Brain Stimulation in Pediatric Depression: Biological Mechanisms.

Transcranial direct-current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) are non-invasive brain stimulation (NIBS) modalities with therapeutic promise in childhood neuropsychiatric disorders. Although data are limited, prior studies have examined potential therapeutic utility in childhood mood disorders, attention-deficit hyperactivity disorder, autism, Tourette syndrome, and schizophrenia. Both techniques are thought to modulate the activity and excitability of disrupted neural networks. However, a refined knowledge of biological mechanisms could inform future clinical trials and practice. This is particularly critical for safety and optimizing the clinical potential of these treatments in youth. Prior mechanistic studies of NIBS include preclinical models, neurophysiology markers, neuroimaging, neurocognitive measures, and peripheral biomarkers. The majority of these investigations focused on adults with depression. This chapter will review the extant research on the biology of therapeutic tDCS and rTMS in depression. Much of this work focuses on adults but is considered in a developmental context with the aim of informing future research and clinical practice in youth.