The neurobiology of adaptation to seasons: Relevance and correlations in bipolar disorders.

The neurobiology of adaptation to seasons: Relevance and correlations in bipolar disorders. Chronobiol Int. 2018 Jun 25;:1-19 Authors: Maruani J, Anderson G, Etain B, Lejoyeux M, Bellivier F, Geoffroy PA Abstract Bipolar disorders (BDs) are severe and common psychiatric disorders. BD pathogenesis, clinical manifestations and relapses are associated with numerous circadian rhythm abnormalities. In addition, infradian fluctuations of mood, social activity, weight and sleep patterns are very frequent in BD. Disease course with a seasonal pattern (SP) occurs in approximately 25% of depressive and 15% of manic episodes, which is coupled to a more severe disease symptomatology. The pathophysiological mechanisms of seasonal effects in BD await clarification, with likely important clinical consequences. This review aims at synthesizing available data regarding the underlying pathophysiological mechanisms of seasonality in BD patients, with implications for future research directions in the study of seasonality in BD. Three factors are suggested to play significant roles in BD with SP, namely the suprachiasmatic nuclei, as well as the melatonergic and photoperiodism systems. It is proposed that BD with SP may be considered as a complex disorder resulting from the interaction of clock gene vulnerabilities and biological clock neuroplasticity, with environmental factors, such as the response to light. Light seems to play a key role in BD with S...
Source: Chronobiology International - Category: Biology Authors: Tags: Chronobiol Int Source Type: research