Amotivational symptoms are observed in schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD).Effort-cost computation may be a potential contributor to amotivation transdiagnostically. This study examined effort-cost computation in these three diagnostic groups. This study recruited 141 outpatients (49 SCZ, 52 non-psychotic BD, and 40 non-psychotic MDD) and 57 healthy controls (HCs). We administered the Effort-Expenditure for Reward Task (EEfRT), which manipulated different levels of reward magnitude and probability relating to a high and low physical effort task. There were significant interactions between group and reward magnitude, group and reward probability, and group and expected value on the percentage of high-effort choices. SCZ, BD, and MDD patients made comparably fewer high-effort choices than HCs in the high-reward magnitude, high-reward probability, and highexpected-value conditions. Self-reported amotivation did not correlate with decision-making on the EEfRT. Our findings suggest that reduced effort expenditure for reward is a transdiagnostic phenotype in SCZ, BD, and MDD.

Background: Although Theory of Mind (ToM) impairment has been observed in patients with a wide range of mental disorders, the similarity and uniqueness of these deficits across diagnostic groups has not been thoroughly investigated. Methods: We recruited 35 participants with schizophrenia (SCZ), 35 with bipolar disorder (BD), 35 with major depressive disorder (MDD), and 35 healthy controls in this study. All participants were matched in age, gender proportion and IQ estimates. The Yoni task, capturing both the cognitive and affective components of ToM at the first-and second-order level was administered. Repeated-measure ANOVA and MANOVA were conducted to compare the group differences in ToM performance. A network was then constructed with ToM performances, psychotic and depressive symptoms, and executive function as nodes exploring the clinical correlates of ToM. Results: Overall, ToM impairments were observed in all patient groups compared with healthy controls, with patients with SCZ performing worse than those with BD. In second-order conditions, patients with SCZ and MDD showed deficits in both cognitive and affective conditions, while patients with BD performed significantly poorer in cognitive conditions. Network analysis showed that second-order affective ToM performance was associated with psychotic and depressive symptoms as well as executive dysfunction, while second-order affective ToM performance and negative symptoms showed relatively high centrality in the network. Conclusions: Patients with SCZ, MDD and BD show different variety and severity of impairments in ToM sub-components. Impairment in higher-order affective ToM appears to be closely related to clinical symptoms in both psychotic and affective disorders.

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