Originally posted in the HSJ blog Leadership in Mental Health,  9 February 2012

People with long-term physical conditions are the most frequent users of the NHS. Long-term physical illnesses affect some 30 per cent of the population of England, or some 15 million people. Mental health conditions, meanwhile, affect about 10 million of us. What is less widely acknowledged, and certainly less well managed, is the overlap between those two groups and the massive cost to the NHS of failing to treat mental and physical illness together among those who are living with both.

A report published this week by The King’s Fund and Centre for Mental Health sets out just how big a cost the NHS is paying for the artificial separation of physical and mental health among the 4.6 million people with a long-term illness that co-exists with depression, anxiety or dementia.

The report calculates that the excess cost of treating long-term conditions among this group is at least £8bn a year to the NHS alone. This is because for each person with a mental health condition alongside their physical illness the costs of treating the latter are 45 per cent higher than for someone with the physical condition alone.

Depression and anxiety are significantly more common among people with a range of long-term physical illnesses: depression is at least twice as common among those with cardiovascular diseases and those with diabetes, and it is extremely common among those with arthritis. People with COPD, meanwhile, are 10 times more likely than average to have panic disorder.

Outcomes from cardiovascular care are poorer for patients with co-morbid mental health problems, even after taking severity of cardiovascular disease and patient age into account. Studies have shown that cardiovascular patients with depression experience 50 per cent more acute exacerbations per year and have higher mortality rates. One study found that depression increases mortality rates after heart attack by 3.5 times while another found that patients with chronic heart failure are eight times more likely to die within 30 months if they have depression.

People with diabetes who also have co-morbid mental health problems, meanwhile, are at increased risk of poorer health outcomes and premature mortality. Co-morbid mental health problems are associated with poorer glycaemic control, more diabetic complications and lower medication adherence, and children with Type I diabetes are more likely to suffer from retinal damage if they also have depression.

The reasons for this excess mortality, morbidity and cost are complex but they include the reduced ability people with a mental health condition may have to manage their physical illness and a greater likelihood of health-damaging behaviour such as smoking. It should not, however, be seen as an inevitable cost.

While not all of the £8bn can be saved, improved integration can have a dramatic effect. The RAID liaison psychiatry service in Birmingham City Hospital, now cited in the NHS Operating Framework, saves the NHS some £3.5m a year in reduced hospital bed use. And outside hospital, collaborative care arrangements between primary care and mental health services, including psychological therapies, can improve the quality of support people receive at little extra cost to the NHS.

Improving the management of co-morbidity has already been identified by The King’s Fund as one of the top ten priorities for clinical commissioning groups to address as they take shape and begin to assume their new responsibilities. In taking on this challenge, commissioners will not just be able to achieve substantial cost savings but will also bring about dramatic improvements in the lives of some of the most vulnerable people in their communities.