Metformin for Mind and Metabolism

Metformin is a medication originally derived from French Lilac which has been used to treat diabetes for over 50 years. The aim of this study is to see whether metformin can improve mood and memory in people who have depression and obesity. We will recruit 30 adults who feel depressed despite currently taking an antidepressant medication and who also have a large waist measurement (more than 88cm for women and 102cm for men). The study will last for 12 weeks. Participants will be randomized to either metformin 1000mg twice per day with food or placebo. At the beginning and the end of the study mood will be rated by self-report and by the doctor’s impression. Memory will be measured using a series of computer based tests, similar to playing simple computer games. The hope is that metformin will help obese adults with depression by reducing levels of the hormone insulin as well as markers of inflammation, within the brain, thereby improving mood.