Mental health problems are very common. Estimates from research studies suggest that one in four people in the UK experience a diagnosable mental health problem at some point during their life. Depression and anxiety disorders are the most common forms of mental health problems, and evidence indicates that around a third of people with depression and half of people with anxiety disorders do not receive any support or treatment from health services.

Mental heath was one of the previous government’s top three clinical priorities, alongside cancer and heart disease. Since 2001-02, real terms investment in adult mental health services has increased by 44 per cent. Over 700 new community mental health teams have been created, and numbers of consultant psychiatrists and mental health nurses have increased by 64 per cent and 21 per cent respectively since 1997.

Most people with mental health problems are supported solely by GPs and other professionals working in primary care. Around 10 per cent of patients with mental health problems are referred on to specialist teams.

In spite of the high profile given to mental health by the previous government, some challenges have proven difficult to address. For example, waiting times for psychological therapies remain high. This is currently being tackled through the Improving Access to Psychological Therapies programme, launched in 2007.

Dementia currently accounts for 66 per cent of all mental health service costs, and is an issue of increasing concern. The King’s Fund report Paying the Price: The cost of mental health care in England in 2026 estimated that the number of people with dementia will increase by 62 per cent from 2007 to 2026. The Department of Health's National Dementia Strategy, launched in February 2009, aims to see diagnoses being made at an earlier stage of the illness, and to improve the quality of care provided.

For those people with severe mental illnesses such as schizophrenia, the last 25 years have witnessed a major transformation in the way services are delivered, with care shifting from large inpatient institutions to community-based teams. The NHS Plan in 2000 introduced a range of new service types designed to meet the needs of people with mental health problems living in the community.

After several years of debate, the 2007 Mental Health Act introduced a number of reforms to the laws governing when and how a person can be detained for assessment and treatment of mental health problems. The most controversial element of this is the introduction of Community Treatment Orders, under which patients can be compelled to continue taking medication after discharge from hospital.

The previous government launched a new mental health strategy in 2009, known as 'New Horizons'. This marked a shift in direction, with greater emphasis being placed on promoting positive mental health and well-being across the whole population, and preventing mental health problems from developing. The current government has not yet released details on its mental health strategy, but the focus on prevention and promotion is expected to remain.

The costs to the NHS of mental ill health are forecast to rise over the coming years. The King’s Fund report Paying the Price: The cost of mental health care in England to 2026 estimated that expenditure will reach £47 billion a year by 2026, compared with £22.5bn in 2007. This is due largely to a predicted rise in the number of people with dementia.

A key challenge for mental health services over the coming years will be to deliver better value for money without sacrificing quality of care. The King's Fund's Mental Health in a Cold Climate project is exploring this issue, and will report later in 2010.