Cognitive effects of bilateral high frequency repetitive transcranial magnetic stimulation in early phase psychosis: a pilot study

Cognitive dysfunction is a core facet of schizophrenia that is present early in the course of the illness and contributes to diminished functioning and outcomes. Repetitive transcranial magnetic stimulation (rTMS) is a relatively new neuropsychiatric intervention. Initially used in treatment resistant depression, investigators are now studying rTMS for other psychiatric diseases such as schizophrenia. In this study we examined the effect of high frequency rTMS on cognitive function in a group of individuals with early phase psychosis. Twenty subjects were randomized (1:1) in double-blind fashion to rTMS or sham condition. Over two weeks subjects underwent ten sessions of high frequency, bilateral, sequential rTMS targeting the dorsolateral prefrontal cortex (DLPFC). Prior to beginning and following completion of study treatment, subjects completed a cognitive assessment and magnetic resonance imaging. Subjects receiving rTMS, compared to sham treatment, displayed improvement on a standardized cognitive battery both immediately following the course of study treatment and at follow-up two weeks later. Imaging results revealed that left frontal cortical thickness at baseline was correlated with treatment response. The study treatment was found to be safe and well tolerated. These results suggest that rTMS may hold promise for the treatment of cognitive dysfunction in the early phase of psychosis, and that MRI may provide biomarkers predicting response to the treatment.