Circadian rhythm disturbances in mood disorders: characterisation and clinical impact

Abstract

Introduction Circadian rhythms, defined as endogenous oscillations that regulate metabolism, physiology and behaviour, may be frequently disrupted in mood disorders, influencing their clinical presentation and course (Srinivasan V. et al. World J Biol Psychiatry. 2006;7(3):138-151). Objectives To characterise circadian rhythm disruptions in a population of patients with mood disorders, analysing clinical and course differences in subjects with and without clinically significant circadian rhythm alterations Methods Patients selected for this cross-sectional study were assessed with CGI-BP, HAM-D, MRS, and PANSS. Circadian rhythm disturbances were evaluated with BRIAN. Patients with clinically relevant circadian rhythm disturbances were defined as BRIAN > 36 (Mondin TC et al. J Psychiatr Res. 2017;84:98-104). Bivariate analyses were subsequently performed to compare subgroups of patients. Results In our study, 61 subjects with DD or DB were enrolled. The overall mean BRIAN test score was 40.08 ± 10.26. When comparing the BRIAN test scores, both total and subscales, between subjects with DB and DD, social rhythms were significantly more altered in subjects with DB (8.63 ± 2.90 VS 6.80 ± 2.11, p=0.034). Subjects with disruption of circadian rhythms displayed greater severity of depressive symptoms (mean total HAM-D test score 16.06±8.61 VS 8.94±5.85; p<0.003, mean CGI-BP severity of depression test score 3.14±1.68 VS 1.88±1.11; p<0.010) and with a longer duration of untreated illness (6.14±8.64 VS 2.53±6.28; p= 0.040). Conclusions Alterations in circadian rhythms should be routinely investigated in all individuals with mood disorders, especially BD, and may represent a transdiagnostic psychopathological construct that defines a more severe disease phenotype. Disclosure of Interest None Declared