GPs could help identify people who will end up claiming benefits for mental health issues three years before they give up work, research has suggested.
Before quitting work people suffering from mental distress visit their GPs far more regularly.
Data from thousands of people was examined by experts and it showed that doctors never signed people off work inappropriately.
But they did find a high number of consultations between GPs and those patients who eventually went on to claim incapacity benefit for mental health problems.
The number claiming incapacity benefit and severe disablement allowance has increased by more than 300% in the past 30 years in the UK, the study said.
The annual cost to the UK economy stands at more than £100bn.
Writing online in the British Medical Journal (BMJ), experts from the universities of Manchester, Glasgow and Stirling said: "Much current policy is aimed at getting people who are on long-term benefit back to work.
"It might, however, be more effective to focus on keeping those vulnerable to becoming dependent on benefit in work, rather than getting them back into work after a long period of absence from the workplace.
"GPs are well placed to identify people who are vulnerable to becoming dependent on benefit up to three years before this occurs by identifying frequent consulters with emotional distress."
"So now GPs have to understand the benefits system as well as everything else – well, they will be unique if they do! But then general practice is used to meeting impossible demands, realistically GPs have enough to do and as fast as benefits criteria would be learned they would change again" – Name and address withheld