Delayed effects of tDCS combined with cognitive behavioral therapy in major depression: a randomized, double-blind pilot trial

Aims: This pilot study assessed the potential psychosocial and therapeutic impacts of augmenting transcranial direct current stimulation (tDCS) with cognitive behavioral therapy (CBT) in treatment-naïve patients diagnosed with major depressive disorder (MDD). Methods: In this double-blind randomized controlled trial, 10 subjects were randomized into two groups—CBT with active tDCS (active tDCS; n = 6; M = 33.3 years; 4 females) or CBT with sham tDCS (Sham; n = 4; M = 31.2 years; 2 females). Severity of depression was measured with the Montgomery–Åsberg Depression Rating Scale (MADRS) and the Beck Depression Inventory (BDI). Participants’ secondary outcomes included life satisfaction, sleep quality, and anxiety symptoms. They were assessed at baseline, following treatment (week 6), and at 2, 4, 8, and 12-week follow-ups. Results: By week 12, the active tDCS group’s BDI scores showed greater improvement relative to the sham group. There were also significant differences between groups over time in MADRS scores. Sleep quality also improved in the active tDCS group, with many participants achieving symptom-free status—defined as BDI scores of 9 or less and supported by consistently low MADRS scores—by the end of the follow-up period. Conclusions: These preliminary data indicate that the combination of tDCS with CBT may optimize the treatment of MDD through depressive symptom relief and improved sleep, while also prolonging the benefits of treatment.
This work is supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, through national funds, and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653) and is also funded by the FCT grant PTDC/PSI-ESP/29701/2017. This work was conducted at the Psychology Research Centre—CIPsi (PSI/01662), School of Psychology, University of Minho, supported by Fundação para a Ciência e a Tecnologia (FCT; UID/01662/2020) through the Portuguese State Budget.