Fewer than half of GPs have adequate training in mental health, figures have revealed.
Only 46% of trainee GPs have undertaken a training placement in a mental health setting, data obtained under the Freedom of Information Act by the charity Mind shows.
And once qualified, GPs are under no obligation to have any further training despite the fact an estimated one in three GP appointments is related to mental health, the charity said.
It also raised concerns about training for nurses who work in GP practices, saying a 2014 study found that 42% have had no mental health training at all.
The charity is urging the Government to ensure structured training is in place for trainee and qualified GPs and practice nurses.
Professor Maureen Baker, chairwoman of the Royal College of GPs, said: "Mental health is a key component of the RCGP training curriculum that all GP trainees must follow and demonstrate their competence in before they can practise independently as family doctors in the UK.
"We have been making the case for some time that specialist GP training should be extended from three to four years in order to focus more time on mental health and child health, reflecting the changing GP caseload and the increasing number of patients who are presenting with mental health issues.
"We hope that today's call from Mind will help strengthen our case."