TMS in child and adolescent major depression

Transcranial magnetic stimulation (TMS) can be used both to investigate the brain’s excitatory and inhibitory functions and to modulate the activity of cortical circuits. Prior neurophysiologic studies using single- and paired-pulse TMS have indicated excessive glutamatergic cortical facilitation in depressed children and adolescents, suggesting that dysregulations in glutamate function and neurotransmission may have a role in some forms of early-onset depression. A small number of open-label trials of high-frequency repetitive TMS (rTMS) in depressed children and adolescents have shown encouraging results for antidepressant effectiveness, and rTMS has been well tolerated with few serious adverse effects. For practical reasons, early rTMS protocols for adolescent depression have utilized adult dosing patterns. To date, no randomized controlled trials of rTMS for adolescent depression have been published. Despite these promising advances, currently many questions remain about how to optimize dosing parameters in the context of neurodevelopment and the use of newer forms of rTMS, such as theta burst stimulation. Planned and ongoing studies will address these knowledge gaps. Future work also will continue to refine stimulation targeting via anatomical and functional imaging-guided approaches.