Effort-Cost Decision-making Among Individuals With Schizophrenia: A Systematic Review and Meta-analysis

Abstract

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.

Figure 1.. Flowchart of the Selection Process of Effort-Cost Decision-making Studies of Schizophrenia

The keywords used were (effort* OR cost*) AND (schizophr* OR psychosis* OR psychotic*) AND (task* OR paradigm* OR battery*).

Figure 2.. Forest Plots of Effort-Cost Decision-making Performance Among Patients With Schizophrenia and Control Individuals

A and B, The dashed vertical lines correspond to the summary effect size found in each meta-analysis. Squares represent Hedges g effect sizes, with horizontal lines representing 95% CIs; the size of the squares represents weight. The diamond represents the summary effect sizes, with the outer points representing the 95% CIs. B, The curves correspond to the posterior distribution of each study and the summary effect sizes. EEfRT indicates effort expenditure for rewards tasks.^{,,,,,,,,,,,,,,,,,,,}

Figure 3.. Forest Plot of Association Between Negative Symptom Severity and Effort Allocation

Results are from a frequentist meta-analysis. The dashed vertical lines correspond to the summary effect size found in each meta-analysis. Squares represent Hedges g effect sizes, with horizontal lines representing 95% CIs; the size of the squares represents weight. BNSS indicates Brief Negative Symptom Scale; CAINS, Clinical Assessment Interview for Negative Systems; and SANS, Scale for the Assessment of Negative Symptoms.

Figure 4.. Forest Plots of Effort Expenditure for Rewards Tasks Performance in Each Condition

Results are from a frequentist meta-analysis between patients with schizophrenia and control individuals. The dashed vertical lines correspond to the summary effect size found in each meta-analysis. Squares represent Hedges g effect sizes, with horizontal lines representing 95% CIs; the size of the squares represents weight.