Councils spend just 1% of their budget on preventing mental health problems, a charity has said.
Mind said the battle to prevent poor health was also undermined by the fact councils file the spend under "miscellaneous".
Its Freedom of Information inquiries to 152 local authorities discovered that some will spend nothing on preventing mental health problems this year.
This is despite the fact councils' remit clearly states they must run programmes to prevent both physical and mental ill health.
While local authorities spend millions of pounds on physical health programmes, Mind said most areas of the country spend "close to nothing" on preventing mental health problems.
Mind's "conservative" estimates suggest mental health problems cost the NHS and social care services £21 billion a year.
An extra £30 billion is lost in economic output.
Paul Farmer, chief executive of Mind, said: "Our research shows that the current spend on public mental health initiatives is negligible.
"The fact that local authorities' public health teams are allowed to file mental health under 'miscellaneous' when reporting on it perhaps explains why.
"It sends a message that mental health is not seen as important and not a priority for investment.
"It is not acceptable that such a small amount of the public health purse goes on preventing mental health problems.
"One in four people will experience a mental health problem every year, yet so much of this could be prevented by targeted programmes aimed at groups we know to be at risk, such as pregnant women, people who are isolated, or those living with a long-term physical health problem."
Some 131 councils responded to the FoI request from Mind.
Rough calculations show that just under £40 million is expected to be spent in 2015/16 on preventing mental health issues, compared to £664 million on sexual health, £160 million on stop-smoking programmes and £111 million on tackling obesity.
Mind said 10 local authorities will spend nothing in their 2015/16 budget on public mental health.
The charity declined to say which they were.
A Department of Health spokeswoman said: "This is not the full picture for preventative mental health care in this country.
"NHS funding for mental health increased to £11.7 billion in 2014/15 -- this money is helping more people than ever receive talking therapies, which have helped hundreds of thousands reach recovery and manage their conditions.
"That money is being spent alongside local authorities helping to keep their communities well."