Gesture deficits in psychosis and the combination of group psychotherapy and transcranial magnetic stimulation: A randomized clinical trial

Hand gesture deficits are common in schizophrenia predicting poor social functioning with no treatment currently available. We used 10-sessions of repetitive transcranial magnetic stimulation (rTMS; 2-weeks) over the right inferior parietal lobe (IPL) in combination with 16-sessions of social cognitive remediation group therapy (SCRT; 8-weeks) to examine improvements in hand gesture performance in schizophrenia. In this 3-arm, double-blind, randomized, sham-controlled trial, 89 patients were randomized and 73 received at least one session of rTMS/SCRT: 19 patients were allocated to the real rTMS + real SCRT treatment, 26 to the sham rTMS + real SCRT treatment, and 28 to sham SCRT treatment. Hand gesture performance along with socio-cognitive and functional assessments were examined at 2-weeks, 8-weeks, and 32-weeks follow-up. Of 73 patients analyzed, (57% male), 53 completed the intervention and week-8 assessments. At week-8 no difference in overall hand gesture performance accuracy was observed across treatments. However, at week-32 follow-up the real rTMS + real group SCRT treatment showed significant improvements in novel unlearned gestures (F_{(6, 210)} = 2.2; p-value = 0.04), and significant gains in social functioning/personal performance at week-8 and sustained at week-32 follow-up (all F-values > 2.6; all p-values < 0.05). No treatment effects were found for overall hand gesture performance accuracy. However, improvements in secondary outcomes such as novel unlearned gestures and social/personal functioning hold promise for testing optimized rTMS + group SCRT combinations. Future studies should explore the neural effects of rTMS over right IPL + group SCRT.