The rationale for focusing on the severity of cocaine dependence is that there is a nascent research literature showing potential relationships between psychiatric or SUD comorbidity and SUD severity. MDD was associated with risky behavior and cocaine use in a community study (Wild et al.,2005). In a clinical sample, bipolar disorder co-occurred commonly with substance use disorder, with an increased likelihood of mixed and rapid cycling mania, a chronic clinical course, medical disorders including liver disease, and both suicide attempts and completed suicides (Krishnan, 2005). PTSD has been associated with suicide attempts; co-occurring mood, anxiety, and personality disorder; overall psychiatric morbidity; family and social problems; marital violence; self-reported employment problems; and the number of episodes of substance abuse treatment--in both treatment samples (Back et al., 2000; Tarrier and Sommerfield, 2003; Wasserman et al., 1997) and non-treatment samples (Parrott et al., 2003; Thevos et al., 1993). ASPD also has been shown to be related to the severity of alcohol, psychiatric, and legal problems and risky sexual behavior among cocaine-abusing research treatment recipients (Ladd and Petry, 2003) and of SUD symptoms in community samples (Goldstein et al., 2007).
