No evidence of a control group response in exercise randomised controlled trials in people with schizophrenia: A systematic review and meta-analysis

• Control group responses make it more difficult to demonstrate an interventions effectiveness.
• We conducted the first meta-analysis to investigate if a control group response exists in exercise RCTs in schizophrenia.
• We found no evidence of a control group response in total, negative or positive symptoms of schizophrenia.
• Our results add weight to the beneficial effect of exercise in improving total and negative symptoms.

Increased control group responses (CGR) make it more difficult to establish the effectiveness of interventions to improve symptoms in schizophrenia. We conducted a meta-analysis of CGR within randomised control trials (RCTs) comparing exercise and a control condition in people with schizophrenia. We found no evidence of a CGR for total, positive or negative symptoms. Control group responses do not negatively impact exercise RCTs that have clearly demonstrated substantial beneficial effects of exercise in this population.