Rhythmicity of sleep and clinical outcomes in major depressive disorder: A CAN-BIND-1 report

Background Although there is substantial research demonstrating the effects of duration and quality of sleep on outcomes in major depressive disorder (MDD), there is little research examining whether rhythmicity of sleep can also affect outcomes in MDD. The objective of our study was to investigate the relationship between rhythmicity of sleep and clinical outcomes in MDD Methods The prospective study (N = 208) included MDD patients treated with escitalopram for 8-weeks. Rhythmicity of sleep was assessed with Biological Rhythms Interview for Assessment in Neuropsychiatry (BRIAN) at baseline and after 8-weeks. Depression was assessed with Montgomery-Asberg Depression Rating Scale (MADRS) and Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) throughout 8-weeks. Outcomes were depression severity over 8-weeks and remission of depression after 8-weeks. Mixed effect models (MMRMs) and logistic regression models were conducted Results Baseline BRIAN sleep score predicted MADRS (Adjusted B = 0.34;95%CI:0.01–0.66,p = 0.04) and QIDS-SR (Adjusted B = 0.19;95%CI:0.02–0.36,p = 0.03) scores over time in MMRMs. BRIAN falling asleep (Adjusted B = 0.44;95%CI:0.01–0.86,p = 0.04) and switching off (Adjusted B = 0.50;95%CI:0.03–0.97,p = 0.04) items predicted QIDS-SR scores over time. BRIAN sleep score predicted remission with MADRS (Adjusted OR:0.87;95%CI:0.76–0.99) and QIDS-SR (Adjusted OR:0.76;95%CI:0.64–0.90) in logistic regression models. BRIAN falling asleep item predicted remission with MADRS (Adjusted OR:0.71;95%CI:0.64–0.90) and QIDS-SR (Adjusted OR:0.62;95%CI:0.42–0.92). BRIAN switching off item predicted remission with QIDS-SR (Adjusted OR:0.62;95%CI:0.40–0.96) Limitations Did not examine for circadian rhythm sleep-wake disorders or social conditions that causes circadian disturbances (e.g., shiftwork) Conclusions A disturbed rhythmicity of sleep, particularly in the ability to switch off when resting and falling asleep, may increase the risk of poor clinical outcomes in MDD.