Trial reportThe American journal of psychiatry2013
Metformin for weight loss and metabolic control in overweight outpatients with schizophrenia and schizoaffective disorder.
Trial report in The American journal of psychiatry, 2013. The graph read 2 numbers from its abstract, feeding 1 cell of the map: it supports the treatment in 1. It is linked to trial NCT02796144 (Metformin and Lorcaserin for Weight Loss in Schizophrenia), which is not on this map. Cited by 50 papers, 12 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
Mean change in body weight was -3.0 kg (95% CI=-4.0 to -2.0) for the metformin group and -1.0 kg (95% CI=-2.0 to 0.0) for the placebo group, with a between-group difference of -2.0 kg (95% CI=-3.4 to -0.6).
Mean change in body weight was -3.0 kg (95% CI=-4.0 to -2.0) for the metformin group and -1.0 kg (95% CI=-2.0 to 0.0) for the placebo group, with a between-group difference of -2.0 kg (95% CI=-3.4 to -0.6).
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Where it lands on the map
Rows are treatments, columns are outcomes. The coloured squares are the cells this paper feeds, coloured by the vote it casts there. Click one to jump to what this paper adds to it.
What it adds to each cell
For every cell the paper feeds: the belief in the claim with and without this paper, and this paper's estimate drawn against every other readable study in the cell. The ringed dot is this paper.
Metformin×body weight & composition
SupportsOpen on the map →What to test next →19 readable studies in this cell: 7 favour the treatment, 6 find no difference, 6 favour the comparator.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Metformin and Lorcaserin for Weight Loss in Schizophrenia
Who cites it
50 citing papers in PubMed, 12 syntheses or guidelines pooled it, 144 citations in OpenAlex.
- The Optimal Dosage and Duration of Metformin for Prevention and Treatment of Antipsychotic-Induced Weight Gain: An Updated Systematic Review and Meta-Analysis.Schizophrenia bulletin · 2025Pooled it
- Insulin effects on core neurotransmitter pathways involved in schizophrenia neurobiology: a meta-analysis of preclinical studies. Implications for the treatment.Molecular psychiatry · 2023Pooled it
- Pharmacological interventions for prevention of weight gain in people with schizophrenia.The Cochrane database of systematic reviews · 2022Pooled it
- Interventions for preventing type 2 diabetes in adults with mental disorders in low- and middle-income countries.The Cochrane database of systematic reviews · 2021 · on this mapPooled it
- Pharmacological Interventions to Treat Antipsychotic-Induced Dyslipidemia in Schizophrenia Patients: A Systematic Review and Meta Analysis.Frontiers in psychiatry · 2021Pooled it
- Adjunctive metformin for antipsychotic-induced dyslipidemia: a meta-analysis of randomized, double-blind, placebo-controlled trials.Translational psychiatry · 2020Pooled it
- Effects of metformin on blood lipid profiles in nondiabetic adults: a meta-analysis of randomized controlled trials.Endocrine · 2020Pooled it
- Role of metformin in overweight and obese people without diabetes: a systematic review and network meta-analysis.European journal of clinical pharmacology · 2019Pooled it
- The effects of metformin on simple obesity: a meta-analysis.Endocrine · 2018Pooled it
- The Effectiveness of Pharmacological and Non-Pharmacological Interventions for Improving Glycaemic Control in Adults with Severe Mental Illness: A Systematic Review and Meta-Analysis.PloS one · 2017 · on this mapPooled it
- Metformin in prevention and treatment of antipsychotic induced weight gain: a systematic review and meta-analysis.BMC psychiatry · 2016 · on this mapPooled it
- Pharmacological strategies to counteract antipsychotic-induced weight gain and metabolic adverse effects in schizophrenia: a systematic review and meta-analysis.Schizophrenia bulletin · 2014Pooled it
- Effect of GLP-1 receptor agonist treatment on body weight in obese antipsychotic-treated patients with schizophrenia: a randomized, placebo-controlled trial.Diabetes, obesity & metabolism · 2017Trial
- Weight gain and 10-year cardiovascular risk with sustained tobacco abstinence in smokers with serious mental illness: a subgroup analysis of a randomized trial.The Journal of clinical psychiatry · 2016Trial
- Trial
- The Effect of Semaglutide on Antipsychotic-Induced Weight Gain and Other Metabolic Parameters, among a Cohort of Inpatients.Schizophrenia bulletin · 2026Article
- Novel drug treatments for schizophrenia.Nature reviews. Drug discovery · 2026Review
- Weight gain under antipsychotic and mood stabilizing treatment: a narrative review about mechanisms and future options.International journal of bipolar disorders · 2025Review
- Metabolic syndrome in patients with schizophrenia: Underlying mechanisms and therapeutic approaches (Review).Molecular medicine reports · 2025Review
- Article
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Authors and funding
10 authors at 2 institutions in 1 country.
Funding
Abstract
The marked sentences are the ones the graph read a number from.
objectiveThe purpose of this study was to determine whether metformin promotes weight loss in overweight outpatients with chronic schizophrenia or schizoaffective disorder.
methodIn a double-blind study, 148 clinically stable, overweight (body mass index [BMI] ≥27) outpatients with chronic schizophrenia or schizoaffective disorder were randomly assigned to receive 16 weeks of metformin or placebo. Metformin was titrated up to 1,000 mg twice daily, as tolerated. All patients continued to receive their prestudy medications, and all received weekly diet and exercise counseling. The primary outcome measure was change in body weight from baseline to week 16.
resultsFifty-eight (77.3%) patients who received metformin and 58 (81.7%) who received placebo completed 16 weeks of treatment. Mean change in body weight was -3.0 kg (95% CI=-4.0 to -2.0) for the metformin group and -1.0 kg (95% CI=-2.0 to 0.0) for the placebo group, with a between-group difference of -2.0 kg (95% CI=-3.4 to -0.6). Metformin also demonstrated a significant between-group advantage for BMI (-0.7; 95% CI=-1.1 to -0.2), triglyceride level (-20.2 mg/dL; 95% CI=-39.2 to -1.3), and hemoglobin A1c level (-0.07%; 95% CI=-0.14 to -0.004). Metformin-associated side effects were mostly gastrointestinal and generally transient, and they rarely led to treatment discontinuation.
conclusionsMetformin was modestly effective in reducing weight and other risk factors for cardiovascular disease in clinically stable, overweight outpatients with chronic schizophrenia or schizoaffective disorder over 16 weeks. A significant time-by-treatment interaction suggests that benefits of metformin may continue to accrue with longer treatment. Metformin may have an important role in diminishing the adverse consequences of obesity and metabolic impairments in patients with schizophrenia.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.