Attenuation of antipsychotic induced weight gain in people with severe mental illness. Mental and Behavioural Disorders
Conditions
Interventions
Intervention: Film coated tablets of metformin XR, starting at 500 mg daily and titrating up to 2000 mg daily over a 6-week period, orally for a total of 26 weeks.
Control: Placebo - identical-lookin
Sponsors
University of York
Eligibility
Sex/Gender
All
Age
18 Years to 100 Years
Inclusion criteria
Inclusion criteria: Current key inclusion criteria as of 17/10/2025: 1. Clinical diagnosis of SMI (i.e. schizophrenia, schizoaffective disorder, bipolar affective disorder, psychosis, severe depression with psychosis) 2. Antipsychotic naive 3. Able to, and willing to provide informed consent 4.=/ >18 years of age 5. BMI=/ > 18.5 kg/m² 6. Taking antipsychotic medication for 18 years of age 5. BMI > 18.5 kg/m² 6. Taking antipsychotic medication for < 28 days
Exclusion criteria
Exclusion criteria: 1. BMI < 18.5 kg/m² 2. Known allergies or contra-indications to metformin or any part of the formulation of the placebo or investigational product 3. Diagnosis of type 1 or type 2 diabetes, or already taking metformin 4. Found to have HbA1c within diabetes range from blood tests 5. Prior diagnosis of a condition which is directly associated with obesity (self-reported) 6. Obesity induced by other endocrine disorder 7. Chronic kidney disease (eGFR < 30 mL/min) 8. Concomitant disease or condition (neurodegenerative disease, cognitive impairment) that investigators consider makes the patient unsuitable for trial participation 9. Taking weight-lowering therapy including: pramlintide, sibutramine, orlistat, zonisamide, topiramate or phentermine (or part of a clinical trial of such treatments) 10. Previous surgical treatment of obesity 11. Women who are pregnant or breast-feeding, or of childbearing age and not using contraceptives 12. Unable to provide informed consent, or lacking capacity
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in body weight, measured in kg at 6 months post randomisation. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Abdominal circumference measured using Seca 201 Ergonomic circumference measuring tape at baseline, 3 months, and 6 months. 2. Height measured using portable stadiometer at baseline, 3 months, and 6 months (this will be used to calculate BMI). 3. Blood pressure measured using OMRON blood pressure monitor at baseline, 3 months, and 6 months. 4. HbA1c measured using laboratory analysis at baseline and 6 months. 5. Lipid profile measured using laboratory analysis at baseline and 6 months. 6. Liver function tests (LFTs) using laboratory analysis at baseline and 3 months. 7. Renal function using laboratory analysis at baseline: 7.1. Complete blood count using laboratory analysis at baseline. 7.2. Serum B12 using laboratory analysis at baseline and if abnormal, will be repeated at 6 months. 7.3. Thyroid function using laboratory analysis at baseline. 7.4. Liver function using laboratory analysis at baseline and if abnormal, will be repeated at 6 months. 8. Health-related quality of life measured using EQ-5D-5L at baseline, 3 months, and 6 months. 9. Depressive symptoms measured using PHQ-9 at baseline, 3 months, and 6 months. 10. Anxiety symptoms using GAD-7 at baseline, 3 months, and 6 months. 11. Psychotic symptoms using BPRS at baseline, 3 months, and 6 months. 11.1. Mental health admissions - self reported at baseline, 3 months and 6 months. 11.2. Hospital admissions - self reported at baseline, 3 months and 6 months. 11.3. Physical activity - measured using IPAQ tool at baseline, 3 months and 6 months. 11.4. Diet - measured using questions from WHO STEPwise survey at baseline, 3 months and 6 months. 11.5. Tobacco use - measured using questions adapted from the tobacco section of the WHO STEPwise survey at baseline, 3 months and 6 months. 11.6. Drug use - measured using questions adapted from the tobacco section of the WHO STEPwise survey at baseline, 3 months and 6 months. 11.7. Sleep Quality - measured using the PSQI tool at baseline, 3 months and 6 months. | — |
Countries
Pakistan
Contacts
Public ContactKoralagamage Kavindu Appuhamy
Outcome results
None listed