A systematic review revealed the promising potential of neuromodulation, particularly transcranial magnetic stimulation to manage somatic symptom and functional neurological disorders. Databases like PsycINFO, Medline, and Embase were systematically searched for trials assessing neuromodulation devices to treat complex neuropsychiatric conditions.

Variables such as psychiatric comorbidity, study design, demographic and clinical characteristics,  neurostimulation protocols, results, and clinical outcome measures were extracted.  In total, 404 studies were recognized with 12 fulfilling the inclusion criteria. Overall, 221 subjects were treated in the incorporated studies with a mean study sample size of 18. There were 5 randomized clinical trials and the most studied subpopulations were functional motor symptoms.

Transcranial magnetic stimulation was the most commonly utilized device (10 studies), which was followed by electroconvulsive therapy (1 study) and direct-current stimulation (1 study). The therapeutic protocols varied in the intended therapeutic mechanisms: 8 studies aimed to modulate the underlying network dysfunctioning, 5 aimed to show movement (1 also leveraged the former) and 3 boosted their primary mechanism with improved suggestion/expectation.

All but 1 study displayed positive findings. But, small sample sizes, methodological/outcome heterogeneity, and mixed study quality precluded quantitative meta-analysis. In patients with functional motor symptoms, neuromodulation, especially transcranial magnetic stimulation was found to show preliminary promise in numerous investigations.

Thus, neuromodulation is a new therapeutic approach capable of modulating brain networks, making it a suitable candidate to treat patients with complex neuropsychiatric conditions. Larger, robust, sham-controlled studies are warranted for further establishing efficacy and better understanding therapeutic mechanisms.