METRIC

Background

Psychosis occurs when you perceive or interpret reality in a very different way from people around you. You might be said to 'lose touch' with reality. The most common types of psychotic experiences are hallucinations, delusions and disorganised thinking and speech. Many people in the UK experience these symptoms, which often start when people are young. Most people are started on antipsychotic medication to help with their symptoms. However, these drugs cause a lot of weight gain, which can cause other problems in the future, such as heart disease or diabetes. It also has an impact on how people feel about themselves. Importantly, it may make people want to stop their antipsychotic treatment.

Metformin is a drug that has been used for over 60 years in the treatment of diabetes. Small studies suggest that it might stop some of the weight gain caused by antipsychotics and prevent diabetes. This study will look at whether metformin can stop, or reduce, weight gain for people taking antipsychotics in their first episode of psychosis.

Trial Summary

The study will involve 340 people who have psychosis for the first time and have started their antipsychotic medication no longer than a month ago. The study will take place in approximately 15-25 UK mental health services.

Patients will be randomly split into two groups. One group will be asked to take metformin for a year. The other group will be asked to take a placebo. A placebo - also known as a “dummy” or “sham” drug - doesn’t contain an active treatment. Patients and their doctors will not be able to tell which drug each patient is taking, until all patients have finished the trial. This is important so the true effect of metformin can be measured.

Patients will be seen by their mental health team every 3-6 months while taking the drug and for up to 6 months afterwards. The team will measure weight, mental health symptoms and how people feel in general about their health. Patients will also be asked if they have been to other services about their psychosis or weight. The risks of metformin are low but some blood tests will be taken to make sure that taking the drug is not causing any side effects.

Health professionals, patients and their carers involved in the trial will be asked what they think about using metformin to help with weight gain caused by antipsychotics and if there is anything that affects how closely involved they are with the trial. The team will also measure how often patients took their trial medication as prescribed and ask if anything helped or prevented them from taking their medication.

Patient involvement

A group of patients who had put on weight after starting antipsychotic treatment were asked what was important to them. They said that they would want enough information and support to take part in a trial. They also said they want to be asked how they are feeling, and to know that any possible side effects are checked. The patients also helped to work out the best way to ask these questions, and what would make it easier for them to take part in a trial like this.

Dissemination

The results will be reported in medical journals and presented at scientific meetings in the UK or abroad. The team will have input into clinical guidelines. Patients will help to write reports that are easy to read by patients as well as professionals. Posts will be shared on social media and through the trial website so that people will be able to hear about the results.