Half of all people with mental health problems are living below the poverty line, according to research by the charity Mind.
Three quarters of the 900 people surveyed regularly avoid opening bills and admit to feeling confused about their finances.
People with mental health problems are three times more likely to be in debt than the general population. Three quarters of those participating in Mind's Still in the Red survey said their illness had made their debt worse.
The charity is urging people to seek help from its free Money and Mental Health guidebook available in GP surgeries, Citizens Advice Bureaus and online.