Local authorities in England are spending "unacceptably low" amounts on mental health prevention services compared to physical health, a charity has warned.
Research by mental health charity Mind revealed local authorities, who took over responsibility for public health from Primary Care Trusts in April, intend to spend an average of 1.36% of the budget on mental health prevention this financial year.
The Freedom of Information requests found the national spend is estimated to be around £40 million, compared to £108m on anti-obesity campaigns, £160m on stop-smoking services and £671m on sexual health initiatives.
Of the 86 local authorities that responded, six have no specific spending plan for public mental health.
Although spending has increased by around 0.24% on last year, Paul Farmer, chief executive of Mind, said far more investment is needed.
He said: "Just like physical health, we all have mental health.
"Mind's findings show, however, that while local authorities are happy to spend on preventing physical health problems, their equivalent spending on mental health is unacceptably low.
"We need to invest in everyone's mental health, particularly for people who are more likely to become unwell such as younger people, pregnant women, people who are isolated, or those living with a long term physical health problem.
"With demand for mental health services increasing, anti-depressants on the up and more people accessing talking therapies, we are beginning to see the scale of the unmet need for mental health services in England.
"As a society, we must start looking at what we can do to help prevent people from developing mental health problems in the first place.
Prevention measures include awareness campaigns at schools, support groups for new mothers and training council housing staff and members of the local community in identifying warning signs.
A study by the Centre for Mental Health in 2010 estimated mental illness costs the UK economy as much as £100bn through cost of treatment, lost working days and benefits.
Mr Farmer added: "Local authorities need much clearer guidance and support on how best to tackle mental health problems.
"We want the next government to introduce a national strategy to ensure local authorities know what to do, and use their budgets to prevent mental health problems developing and reduce the number of people becoming unwell."
Labour mental health spokeswoman Luciana Berger said: "Mental health should be treated no differently to physical health but these findings are further evidence that mental health is clearly at a disadvantage when it comes to allocating funds.
"The Government is failing to honour its promise of treating mental health with the same importance and attention as physical health.
"David Cameron must urgently tackle the crisis in mental health services. Ministers must do more to ensure that services needed by people with mental illness are in place and patients get the help and support that they need."