Finding new uses for diabetes drugs

Widely-used drugs for diabetes and heart conditions have potential for treating severe mental illness, a new study suggests. Patients who took these drugs needed fewer hospital admissions for mental illness compared to those who did not.

Instead of testing the drugs in trials, researchers analysed medical records of more than 140,000 people in Sweden, who had schizophrenia, bipolar disorder or other severe mental illnesses.

They then looked at how many times the patient was admitted to a psychiatric hospital when they were taking statins (anti-cholesterol drugs), blood pressure drugs or metformin, a diabetes drug, and when they were not. The number of times patients needed hospital treatment fell by up to a fifth, when they took these drugs, with a 10 to 20 per cent reduction in illness episodes when on the drugs.

The results, published in the journal JAMA Psychiatry, also showed a reduction in self-harm.

Statins may calm inflammation linked to mental health problems; blood pressure drugs may alter calcium signalling in the brain, which has been linked to bipolar disorder and schizophrenia; and metformin may alter mood.

CAUTION

Dr Joseph Hayes, one of the researchers, says that large clinical trials to test the drugs can give a final answer on whether these drugs can help patients with severe mental health disorders.

In the meantime, Dr Hayes cautions that people should not go out and get these drugs themselves without prescription.

The study is part of the trend of looking into widely-used and affordable drugs for other illnesses that can be repurposed for management of mental illness as well as other illnesses.

Repurposed drugs are medications that have already been proven to be safe, but are used to treat a different condition from what they were made for. They sometimes provide a cheaper alternative treatment.

Developing a new drug from scratch is a costly process that takes years. This is why drugs that are already in use are being studied to determine whether they can be used to treat or manage other diseases, especially those that are chronic.

While taking a statin for heart health could have a potential benefit for mental health, the researchers noted that the way the study was designed, could mean that the statins and other drugs could be a red herring.

Whereas a lot of studies compare one group of patients taking a drug with another group not taking it, this one compared the same patients at different stages of their life when they were either on the drug or not.

This could mean that when people are in a good place mentally and less likely to be admitted to hospital, they are also more likely to look after themselves and take other medications.

This is why the results need to be tested in clinical trials.