Enhancement of aerobic fitness improves social functioning in individuals with schizophrenia

Individuals with schizophrenia display substantial deficits in social functioning (SF), characterized by chronic, lifelong presentations. Yet, at present there are few effective interventions to enhance SF in this population. Emerging evidence from studies of clinical populations that display similar SF deficits suggests that aerobic exercise (AE) may improve social skills. However, this putative impact has not been investigated in schizophrenia. Employing a single-blind, randomized clinical trial design, 33 individuals with schizophrenia were randomized to receive 12 weeks of Treatment-As-Usual (TAU; n = 17) or TAU + AE (n = 16) utilizing active-play video games (Xbox 360 Kinect) and traditional AE equipment. Participants completed an evaluation of aerobic fitness (VO₂max) as well as self-, informant-, and clinician-reported SF measures at baseline and after 12 weeks. Twenty-six participants completed the study (79%; TAU = 13; AE = 13). At follow-up, the AE participants improved their VO₂max by 18.0% versus - 0.5% in the controls (group x time interaction, F_1,24 = 12.88; p = .002). Hierarchical stepwise regression analyses indicated improvements in VO₂max significantly predicted enhancement in SF as indexed by self-, informant-, and clinician-reported measures, predicting 47%, 33%, and 25% of the variance, respectively (controlling for baseline demographics, medications, mood symptoms, and social networks). Compared to the TAU group, AE participants reported significant improvement in SF (23.0% vs. - 4.2%; group × time interaction, F_1,24 = 7.48, p = .012). The results indicate that VO₂max enhancement leads to improvements in SF in people with schizophrenia. Furthermore, low VO₂max represents a modifiable risk factor of SF in people with schizophrenia, for which AE training offers a safe, non-stigmatizing, and nearly side-effect-free intervention.