The impact of exercise interventions on the network structure of psychotic symptoms: analysis from two clinical trials

Background and hypothesis In people with psychotic disorders, exercise interventions are known to improve psychotic symptoms, however, the mechanisms underlying these effects are unclear. In the network approach, mental disorders are conceptualized as complex systems of interacting symptoms. In this context, exercise interventions could modify the dynamic of psychotic symptoms within the network. Using data from two independent clinical trials using exercise, the aim was to investigate the impact of exercise interventions on network connectivity, then compare the network structure pre and post intervention. Study designCombined data from two clinical trials on exercise with a total of 106 participants with a diagnostic of psychotic disorder were included. The Positive and Negative Syndrome Scale (PANSS) was used to assess symptoms severity using semi-structured interviews. Networks before and after PE were performed. Study results At baseline, the PANSS network was densely connected with several strong positive con-nections between the symptoms with negative symptoms being the most central. After exercise, the network was less dense and less connected, and the connections were dif-ferent. When the networks before and after exercise were compared, they were signifi-cantly different in terms of structure, but not global strength. Conclusion This study is the first to show that exercise seems to favor a disconnection between psychotic symptoms, and could modify the network structure, providing a first mechanism of action which would require more investigation.