Vergallito, A., Schiena, G., Vedani, A., Maggioni, E., Gazzotti, M., Caselli, G., Ruggiero, G. M., Sassaroli, S., Brambilla, P., & Romero Lauro, L. J. (2025). Combining transcranial direct current stimulation with psychotherapy: Evidence from clinical and subclinical populations. Brain Stimulation, 18(1), 446.
ABSTRACT
Combining cognitive or behavioral interventions with non-invasive brain stimulation techniques has shown promising yet preliminary results for improving clinical symptoms across several disorders. This study aims to investigate the possibility of augmenting the effectiveness of metacognitive therapy (MCT), a third-wave cognitive-behavioral intervention, through tDCS in patients with major depressive disorder (MDD) and individuals with high levels of anxiety (HA). The two populations share high levels of repetitive negative thinking (RNT), a dysfunctional thinking style characterized by being repetitive, difficult to control, and focused on negative content. According to MCT, RNT contributes to the emergence and maintenance of psychopathology and, therefore, represents the psychotherapy intervention target.
We ran two independent randomized sham-controlled trials, including 30 MDD patients and 42 HA. In both studies, real or sham tDCS was administered concurrently with the attention training technique, which is a core exercise of MCT. The treatment lasted 8 weeks, with MCT sessions held once per week by a psychotherapist. TDCS was delivered three times a week for the first three weeks and then once weekly. The anode was positioned over the left dorsolateral prefrontal cortex (lDLPFC), and the cathode over the contralateral supraorbital area. Self-report questionnaires measuring anxiety, depressive symptoms, and RNT features were administered before and after the treatment and at four follow-ups: two weeks, three, six, and twelve months after the end of the treatment.
Preliminary findings showed a robust and stable reduction in symptoms after the treatment, confirming MCT’s effectiveness as a transdiagnostic intervention. Moreover, in line with previous evidence, tDCS effectiveness did not emerge immediately after the intervention but at later follow-ups, reducing the experienced RNT three and six months after the end of the treatment.