We next explored clinical characteristics of the three groups described above (D4-only, D5-only, andD4D5), including the prevalence of psychiatric and substance use disorders that are commonly comorbid with AUD; comorbidity is frequently associated with severity (Boschloo et al., 2011; Chen et al., 2011). Table 2 provides details on these findings. Individuals in D4D5 had an earlier age-of-onset of symptoms relative to D5-only, but did not differ significantly from D4-only. D4D5 cases reported consuming more drinks in a 24-hour period than both D4-only and D5-only. The prevalence of nearly every psychiatric and substance use disorder examined was significantly higher within D4D5 relative to those in D4-only and D5-only.
