Involvement of fatigue in the effect of transcranial magnetic stimulation (TMS) on depression following COVID-19 and COVID-19 vaccination: a before-after study

Background: Patients recovering from COVID-19 often suffer long-term Long-COVID (e.g., depression, poor concentration, anxiety, sleep disturbances, and fatigue). Similar symptoms also rarely seem to occur after COVID-19 vaccination. There is still no effective treatment for these symptoms. We have had a clinical experience that patients presenting with psychiatric/physical symptoms due to COVID-19 or COVID-19 vaccination (defined as Long-COVID and Post-Vaccine patients) often recover after transcranial magnetic stimulation (TMS) and that TMS poorly heals depression in strongly fatigued patients. Aims: 1. Determine whether there are differences in background characteristics and symptoms between Long-COVID and Post-Vaccine patients; 2. Examine whether TMS led to an improvement in their symptoms; 3. Test the involvement of fatigue in the recovery of depression of Long-COVID and Post-Vaccine patients with TMS. Methods: We conducted a retrospective analysis using the medical records of the outpatient clinic of Tokyo TMS Clinic. Results: 1. We found no differences in initial symptoms and courses of treatment between Long-COVID and Post-Vaccine patients. 2. All psychiatric/physical symptom scores after TMS were significantly better than before. Though these results are of before-and-after studies, numerous reports have suggested that TMS effectively improves depression, insomnia, anxiety, and related neuropsychiatric symptoms, which were also primary complaints of patients in this study. We thus attributed the improvement in QIDS, PHQ9 (Both indices of depression), and GAD7 (anxiety indicator) to TMS. 3. The recovery rate of depression in Long-Covid and Post-Vaccine patients with TMS decreased with the severity of fatigue. Conclusions: This is the first report to elucidate the efficacy of TMS and the factors affecting it for psychiatric symptoms after COVID-19 and COVID-19 vaccination. Our study may lead to further validation of the effectiveness and mechanisms of TMS in patients suffering from Long-COVID and COVID-19 vaccine long-term adverse reactions.