Yoga exercise for cognitive impairment in psychotic disorders

Abstract

BACKGROUND: Cognitive impairment is evident in early stage of psychosis and can result in severe and longstanding functional impairment. Pharmacological interventions for cognitive impairments have been largely unsuccessful. The current study aimed to explore the effects of yoga exercise and aerobic exercise on cognitive functions, clinical conditions and brain structure in female patients with psychotic disorders. METHODS: Eighty-five female patients with psychotic disorders were recruited from three early intervention service units for psychosis. They were randomized into integrated yoga exercise group, aerobic exercise group and control group. At baseline and 12 weeks, clinical symptoms, cognitive functions, quality of life and fitness levels were assessed in all patients. Thirty-nine patients completed structural MRI assessment to compare the brain volume and cortical thickness. Repeated measures ANOVA and ANCOVA analyses of the clinical, cognitive, quality of life and fitness data were done between baseline and 12 weeks among the three groups. Post-hoc Bonferroni test was used for comparison between yoga exercise group and aerobic exercise group. RESULTS: Both yoga and aerobic exercise groups demonstrated significant improvements in verbal encoding (p<0.01), short-term memory (p<0.05), long-term memory (p<0.01), and working memory (p<0.01) with moderate to large effect sizes compared to control group. The yoga group showed significantly enhanced attention and concentration (p<0.05). Both yoga and aerobic exercise significantly improved overall clinical symptoms (p<0.05) and depressive symptoms (p<0.05) after 12 weeks. Significant increase was observed in the thickness of the left superior frontal gyrus and the right inferior frontal gyrus in the aerobic exercise group. Significant increase was observed in the volume of the postcentral gyrus and the posterior corpus callosum in the yoga exercise group. There was a statistically significant correlation between improvements in working memory and changes in the postcentral gyrus (r=0.54, p<0.01). CONCLUSION: Both yoga and aerobic exercise improved memory in patients with psychotic disorder and yoga exercise showed a superior effect on attention than aerobic exercise. The improvement in working memory was associated with change in the volume of postcentral gyrus. The present study indicates possible interventions for cognitive impairments in the patients with psychotic disorder. The application of yoga and aerobic exercise as adjunct treatments in early intervention of psychosis in the clinical setting should be advocated.