There is plenty of evidence concerning novel treatments for major depression, as a prevalent disorder of our era (
1). ACT, GT, and tDCS are among these interventions, which are particularly useful for amelioration of depressive symptoms (
8,
28). However, for those who receive these interventions (which are carried out separately or concurrent), the risk of depression relapse is high. To the best of our knowledge, combining the effects of different therapies in succession for the MDD was explored very rarely in related literature. The results of the present case report, with a succession of tDCS, ACT, and GT, were promising, as the triangular protocol showed remarkable improvements in both electrophysiological and clinical measurements.
From the electrophysiological perspective and based on previous results associated with alpha reduction in prefrontal areas (which was also observed in EEG assessment of our patient), at the first stage, we used tDCS to increase prefrontal activity. QEEG analysis after this period revealed remarkable changes in the electrophysiological activity of the patient, as reported in previous studies (
29,
30). In addition, dramatic changes were observed in most of the depression symptoms. Our findings are consistent with Khayyer et al. (
31) showed that non-invasive electrical stimulation of the frontal lobe decreased depression scores. This can be explained by the active role of the left frontal area, especially DLPFC, in developing depression (
32). Additionally, locations of stimulation were based on the specific and sensitive QEEG measurements used in the present study. However, applying tDCS couldn’t increase “satisfaction” (one of the BDI subscales) as intended, and that is why ACT was started for the patient. On the other hand, to induce effects beyond tDCS, which are desirable, especially to achieve therapeutic effects in clinical studies, a psychotherapy intervention was suggested.
As brain activity was changed following tDCS, we supposed it was time to work on mental reconstruction using ACT techniques. These techniques target cognitive fusion and experiential avoidance, which are prevalent among depressive people. We observed that the patient’s psychological flexibility mostly increased after receiving ACT, which consequently led to higher levels of satisfaction. This result is similar to the findings of Karlin et al. (
11), who reported that ACT was effective in improving depressed veterans. Meanwhile, the patient’s second QEEG showed a more alpha decrease in the frontal areas of the brain. A possible interpretation is that neuromodulation, along with talk therapy, seems to have set the stage for a synergistic effect of biology and psychology. In a similar vein, mindfulness, diffusion, acceptance, and other ACT exercises have influenced brain regions related to attentional control, emotional regulation, and self-awareness (
15). There are some indications that the reactivity of the emotional brain systems between the frontal executive and the limbic system might be modulated by mindfulness (
33).
It has been suggested that chronic or more severe recurrent forms of depression present a weaker response to purely psychological treatments (
18), and that in patients with severe depression, combined therapy is superior to sole psychotherapy. There is also evidence that about 50% of patients who were recovered by the end of psychotherapeutic treatment suffered a relapse within two years (
34). Given the chronic nature of depression and the high chance of relapse, GT was applied as a maintenance treatment. In line with Vittengl et al. (
35), CBT was effective in reducing relapse in depression. Accordingly, the third QEEG of the patient demonstrated more frontal activity following GT. This outcome may be explained by improving frontal functions such as social abilities, problem-solving, and impulse control. This is the third edge of the triangular protocol, which was related to social competencies.
This study is the first demonstration for therapeutic and relapse prevention of combining three methods of treatment (from brain stimulation to CBT methods) in succession for depression. Each of the treatments considers different aspects of depressive disorder, and their schedules were based on different outcomes. While future research should consider these different aspects of the disorder simultaneously, the present investigation shall be considered as only a clinical case study, rather than a robust clinical study design.
Based on the positive results of the study, it might be important for future research with larger samples to consider the proposed protocol and provide further evidence that this method may be an effective and long-lasting treatment.