Medications used for high blood pressure, diabetes and cholesterol may also provide significant benefit to people with serious mental illness (SMI), say researchers at University College London.

The new study suggests the widely used drugs may potentially  benefit those with conditions such as schizophrenia, bipolar disorder or non-affective psychosis.

Results from the large cohort study appear in JAMA Psychiatry.

In the study, researchers assessed the health data records of 142,691 patients with SMI in Sweden. Scientists focused on those patients who had either been prescribed medications for high cholesterol, high blood pressure or for those with diabetes.

Investigators tracked the use of hydroxylmethyl glutaryl coenzyme A reductase inhibitors (HMG-CoA RIs) – commonly known as statins – used to lower cholesterol and reduce heart disease. They also reviewed utilization of L-type calcium channel antagonists (LTCC) prescribed to reduce high blood pressure such as amlodipine (Norvasc) and diltiazem (Cardizem); and biguanides (such as Metformin) for treatment of diabetes.

Researchers from the Karolinska Institute in Sweden, and the University of Hong Kong, analyzed patients’ health records relating to self-harm and psychiatric hospitalization. They assessed whether these episodes occurred during a period when patients were taking the prescribed medication or in periods when they were not.

The study found that exposure to any of the study drugs was associated with reduced rates of psychiatric hospitalization compared with unexposed periods. Self-harm was reduced in patients with bipolar disorder and schizophrenia during exposure to all study drugs and in patients with non-affective psychosis taking L-type calcium channel antagonists.

Lead author Dr. Joseph Hayes (UCL Psychiatry), said, “Serious mental illnesses, including bipolar disorder, are associated with high levels of morbidity and are challenging to treat.

“Many widely used drugs, such as statins, have long been identified as having the potential for repurposing to benefit these disorders. This study is the first to use large population data sets to compare patient’s exposure to these commonly used drugs and the potential effects on people with serious mental illnesses.

“Our research provides additional evidence that exposure to HMG-CoA RIs, LTCC antagonists, and biguanides might lead to improved outcomes for individuals with SMI,” he said.

“Given these drugs are commonly used and well-known to doctors they should be further investigated as repurposed agents for psychiatric symptoms.”

Researchers said all the studied drugs are known to have an effect on the central nervous system. However, the mechanism of action is not well-understood. Investigators are hopeful that a clearer understanding of the association may lead to new drug development to benefit those with serious mental illness.

Hayes added, “All three studied drugs are globally licensed, commonly used, cheap, and relatively safe medications. They are therefore ideal candidates for repurposing.

“If substantiated, this study has considerable implications for clinical practice and drug development.”

The studied drugs’ effects on patients were independent of whether patients were on or off drugs aimed at treating their mental illness (such as antipsychotic medication or mood stabilizers).

Source: University College London/EurekAlert