Circadian rhythm disturbances in mood disorders: characterisation and clinical impact

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