Diabetes Prevention Program in Schizophrenia [DPPS]

Rationale: * From large international RCT studies, Type 2 Diabetes can be prevented / delayed for overweight, pre-diabetic individuals by making basic lifestyle changes (regular moderate exercise, healthy eating habits) and using metformin or other insulin resistance inhibitor. * Individuals with schizophrenia are in particular need of preventative intervention and conventional approaches do not match their needs. * Research has not examined how to facilitate lifestyle changes in the lives of individuals with schizophrenia. We need to… * Develop and evaluate innovative diabetes prevention strategies tailored to meet the needs of individuals with schizophrenia. * Research how to make it work for pre-diabetic individuals being treated for schizophrenia. The effectiveness of the novel intervention will be tested using a prospective, randomized, controlled clinical trial. A multi-factorial design enables a 2 x 2 analysis of the independent effects of three interventions - a tailored lifestyle modification program, metformin, and the standard conventional intervention. There is no anticipated interaction effect between metformin and lifestyle interventions. Clients currently treated for schizophrenia at a community outpatient clinic will be screened for diabetes, and those who fulfill the inclusion criteria, and give written consent, following a three week run-in period, will be randomized to one of four groups to receive either: the experimental intervention with placebo, the experimental intervention with metformin or the conventional intervention with placebo or conventional intervention with metformin.