Legal & General has revealed that mental health issues are the cause of nearly 20% of individual income protection (IP) claims it receives and is calling for government focus on mental health in the workplace.
The number of mental health claims nearly double that of cancer, which accounts for 12%, the insurer's results showed.
The average age at which customers typically claim for income protection due to mental health issues is just 41.
The insurer highlighted there is a gender bias - 59% of the claims made were made by women compared to two fifths (41%) by men.
Mark Holweger, managing director, intermediated at Legal & General Insurance said: "Mental health in the workplace is an issue that cannot remain in the shadows any longer. It is now the largest cause of the income protection claims we receive from people of working age who are unable to work for periods of time due to stress, anxiety, depression or other forms of mental illness."
Mental health is being debated in parliament, with care minister Norman Lamb looking to give more rights to people with learning disabilities, autism and mental health conditions.
Legal & General said it is equally important that mental health at work is considered and included as part of the wider mental health debate.
Holweger added:"We need to re-frame the debate around mental health in the workplace in order to raise greater awareness in this area. According to the Mental Health Foundation, mental health issues now account for 15% of the UK's overall disease burden.
"Addressing some of the underlying issues related to mental health in the workplace could make a significant impact in terms of reducing that burden on employees, their families and their employers."
