Impacto da psicoterapia cognitiva nos parâmetros de estresse oxidativo de pacientes com depressão maior

Abstract

Introduction: Cognitive psychotherapies are effective for treating mild to moderate forms of major depressive disorder (MDD). Oxidative stress might contribute to the etiology and progression of MDD. Here, we evaluate the effect of cognitive psychotherapies in symptoms remission and peripheral oxidative stress parameters modulation. Methods: The sample consisted of 49 MDD patients recruited from a larger clinical trial that accesses the effectiveness of cognitive psychotherapies, and 49 control subjects without history of psychiatric disorders recruited from a population-base study which evaluates participant’s temperament and psychiatric disorders in the city of Pelotas, Southern Brazil. Serum oxidative stress parameters were evaluated in the control group and compared to MDD group. MDD Patients enrolled in seven sessions cognitive psychotherapy had oxidative stress parameters analyzed in the baseline, post-treatment and six-month follow-up. Results: Seven sessions of cognitive psychotherapy were able to reduce depressive symptoms evaluated by the Hamilton Rating Scale for Depression (HAMD) at the post-treatment and six-month follow-up compared to baseline (p<0.001). Considering the oxidative stress parameters, MDD subjects presented higher levels of TBARS (p<0.001) and nitric oxide (NO) (p=0.004) associated with lower levels of total thiol groups (SH) (p=0.037). However, the activity of the antioxidant enzyme superoxide dismutase (SOD) was not statistically different between groups (p=0.100). Our data revealed that the cognitive psychotherapy was able to prevent peripheral oxidative damage in MDD patients, reducing the levels of TBARS (p<0.001) in the follow-up and NO (p<0.001) in the post-treatment and follow-up, while increasing the total SH content (p<0.01) in the post-treatment and follow-up. No differences were observed in SOD activity. Conclusion: Oxidative stress is involved in MDD pathology and the regulation of oxidative stress parameters might represent an important mechanism associated with the clinical improvement after cognitive psychotherapy.