Some mental health care, such as out-of-hours appointments, alcohol and crisis services, are being denied to those over 65.

The report found an unjustified 'reluctance' to accept referrals for over 65s or for those with dementia.

Despite the fact that over 65s make up a quarter of mental health inpatient admissions, four out of the six mental health trusts in the study made decisions based on age.

There needs to be a fundamental shift towards providing care based on a person's clinical need rather than their age

The research suggests that government targets often put older people's services at a low priority, combined with a lack of resources to deal with age-appropriate care.

Anna Walker, Healthcare Commission Chief Executive, said: 'Trusts are not always providing appropriate mental health services to the over 65s. There needs to be a fundamental shift towards providing care based on a person's clinical need rather than their age.'

Kate Jopling of Help the Aged said: 'It's shocking to think that, despite the need, older people are routinely being denied treatment for mental health services. The date on a birth certificate should not be the measure of whether or not someone receives the help they need for a mental health problem.'

The Commission is also concerned that there is limited national data available on the quality of specialist older people's mental health services, which means the scale of the problem is still not clear.

The number of people over 65 is set to increase by 15% by 2019 and the number of people with dementia to rise to one million by 2025.

Read the Heathcare Commission's report