| Abstrakt: |
This systematic review and meta-analysis quantifies trade-offs between cognitive and physical effort allocation and rewards among individuals with schizophrenia compared with control individuals. Key Points: Question: Is schizophrenia associated with impairments on behavioral tests of decisions involving trade-offs between efforts and rewards? Findings: In this systematic review and meta-analysis of 20 studies (1503 participants), schizophrenia was associated with medium effect size deficits in effort allocation, as indexed by effort-cost decision-making tasks. The magnitude of the deficit was greater for high-reward trials; the deficit was significantly associated with negative symptom severity and was similar across measurement paradigms and effort types. Meaning: The findings suggest that individuals with schizophrenia have less willingness to perform an effort for large rewards and that reduction of goal-directed behaviors in schizophrenia may be mediated by inflated subjective effort cost. Importance: Motivational impairments in schizophrenia are by definition associated with poor outcome. It is postulated that the reduction of goal-directed behavior arises from abnormal trade-offs between rewards and efforts. Objective: To examine whether schizophrenia is associated with impairments in effort-cost decision-making. Data Sources: For this systematic review and meta-analysis, the PubMed, ScienceDirect, PsycINFO, Embase, and ClinicalTrials.gov databases were searched from inception to July 2022 for studies that investigated effort-cost decision-making in schizophrenia. Search terms included effort, cost, and schizophrenia. Study Selection: Consensual criteria for inclusion were peer-reviewed studies published in English that used a computerized effort-cost decision-making behavioral paradigm and compared individuals with schizophrenia with control individuals. Data Extraction and Synthesis: The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline was used for abstracting data. Data were extracted independently by 2 authors and then pooled using random-effects sizes and bayesian approaches. Main Outcomes and Measures: The main outcomes were performance on effort-cost decision-making tasks requiring an effort-reward trade-off, measured by Hedges g effect size. Effects of moderators were tested with meta-regressions and subgroup analyses. Results: Twenty studies involving 1503 participants were included: 837 individuals with schizophrenia (541 [64.6%] male; mean [SD] age, 35.89 [6.70] years) and 666 control individuals without schizophrenia (360 [54.1%] male; mean [SD] age, 34.16 [5.92] years). Participants with schizophrenia had significantly reduced willingness to expend effort for rewards compared with controls (k = 20; effect size, 0.43; 95% CI, 0.30-0.56; P <.001; I2 = 33.1%; Q test P =.08). The magnitude of the deficit was significantly greater for high-reward trials. The severity of negative symptoms was negatively associated with effort-cost decision-making (k = 8; effect size, −0.33; 95% CI, −0.50 to −0.15; P <.001), while participants with a high number of negative symptoms had a significantly larger impairment in effort-cost decision-making (k = 5; effect size, 0.47; 95% CI, 0.10-0.84; P =.01). Conclusions and Relevance: In this systematic review and meta-analysis, schizophrenia was associated with deficits in effort allocation as indexed by effort-cost decision-making tasks. Understanding the cognitive and neurobiological mechanisms driving effort allocation impairments may assist in developing novel interventions. [ABSTRACT FROM AUTHOR] |
