Etiopathology and neurobiology of obsessive-compulsive disorder: focus on biological rhythms and chronotherapy

Abstract

Rébecca Robillard,1,2 Addo Boafo,3,4 1University of Ottawa Institute of Mental Health Research, 2School of Psychology, University of Ottawa, 3Department of Psychiatry, Children’s Hospital of Eastern Ontario, 4Department of Psychiatry, University of Ottawa Medical School, Ottawa, ON, Canada Abstract: This review examines biological rhythms in persons with obsessive–compulsive disorder (OCD) and their potential relevance to the pathophysiology and treatment of this disorder. In some cases of OCD, the expression of affective, cognitive, and behavioral symptoms may be influenced by circadian and seasonal rhythms, and this could possibly interact with other neurophysiological factors. Further work is required to characterize circadian profiles linked to OCD, but findings thus far highlighted delays in both the sleep–wake cycle and melatonin secretion, as well as reduced circadian rhythmicity of body temperature. It is proposed that these changes in behavioral and endogenous rhythms may increase one’s vulnerability to obsessive–compulsive symptoms. Accordingly, obsessive–compulsive symptoms appear to be more severe in individuals with lower circadian amplitude and often worsen in the afternoon and evening. An increasing number of studies reported encouraging outcomes following the integration of sleep and circadian-based treatments in the management of OCD. There is a need for larger controlled trials evaluating the efficacy of chronotherapies in the context of OCD. Keywords: chronobiology, circadian rhythms, sleep–wake cycle