Transcranial magnetic stimulation in schizophrenia: exploring dosage and working memory enhancement

Abstract

Schizophrenia often presents with working memory impairment, associated with abnormal dorsolateral prefrontal cortex activation. While noninvasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS), have demonstrated effective working memory enhancement in healthy individuals with just one session of stimulation, the same protocol has not shown similar improvements in working memory for individuals with schizophrenia. Here, we briefly review the TMS and working memory literature in schizophrenia and highlight the possible role of TMS dosage. Specifically, previous studies with fewer than 20 TMS sessions show limited response, while studies with 20 sessions present mixed findings. Interestingly, a higher number of sessions, notably 40, reveal a potentially promising effect on working memory improvement, albeit with delayed manifestation. The optimal TMS dosage for robust neural plasticity remains unclear. Future research should explore increased TMS sessions, coupled with longer follow-up durations, to comprehensively investigate working memory enhancement in schizophrenia.