Efeitos da neuromodulação por corrente contínua na ansiedade, controle inibitório e comportamento de risco em jovens universitários

Abstract

The present study aimed to investigate the effects of tDCS on anxiety in young adults, as well as its effects on inhibitory control and risk behavior. Study I consisted of a systematic review that aimed to gather evidence regarding the use of tDCS in the treatment of adults with anxiety symptoms. The review also sought to examine variations in parameters such as current intensity, electrode montage, number of sessions, and session duration, with the goal of identifying which protocols show promising results depending on the intended outcome. The research was conducted using the SCIELO, PubMed, PsychInfo, Web of Science, and Embase databases, applying eligibility criteria related to tDCS and anxiety. Out of 642 articles found, the final review included eight articles, which revealed heterogeneity among the tDCS protocols used. The importance of the left and right dorsolateral prefrontal cortex in interventions targeting anxiety symptoms was emphasized. Attentional bias was highlighted as being directly related to anxiety symptoms, supporting a transdiagnostic perspective. Study II was a pilot experimental study, triple-blind, with repeated measures, aiming to evaluate the effectiveness of tDCS on anxiety symptoms, inhibitory control, and risk behavior. Data collection was carried out using the Hamilton Anxiety Scale and the State-Trait Anxiety Inventory to assess anxiety; the Go/No-Go Task for inhibitory control; and the Balloon Analogue Risk Task for risk behavior. The sample consisted of five university students who underwent two conditions: sham tDCS > active tDCS. The tDCS protocol included five sessions of bilateral stimulation with the anodal electrode positioned on the left DLPFC and the cathodal electrode on the right DLPFC, using a 2mA current for 20 minutes. All participants underwent both conditions, separated by a one-week washout period. Descriptive analyses and the Friedman test were performed using IBM SPSS STATISTICS software, version 23. The results did not indicate significant differences between conditions over time points T0, T1, and T2, except for the experimental condition on the STAI-State and the placebo condition on the STAI-Trait. Furthermore, a reduction in mean anxiety levels was observed over time in the two instruments used in the active condition, while in the sham condition, the decrease in anxiety levels was followed by an increase at the one-week follow-up. The study hypothesis was not confirmed; however, the results suggest that tDCS may modulate anxiety symptoms, albeit subtly. The lack of significance may be attributed to the small sample size, short washout period, broad tDCS protocol, and individual variability in responsiveness to neuromodulation. Therefore, it is recommended that future studies address these limitations by exploring larger samples and appropriate effect sizes.