Ritmo biológico e transtornos de humor: uma perspectiva comportamental

Abstract

In the last decades, many studies have sought to understand the etiology of mood disorders and the mechanisms involved in relapses, beyond the investigation of low cost and effectiveness treatments. In this sense, the hypothesis of instability in biological rhythms has been studied as a contributing factor in the pathophysiology of mood disorders. This thesis aims to evaluate the effect of cognitive therapy on biological rhythm in a randomized clinical trial, as well as, to evaluate differences in biological rhythms in a populational-based study of individuals with the major depressive disorder, bipolar disorder, and healthy control. In addition, aims to assess correlations between the reduction of depression and anxiety symptoms and the regulation of biological rhythm were observed. Finally, aims to test the association between disruptions of biological rhythms and circadian preferences. The thesis is composed of two different study designs. The first is a randomized clinical trial with young adults aged between 18 and 29 year and aims to observe the impact of two models of brief cognitive psychotherapies for depression: Cognitive behavior therapy and cognitive Narrative therapy. The diagnosis was confirmed using the Structured Clinical Interview for DSM-IV (SCID). The biological rhythm was assessed with the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN). The severity of depressive and anxious symptoms was assessed by the Hamilton Depression Rating Scale (HDRS) and the Hamilton Anxiety Rating Scale (HARS), respectively. The second study is a cross-sectional study corresponding to the second phase of a population-based study with young adults aged from 22 to 30 years. The diagnosis was confirmed using the Mini International Neuropsychiatric Interview – (MINI)-PLUS. The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) and depression symptoms was evaluated using the Montgomery-Asberg Depression Rating Scale (MADRS). In the first study, it was possible to observe a significant reduction in 10 depressive and anxious symptoms (p<0.001) and an increase in the regulation of biological rhythm (p<0.05) at the twelve-month follow-up. Moreover, we showed a positive correlation between the reduction of depressive symptoms and regulation of biological rhythm (r=0.638; p<0.001) and between the reduction of anxious symptoms and regulation of biological rhythm (r=0.438; p<0.001). In the second study, after all adjustments, bipolar disorders and depression subjects presented higher rates of disruption in biological rhythms compared to healthy controls. Euthymic subjects showed higher biological rhythm disruption when compared to controls. Higher disruption in biological rhythms was observed in subjects with evening preferences. The findings conclude that brief psychotherapy might be effective on the regulation of biological rhythm through the remission of depression and anxiety symptoms. Moreover, we conclude that subjects with mood disorder showed higher disruption in biological rhythms as compared to controls. In subjects with bipolar disorders disruption in biological rhythms are present even in the euthymic period. Thus, monitoring biological rhythms, such as sleep, eating pattern, time of activities and social pattern can be important during the euthymic period of the disease. New treatments that target biological rhythms should be developed to allow for a more timely application of interventions and may be clinically relevant for a better prognosis of individuals with mood disorders.