Reduced option generation reveals distinct profiles of apathy in schizophrenia

Apathy is a major driver of long-term disability in schizophrenia, yet existing accounts focus on how patients evaluate the cost of action while neglecting their capacity to generate options for action in the first place. Using a brief, culture-fair option generation task (OGT) within the international CHANSS study, we examined this process in 150 patients with different stages of schizophrenia and 100 healthy controls across the UK, Spain, and China. The OGT requires drawing as many different paths as possible between two points on a touchscreen, yielding two measures: fluency (the number of paths that they generate) and uniqueness (the distinctiveness of those paths). Patients drew as many paths as controls but produced options roughly half as unique. Across patients, uniqueness was positively associated with verbal fluency and depressive symptom severity, but negatively associated with self-reported behavioural apathy. This suggests that increased apathy is associated with reduced ability to generate unique options (paths on the task). To examine the cognitive mechanisms further, we decomposed uniqueness into four exploratory measures: roaming entropy (spatial breadth of exploration), option elaboration (within-path development), perseveration (local repetition), and novelty maintenance (sustaining diversity over time). Together these explained 69% of the variance in motor-residualised uniqueness and attenuated the group difference by 80%, with roaming entropy as the dominant contributor. K-means clustering revealed three distinct patient profiles, each with a different clinical signature. A small subgroup generated options much like the control group. A larger subgroup retained spatial exploration but developed each option less and reported more depressive symptoms. A third subgroup showed broadly impaired exploration and the lowest verbal fluency. These findings establish option generation as a measurable behavioural phenotype in schizophrenia that relates to apathy and can be decomposed into specific cognitive mechanisms. They suggest that an impoverished option space, marked by reduced generation of unique possibilities for action, may be a remediable component of apathy.