Relationships Between Executive Functions, Metacognition and Emotional Regulation: A Study with Adults with and without Depression

Studies with Transcranial Electrical Stimulation have shown that there is a reduction in depressive symptoms, but it is still unclear whether this type of intervention can also improve cognitive functions and emotional regulation strategies in major depression. This study examined the effects of transcranial direct current stimulation (tDCS) on the dorsolateral prefrontal cortex (DLPFC) on executive functions, metacognition of thoughts and feelings, and emotion regulation. Eighteen adults between 18 and 40 years of age diagnosed with major depression were randomly assigned to active stimulation (N = 10) or sham (N = 8). Participants underwent 10 sessions of active or simulated tDCS over two weeks. Participants' depression symptom severity, executive functions, metacognition, and emotion regulation strategies were assessed at baseline, immediately after the intervention, and 3 months after the intervention. It was possible to observe that active tDCS did not have a greater effect on the variables compared to the SHAM intervention. Both groups increased the frequency of regulation of thoughts and feelings over time and decreased depressive symptoms after the intervention. The interaction between time and group was not significant in relation to emotional regulation, as well as there was no significant effect of independent variables on executive functions. The non-significant effects of tDCS on the evaluated variables are discussed in the light of previous studies, which have mixed results, corroborating and contrasting with the findings found here.