Metformin for Antipsychotic-induced Weight Gain in Adults With Intellectual Disability

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.

NCT Number	NCT05744479
Lead Sponsor	Centre for Addiction and Mental Health
Conditions	Intellectual Disability, Developmental Disability, Obesity
Enrollment	100 participants
Start Date	2023-02-28
Primary Completion	2027-03-01 (estimated)
Study Completion	2027-03-01 (estimated)
Updated on ClinicalTrials.gov	2026-03-31