Trait Anhedonia in Schizophrenia: A Systematic Review and Comparative Meta-analysis
Bibliographic record
Abstract
Anhedonia, the reduced capacity to experience pleasure, has long been considered a prominent feature of schizophrenia spectrum disorders. Many domain-specific conceptualizations of anhedonia and pleasure capacity have been developed, and there currently exist a variety of self-report assessment tools that purport to assess these various domains. The current systematic review and meta-analysis (PROSPERO: CRD42020156169) aimed to quantify overall and domain-specific self-reported anhedonia in people with schizophrenia compared to nonpsychiatric controls. We performed a literature search of PsycINFO, MEDLINE, and Embase databases for dissertations and peer-reviewed articles published in English prior to June 2021. Studies employing a psychometrically validated self-report measure of anhedonia, pleasure experience or affect in people with schizophrenia, schizoaffective, or schizophreniform disorders; studies utilizing at least one clearly defined healthy or community control group for comparison; and studies providing sufficient data to calculate effect sizes were included in this review. Random and mixed effects meta-analyses, meta-regressions, and subgroup comparisons were run across domains of anhedonia to explore weighted mean effect sizes and their associated moderators. In total, 146 studies met inclusion criteria, yielding 390 Hedges' g effect sizes from the included comparisons. People with schizophrenia reported moderate-to-large elevations in overall and domain-specific anhedonia. A sensitivity analysis accounting for high risk of bias studies did not significantly impact results. Lastly, patient sex, education, negative symptom severity, antipsychotic class, and trait negative affect differentially moderated effect sizes across domains of anhedonia. Despite the heterogeneity inherent in schizophrenia spectrum disorders, self-reported anhedonia is ubiquitously reported across self-report measures in this population.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.031 | 0.008 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".