Yoga therapy could improve social cognition in schizophrenia, NIMHANS study

An experimental medicine-based randomized controlled trial conducted by NIMHANS, Bengaluru has shown that 6 weeks of add-on yoga therapy could improve social cognition in schizophrenics compared to waitlist control subjects. The study was published recently in Asian Journal of Psychiatry by Govindaraj et al.

Negative symptoms and cognitive deficits are difficult-to-treat symptoms of schizophrenia. Broadly cognitive symptoms could be classified as neurocognition or social cognition deficits. Most frequently studied aspects of social cognition in schizophrenia are Theory of Mind (ToM), Emotion processing (EP), Social perception (SP), Social knowledge, and Attribution Style (AS).

Except for the positive symptoms, there are no effective treatments available for the negative and cognitive symptoms including social cognition deficit. The majority of psychosocial therapies [for example, Cognitive Enhancement Therapy (CET), Social Cognition Interaction Training (SCIT)] are highly resource-intensive and their feasibility in developing countries is questionable.

In healthy adults and the elderly, yoga is found to be efficacious in improving cognitive skills. As an add-on treatment, yoga is more effective than physical exercise in reducing the negative symptoms in persons with schizophrenia (PWS).

Govindaraj et al adopted the experimental medicine-based approach for simultaneous investigation of the effect of add-on yoga therapy on social cognition and the underlying putative biological mechanism in PWS.

In this single blind randomized controlled study, they compared change in social cognitive performance in PWS, after 6 weeks of yoga intervention with a waitlist control group. Validated Yoga module was administered to the Yoga group for 60 min, 4–5 sessions per week, with a total of 20 sessions to be completed within 6 weeks.

Authors 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) (P < 0.001); negative symptoms (SANS) (P < 0.001); positive symptoms (SAPS) (P < 0.001) and social disability (GSDS) (P < 0.001). MNS activity had increased after 6 weeks in both groups but not of statistical significance.

This is one of the first studies exploring the role of yoga in social cognition mediated by MNS activity. The results indicate that PWS who received the yoga intervention over 6-weeks showed significant improvement in social cognition performance as compared to those in the waitlist group.

"From patients' perspective, our results suggest that they could engage better in their day to day social interactions, which forms one of the vital aspect of an individual's role functioning in the society", note the authors in discussion.

The yoga module for schizophrenia used in this study primarily focuses on coordinating body postures with breathing while encouraging an internal monitoring process as individuals perform these asanas. The latter process is likely to modulate brain regions that are associated with selfprocessing, self-reflection, and mentalization such as medial prefrontal and posterior cingulate cortices.

The process of performing coordinated body postures includes imitating the trainer and experiencing one's own movements and postures being imitated by others in the training group. This iterative process of imitating and being imitated is likely to facilitate the release of oxytocin.

Yoga therapy could hence activate the mirror neuron system – a key hub within the social brain system that drives social inferences in goal-directed actions through a process of embodied simulation.

Given that, there is a fairly consistent report of improved social cognition with yoga therapy, this combined effect of yoga on core social physiological processes relevant to social cognition and schizophrenia may be examined in future studies.

"The results of this study are very relevant from a clinical perspective as there are no effective pharmacological or biological treatments to manage the cognitive dysfunction, especially social cognitive deficit in PWS", conclude the authors.

Source: Asian Journal of Psychiatry: https://doi.org/10.1016/j.ajp.2021.102731