Perceived peer smoking was associated with each class of comorbidity, while perceived weekly alcohol use by peers was only associated with the AUD class. Perceived peer smoking is an established correlate of young adult substance use disorders (Agrawal et al., 2007; Jenkins et al., 2011). We are not aware of previous reports that perceived peer smoking is associated with affective disorders comorbid with AUD. It is possible that the association with affective disorders is accounted for by comorbid AUD. Further research on the association between peer smoking and affective disorders is warranted.
