The efficacy of magnetic transcranial stimulation in treating treatment-resistant or prolonged depression in a clinical sample

INTRODUCTION: Depression is a common, serious and often chronic disorder and one of the leading causes of disability worldwide. The annual prevalence of depression is 5-10%, twice as high among women as men and the lifetime prevalence is at least 20%. Up to a third of depressed individuals meet criteria for treatment-resistant depression, where two antidepressants have been tried for at least 6 weeks each at therapeutic doses. As of January 2022 transcranial magnetic stimulation for adults with treatment-resistant depression that has not responded to other forms of treatment has been available by a service that is part of Primary Health Care of the Capital Area in Iceland. METHODS: This is a retrospective cohort study where participants completed a course of magnetic transcranial treatment for depression in the years 2022 and 2023. Two validated self-rating measures were used to assess depression. Information on previous treatment approaches for depression was collected from electronic health records. RESULTS: 104 individuals completed the treatment in these first two years, 60,6% women. Most had unipolar depression (86,5%), but a small subgroup had bipolar depression (13,5%). The proportion of responders varied according to the measures used, 36,1% and 45,7%, respectively, and the same was true for remission where the proportions were 12,4% and 31,5%, respectively, higher for the longer inventory. The drop-out rate was only 12,5% and no serious adverse events were reported during the treatment. CONCLUSION: The results support that magnetic transcranial stimulation, as provided by this service is effective in treating treatment-resistant or longstanding depression in a real life clinical setting and the low drop-out rate supports that the treatment is generally very well tolerated.