The effect of chronotypes on follow-up outcomes of patients with substance use disorder.

Substance use disorder (SUD) can have circadian characteristics and individuals with evening chronotype are more prone to addiction. In this study, the effect of chronotypes on the treatment outcomes of SUD was investigated. The study included 66 patients who were diagnosed with SUD according to DSM-5. Two clinical interviews were conducted at 6-month intervals, and remission/relapse status was evaluated at the second interview. The Structured Clinical Interview Form for DSM-IV Axis I Disorders (SCID-I), Addiction Profile Index Practitioner Form, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Pittsburg Sleep Quality Index and Morningness-Eveningness Questionnaire (MEQ) were applied to the patients. MEQ scores of relapsed patients were found to be different in terms of eveningness than those in remission (45.62 ± 8.70 versus 49.75 ± 7.60,  = 0.045). As the craving and addiction profile index total scores (addiction severity) increased, eveningness chronotype scores also increased ( = - 0.387 and  = - 0.286, respectively). The mean scores of craving and BDI were higher in relapsed patients compared to those in remission ( = 0.003 and  = 0.015, respectively). Our results suggest that patients with SUD had a lower morningness chronotype than the general population; additionally, more relapsed patients had an eveningness chronotype. Thus, chronotypes may play a role in the onset, prevention, and treatment outcome of SUD.