Breaking the Cycle: Rewiring Negative Symptoms in Schizophrenia Through Physical Exercise

Individuals with schizophrenia commonly exhibit debilitating negative symptoms, including avolition and anhedonia, which represent a significant barrier to engagement in goal-directed behaviours, including physical exercise. They are less physically active than the general population, yet physical exercise is known to improve their symptoms. This narrative review investigates the bidirectional relationship between negative symptoms and physical activity. We propose that negative symptoms hinder engagement in physical activity by altering the cost-benefit analysis of exercise. This is exacerbated by deficits in anticipatory pleasure and reward learning, underpinned by dysfunctions within dopaminergic and glutamatergic circuitry which are critical for motivated behavior. We hypothesise that physical exercise can rewire these deficits through enhanced dopamine transmission, modulation of glutamatergic and GABAergic systems, and reduced inflammation. Furthermore, grounded in learning theories and adopting a cognitive-behavioural perspective, this review establishes a theoretical foundation for developing targeted interventions designed to enhance physical activity engagement in this population. We highlight that it is critical to ensure that physical activity is experienced as less effortful and more pleasurable than expected. By generating positive prediction errors (when the experience of exercise is less effortful or more pleasurable than anticipated) exercise helps individuals re-associate it with positive outcomes. Cognitive changes coupled with the biological effects of physical exercise on reward neural pathways are likely to have a synergistic effect, promoting a virtuous cycle of sustained engagement and symptom improvement.