [10,11].A prospective follow-up re-interview study of 34 653 of the original wave 1 participants (86.7%) in 2004–2005 [12], when the axis I disorders whose lifetime and 12-month prevalence were assessed at wave 1 were re-evaluated, providing information on onset, persistence and remission in the 3-year interval.Disorder-specific assessment of a wide variety of treatments.Assessment of early and proximal risk factors.
