Research into brain disorders under threat as drug firms pull out

A decision by leading drug companies to pull out abruptly from research into brain disorders such as depression and schizophrenia leaves families without hope and will have a huge financial impact on society, senior scientists are warning.

Recent announcements by companies such as UK-based GlaxoSmithKline and AstraZeneca that they no longer intend to research new antidepressant drugs has effectively marked an end to the Prozac era, when leading drug companies vied to produce rival blockbuster pills that would be prescribed by GPs to millions of people with mild to moderate depression.

GSK's chief executive, Andrew Witty, denied last year that the controversy that broke around such pills – including its own Seroxat, which was said to increase the risk of suicidal thoughts in young people – was a factor in the decision.

He said they were some of the most expensive drugs to research, which could fail in late-stage trials.

Neuroscientists including David Nutt, professor of neuropsychopharmacology at Imperial College London, and Guy Goodwin, professor of psychiatry at Oxford University, are concerned that new treatments will dry up. They are the authors of a report for the European College of Neuropsychopharmacology (ECNP) published on Tuesday, which calls for urgent action to tackle the collapse of funding into research and medicines for brain disorders.

"What we have forgotten, and must not forget, is if we stop this research we will have a dead space of 20 to 30 years before we can re-tool again," said Nutt.

More than a quarter of the European Union population suffers from one or more neurological disorders every year, they say, which is a huge burden on health services and economies as people stay away from work. Their report says that throughout Europe, brain diseases are responsible for the loss of 23% of years of healthy life and 50% of years of disability – at a total cost of £237bn a year.

"Despite the public health imperative, not only has EU research funding remained very low, but – even worse – big pharma is increasingly coming to see research into better neuropsychiatric drug targets as economically non-viable," said Nutt.

Charities and public bodies leave the financing of drug treatments for mental disorders to the drug companies, the scientists say. If the industry is not researching the causes of depression or schizophrenia in order to find new drugs, scientists will not be able to advance their knowledge.

"We have a pretty primitive understanding of how the brain works in comparison to other systems," said Nutt.

The scientists hope they can persuade drug companies to share the information they already have, and that by putting details of their research and unused potential drug discoveries into a "medicines chest", scientists will be able to investigate and learn from. Some companies may be willing to take part, said Nutt.

"The issue that most comes up is about litigation – companies' concern that they could be sued 30 years down the line if an adverse effect emerged. We're thinking the ECNP could perhaps provide the insurance cover."

There are a number of reasons why companies are leaving the field, according to the report. Medicines for brain disorders take longer to develop than for other conditions – on average, 13 years – and there is a high failure rate.

Only one anti-depressant, Agomelatine, has been licensed in the last 10 years, compared with 10 new drugs for epilepsy. Companies are also increasingly fearful of lawsuits, as patients pursue them through the courts over the adverse effects of medicines.

Nutt, who was appointed to a government inquiry into the safety of Seroxat in 2003 but (with others) had to withdraw because of previous financial links to GSK, denied there were serious issues with antidepressants.

"All drugs have side-effects. The risk-benefit analysis of antidepressants is overwhelmingly positive," he said.

He and Goodwin contrast the funding available in cancer treatment, much of which is provided in Britain by the charity Cancer Research UK. Enduring stigma around mental illness means that people are less willing to contribute to mental health research than to cancer research, they say. It is also easier to mount studies of cancer drugs – in advanced cancers, trials leading to a licence for a new medicine can be run in a few hundred patients. Trials for new drugs for brain disorders have to involve thousands to ensure safety and efficacy in people who may be prescribed them by their GP.