Do severity levels of substance use relate to self-reported variations in psychosocial distress?

This study aimed to examine whether patients who reported different severity levels of illicit substance use and alcohol differed in contemporary psychological distress and interpersonal problems. A patient sample (n = 352) was established from 16 treatment facilities for substance use disorders in Norway and by mailed questionnaires to patients at waiting lists and individuals who had completed their treatment. The response rates were 53 and 28% for data collected at the clinics and by mailed questionnaires, respectively. The questionnaire consisted of validated measures of substance use and the psychological constructs. The results showed stronger symptom load in the group manifesting severe levels of illicit substance use. Differences in alcohol consumption also reached significance. For illicit substances these differences were stronger for symptoms related to depression, anger and somatic issues, whereas differences were more substantial in anxiety symptoms related to alcohol consumption. Differences in interpersonal problems were marginal both for illicit substance use and alcohol. The results indicate that psychological distress is more directly associated with substance use than interpersonal problems. The role of interpersonal problems for substance consumption may be of a more indirect character than the connection between psychological distress and substance use.