Effort-cost computation in a transdiagnostic psychiatric sample: Differences among patients with schizophrenia, bipolar disorder, and major depressive disorder.

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 high-expected-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.

Influence of GNB3 C825T polymorphism on the efficacy of antidepressants in the treatment of major depressive disorder: A meta-analysis.

OBJECTIVE: We performed the present meta-analysis in order to evaluate the influence of a common polymorphism (C825T, rs5443 C>T) in the GNB3 gene on the efficacy of antidepressants in the treatment of major depressive disorder (MDD). METHOD: A relevant literature was searched using the PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, CBM and CNKI databases without any language restrictions. STATA Version 12.0 software (Stata Corporation, College Station, Texas USA) was used for this meta-analysis. Odds ratio (OR) and its corresponding 95% confidence interval (95% CI) were calculated. RESULTS: Our findings suggested that the GNB3 C825T polymorphism was significantly correlated with a higher response rate to antidepressants in MDD patients under the allele and dominant models. Furthermore, we found significant associations between GNB3 C825T polymorphisms and antidepressant-induced remission in MDD patients. Ethnicity-stratified analysis indicated that GNB3 C825T polymorphisms may be strongly related to the efficacy of antidepressants in the treatment of MDD among Asians, but not in Caucasians (all P>0.05). CONCLUSION: Our findings provide empirical evidence that GNB3 C825T polymorphisms may be correlated with the efficacy of antidepressants in the treatment of MDD, especially among Asians patients.