Effectiveness of transcranial direct current stimulation on emotional instability and impulsivity in atypical depression and bipolar II disorder

Atypical depressive disorder and bipolar disorder often present with symptoms like emotional instability and impulsive behaviors. Various treatments, both pharmaceutical and non-pharmacological, are employed to manage these conditions. Transcranial direct current stimulation (tDCS) is a modern treatment option that has shown promise with minimal side effects. This study aims to compare the effectiveness of tDCS on emotional instability and impulsivity in individuals with atypical depression and bipolar type II. This study utilized a semi-experimental, pre-test-post-test design with a control group. The participants were patients diagnosed with atypical and bipolar depression, all of whom were referred from the neuropsychiatric clinic at Sina Hospital in Hamedan, Iran. Two hundred instability and impulsivity questionnaires were distributed among the patients using a purposeful sampling method. From these, participants were randomly assigned into four groups of 20 individuals each. The research tools included transcranial direct current stimulation (tDCS), delivered in ten consecutive sessions (30 min each, 2 mA) with the anode at F3 and the cathode at F4; the sham condition used the same montage with current discontinued after 30 s to ensure blinding., the Eysenck Personality Questionnaire (EPQ) by Eysenck and Sybil, and Barratt Impulsiveness Scale (BIS). Data analysis using covariance and multivariate covariance analysis (MANCOVA) revealed a significant difference in emotional instability and impulsivity scores between the experimental and control groups for individuals with atypical depression and bipolar type II. Direct current electrical brain stimulation was found to reduce emotional instability in these groups, leading to improved emotional stability and reduced impulsivity in people with atypical depression and bipolar disorder. The results of this study confirm the potential of direct current electrical brain stimulation in reducing emotional instability and impulsivity in individuals with atypical depression. The emergence of tDCS as a promising non-pharmacological treatment option for managing these symptoms in people with both atypical depression and bipolar disorder type II is reassuring. This method modulates the prefrontal cortex's activity, a brain region crucial for planning, decision-making, and emotional regulation. The significant potential of tDCS as a non-pharmacological intervention for atypical depression and bipolar disorder type II is a positive sign for the future. However, further research is necessary to fully realize its benefits.