Yoga therapy for social cognition in schizophrenia: An experimental medicine-based randomized controlled trial.

Negative symptoms and cognitive deficits are difficult-to-treat symptoms of schizophrenia. In this single blind randomized controlled study, we compared change in social cognitive performance in persons with Schizophrenia (PWS) (as per DSM-5), after 6 weeks of yoga intervention with a waitlist control group. We also examined changes in putative Mirror Neuron System (MNS) activity measured by Transcranial Magnetic Stimulation (TMS) in a subset of sample (n = 30). 51 PWS stabilized on antipsychotic medication for at least 6 weeks, were assigned to add-on yoga therapy (YT) (n = 26) or waitlist (WL) (n = 25). Subjects in the YT group received add-on yoga therapy (20 sessions in 6 weeks). Both the groups continued their standard treatment and were assessed at baseline and after 6 weeks for social cognition, clinical symptoms and social disability. RM-ANOVA showed significant interaction between time and group for social cognition composite score (SCCS) (F = 42.09 [1,44], P < 0.001); negative symptoms (SANS) (F = 74.91 [1,45], P < 0.001); positive symptoms (SAPS) (F = 16.05 [1,45], P < 0.001) and social disability (GSDS) (F = 29.91 [1,46], P < 0.001). MNS activity had increased after 6 weeks in both groups but not of statistical significance. This study demonstrates that 6 weeks of add-on yoga therapy could improve social cognition in PWS compared to waitlist control subjects. However, the change in social cognition was not associated with a change in the putative MNS-activity. It necessiatates further studies to investigate the mechanistic processes of yoga and replicate these observations in a larger sample.