Computational Modeling of Effort Allocation in First-Episode Psychosis and First-Episode Bipolar Disorder: Cognitive and Clinical Correlates

AI Summary

First-episode psychosis and first-episode bipolar disorder participants chose the high-effort option less as reward probability and magnitude increased, compared with controls.
Hierarchical drift diffusion modelling revealed altered influence of reward magnitude and probability on effort-based decisions in patient groups, with greater alterations in FEP.
Findings indicate disrupted integration of reward information during effort-cost computation in early psychotic and bipolar illness, suggesting shared motivational mechanisms despite clinical stability.

Biol Psychiatry Cogn Neurosci Neuroimaging. 2026 Nov 10:S2451-9022(26)00339-3. doi: 10.1016/j.bpsc.2026.10.016. Online ahead of print.

ABSTRACT

BACKGROUND: Motivational deficits can be seen in bipolar disorder, as in schizophrenia. However, whether such deficits reflect a shared transdiagnostic impairment across psychotic and bipolar disorders from the early stages of illness remains unclear.

METHODS: This study examined effort expenditure for reward in individuals with first-episode psychosis (FEP) and first-episode bipolar disorder (FEBD), compared with healthy controls (HC). We also evaluated the relationship of these deficits in willingness to exert effort to clinical ratings and global cognition. Effort-cost decision-making (ECDM) was evaluated in the FEP (n=44), the FEBD (n=46), and HC groups (n=41) using Effort-Expenditure for Rewards Task (EEfRT).

RESULTS: The probability × reward × group interaction was significant in the EEfRT (F = 5.12, p < .001). This study showed that participants with FEP and FEBD were less likely to choose the harder task and maximize their reward, as the probability of obtaining the reward and the reward magnitude increased. Hierarchical drift diffusion modeling further demonstrated that reward magnitude and probability influenced effort-based decisions differently in patient groups relative to controls, with more pronounced alterations in FEP.

CONCLUSIONS: These findings suggest disrupted integration of reward-related information during effort-cost computation in the early stages of psychotic and bipolar disorders. Deficits in ECDM, while the patients were clinically stable, may indicate shared mechanisms in motivation in psychosis and bipolar disorder. The underlying mechanisms contributing to motivational abnormalities need to be clarified to create novel intervention strategies in the early stages of the disorders.

PMID:43009099 | DOI:10.1016/j.bpsc.2026.10.016

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