Psychosis is a condition in which someone perceives reality differently from those around them. It may be described as “losing touch" with reality.
The most common types of psychotic experiences are hallucinations, delusions and disorganised thinking and speech.
Most patients are started on antipsychotic medication to help with their symptoms. However, these drugs can cause significant weight gain, which can lead to other problems in the future, such as heart disease or diabetes.
Weight gain can also negatively affect how people feel about themselves and may lead some people to stop their antipsychotic medication.
Metformin is a drug that has been used for over 60 years in the treatment of diabetes. Small studies suggest that it might reduce some of the weight gain caused by antipsychotic medication and help prevent diabetes.
Design and methods
The METRIC study aims to recruit 340 participants across 15–25 UK mental health services, who are experiencing psychosis for the first time and who haven’t used antipsychotic medication for more than four weeks.
Patients will be randomly split into two groups. One group will be asked to take metformin for a year, and the other group will be asked to take a placebo.
Patients will be seen by their mental health team every three months while taking the study medication and for up to six months afterwards.
The research team will measure weight, mental health symptoms, side effects, and the patients’ feelings about their overall health and well-being. Patients will also be asked about their use of other health services related to their psychosis or weight.
The team will also assess how frequently participants take their trial medication and explore factors that help or prevent adherence.
Also, health professionals and carers involved in the trial will be asked for their views on using metformin to manage antipsychotic-related weight gain and on aspects that influence engagement with the study.
If the trial shows that metformin makes a difference, Dr Paul French, Co-Lead of the study, feels that impact can be achieved quickly.
"We know that it can sometimes take an age for research to become a routine clinical intervention, but if this works, it has the potential to make a real difference for people with psychosis, because the intervention could quickly become embedded into clinical guidelines and practice, nationally and internationally."
The £3.029M study is led by Dr Paul French, Pennine Care NHS Foundation Trust, and Prof Richard Holt, University of Southampton, and is supported by Sheffield CTRU. It is funded by the NIHR’s Health Technology Assessment Programme.
For more info, please see the METRIC webpage.