Metformin Tested for Antipsychotic-Related Weight Gain in Adults With Intellectual Disability
Tests metformin against a placebo for weight gain in adults with intellectual disability.
Plain-language title generated from the registry record
Registry title: Metformin for Antipsychotic-induced Weight Gain in Adults With Intellectual Disability
Key facts
- Where
- Toronto, CanadaSee the site
- Phase
- Phase 4
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 16 and 65 years old?
Source: NCT05744479, who can take part
Where in Canada
- Centre for Addiction and Mental HealthToronto, CanadaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Centre for Addiction and Mental Health
- Trial code
- NCT05744479
- Record updated
- 31 March 2026
- Original description
People with IDD (intellectual and developmental disability) have very high rates of obesity and die prematurely from cardiometabolic disease. While antipsychotics contribute to this problem, their use is necessary and appropriate in a significant subgroup of individuals with IDD. Exercise and diet interventions have limitations and may not be sufficient, requiring effective adjunctive pharmacological approaches to target obesity and related comorbidities in IDD. However, persons with IDD treated with antipsychotics are systematically excluded from clinical trials hindering development of evidence to help guide safe and effective treatment of these comorbidities. Moreover, evidence from other disorders cannot be extrapolated to IDD given inherent biological differences between disorders. This trial will address the identified gaps, which extend beyond cardiovascular morbidity and negatively impact psychosocial outcomes, in a hugely underserviced population.This is the the first RCT (randomized control trial) to examine the efficacy of metformin in overweight or obese adults with IDD who have experienced antipsychotic-induced weight gain. By generating efficacy data for a very accessible and scalable intervention, allows for guideline and implementation strategies to address a recalcitrant health problem.Read full original descriptionShow less
Metformin for Antipsychotic-induced Weight Gain in Adults With Intellectual Disability: A Double-Blind Randomized Control Trial
People with IDD (intellectual and developmental disability) have very high rates of obesity and die prematurely from cardiometabolic disease. While antipsychotics contribute to this problem, their use is necessary and appropriate in a significant subgroup of individuals with IDD. Exercise and diet interventions have limitations and may not be sufficient, requiring effective adjunctive pharmacological approaches to target obesity and related comorbidities in IDD. However, persons with IDD treated with antipsychotics are systematically excluded from clinical trials hindering development of evidence to help guide safe and effective treatment of these comorbidities. Moreover, evidence from other disorders cannot be extrapolated to IDD given inherent biological differences between disorders. This trial will address the identified gaps, which extend beyond cardiovascular morbidity and negatively impact psychosocial outcomes, in a hugely underserviced population.This is the the first RCT (randomized control trial) to examine the efficacy of metformin in overweight or obese adults with IDD who have experienced antipsychotic-induced weight gain. By generating efficacy data for a very accessible and scalable intervention, allows for guideline and implementation strategies to address a recalcitrant health problem.
Inclusion: Stable outpatients; Age 16-65 years; Diagnosed with an IDD; On maintenance treatment with an antipsychotic (stable dose for ≥3 months); BMI must be ≥30 kg/m2, OR ≥27 kg/m2 with at least one weight-related comorbidity (treated or untreated) such as: hypertension, dyslipidaemia, obstructive sleep apnea, or impaired fasting glucose, OR >=25 for individuals who have gained > 5% body weight in association with AP use; Females of child-bearing age must be on one of the following regular contraceptives:; Agree to abstain from sex for the duration of the trial or; A barrier method of a diaphragm with spermicide and/or Latex condom or; An oral contraceptive agent, implantable contraceptive or an injectable contraceptive for at least six months prior to entering the study and will continue its use throughout the study, or; An intrauterine device, or; Partner has had a vasectomy at least 3 months prior to study start.
Exclusion: Previous treatment and lack of efficacy or tolerability with metformin; Treatment with weight-lowering agents; Medications with significant renal impact; Major medical or surgical event in the preceding 3 months; History of metabolic acidosis or lactic acidosis; Moderate to severe substance use disorder, other than caffein or nicotine use disorder; Clinical or laboratory evidence of uncompensated cardiovascular, endocrine, haematological, hepatic, renal, or pulmonary disease; History or diagnosis of Type 1 Diabetes (T1D) or Type 2 Diabetes (TD2) or fasting blood work, HbA1c > 6.5%; Females who are nursing, currently pregnant, or have a positive pregnancy test; Acute suicidal risk.