Common heart and diabetes pills taken by millions of people could be powerful treatments for psychiatric disorders, researchers have found.
Scientists at University College London said the cheap drugs could be repurposed to help people with schizophrenia or bipolar disorder, for whom there are few effective drugs.
Experts greeted the breakthrough as ‘remarkable’.
Cholesterol-busting statins, blood pressure pills called calcium channel blockers, and diabetes drugs such as metformin were each found to reduce the chance of someone with a severe psychiatric disorder being admitted to hospital because of their illness.
People taking the drugs were also shown to be far less likely to self-harm.
Common heart and diabetes pills, such as statins, taken by millions of people, could be powerful treatments for psychiatric disorders, researchers have found
An estimated 2.4million people in the UK have bipolar disorder, in which someone’s mood regularly swings dramatically from euphoria to depression.
Some 220,000 are being treated in Britain at any one time for schizophrenia – a severe condition characterised by delusions, hallucinations, and difficulties in understanding reality.
The researchers, whose results are published in the JAMA Psychiatry medical journal, assessed the health records of 140,000 patients treated for these mental illnesses in Sweden between 2005 and 2016.
They found that those who also took statins, calcium channel blockers or metformin were far less likely to end up in hospital as a result of their psychiatric problems.
People with schizophrenia were 25 per cent less likely to be hospitalised if they took statins, 20 per cent less likely if they took calcium blockers and 27 per cent less likely if they took metformin.
Those with bipolar were 14 per cent less likely to be hospitalised if they took statins, 8 per cent for calcium blockers and 20 per cent if they were on metformin.
The impact on self-harming was similar.
Study leader Dr Joseph Hayes of UCL, who carried out his research alongside the Karolinska Insitute in Sweden and the University of Hong Kong, said: ‘Serious mental illnesses, including bipolar disorder, 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.
‘Given these drugs are commonly used and well-known to doctors they should be further investigated as repurposed agents for psychiatric symptoms.’
The researchers are not sure exactly how the drugs minimise psychiatric problems – but they are all known to have an impact on the brain and the hormonal system, which may play a role.
Statins, for example, reduce inflammation throughout the body. If they also reduce inflammation in key parts of the brain, this could have an antipsychotic effect.
Dr Hayes said: ‘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.’
Experts have greeted the findings with enthusiasm.
Dr Derek Tracy, Royal College of Psychiatrists, said: ‘The often limited effectiveness of existing medication treatments for schizophrenia are well known, as are their side effects.
‘These remarkable results suggest that an entirely new class of medication – at least new in terms of mental health – may offer benefits.
‘Given the burden of schizophrenia, these results pave the way for further testing of the impact of statins, ideally using a scientific randomised controlled test.’
Professor Guy Goodwin, of the University of Oxford, said: ‘The use of big data to examine real world drug effects is a very exciting recent development.
‘The finding is practically important and theoretically very interesting.
‘Serendipity has served psychiatry well in the past and it appears set to do so again.’
And Dr James MacCabe, of King’s College London’s Institute of Psychiatry, Psychology & Neuroscience, said: ‘These findings are very compelling.
‘There is a misconception that randomised controlled trials are the only form of evidence that can be trusted, but they are of relatively short duration and small size.
‘By studying large populations over a long time in this way, one can detect effects on rare events, such as hospital admissions, that would be missed by clinical trials.’