The Effect of Dual Diagnosis of Substance Use Disorders on Circadian Rhythm and Sleep Quality in Patients with Bipolar Disorder.

Introduction: In this study, it was aimed to evaluate the effect of comorbid substance use disorders (SUD), sleep quality and circadian rhythm in patients with type 1 bipolar disorder (BD) in the euthymic period.

Method: A total of 100 patients with a diagnosis of BD were divided into two groups of 50 patients each: the group with the sole diagnosis of BD (Group 1) and the group with the secondary diagnosis of SUD (Group 2). Structured Clinical Interview for DSM-5 (R) Disorders - Clinician Version (SCID-5-CV) conducted with 100 patients in the remission period for diagnostic clarity and identification of the SUD comorbidity. Sociodemographic Data Form, Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HDRS), Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Morningness Eveningness Questionnaire (MEQ) were used.

Results: Groups were compared in terms of sleep quality and circadian rhythm characteristics; PSQI and ESS to evaluate sleep quality and daytime sleepiness; MEQ and BRIAN were used to determine chronotype and biological rhythm characteristics. Pittsburgh sleep quality index showing decreased sleep quality in group 2, ESS showing increased sleepiness and BRIAN showing biological rhythm irregularity were significantly higher (p<0.05). There was no significant difference between both groups in MEQ, which determined the chronotype preference. In addition, further comparisons were made by dividing Group 2 according to dominant substance use as alcohol, cannabis and other (amphetamine, opiate) Sleep (p=0.011) and social subscale values (p<0.001) from the BRIAN subscales of Group 1 were lower than in the cannabis group. The PSQI value of Group 1 was lower than that of Cannabis and other groups (p<0.001). In addition, the MEQ value of Group 1 was found to be lower than in the alcohol group (p=0.007). The evening chronotype was more prevalent in Group 1 and the morning chronotype was more prevalent in the patients with comorbid alcohol use disorder.

Conclusion: It was determined that dual diagnosis of SUD negatively affected sleep quality, increased daytime sleepiness and caused deterioration in circadian rhythm, and there was no significant change in chronotype preference in patients with BD. In addition, in patients accompanied by cannabis use; it was determined that there was a greater deterioration in biological rhythm and sleep quality.