Serious mental illnesses reduce life expectancy by 10-20 years, an analysis by Oxford University psychiatrists has shown - a loss of years that's equivalent to or worse than that for heavy smoking.

Yet mental health has not seen the same public health priority, say the Oxford scientists, despite these stark figures and the similar prevalence of mental health problems.

1 in 4 people in the UK will experience some kind of mental health problem in the course of a year, it is estimated. Around 21% of British men and 19% of women smoke cigarettes.

The researchers say the figures should galvanise governments and health and social services to put a much higher priority on how mental health services can prevent early deaths.

The Oxford University researchers report their findings in the journal World Psychiatry. The study was funded by the Wellcome Trust.

The researchers searched for the best systematic reviews of clinical studies which reported mortality risk for a whole range of diagnoses - mental health problems, substance and alcohol abuse, dementia, autistic spectrum disorders, learning disability and childhood behavioural disorders. 20 review papers were identified, including over 1.7 million individuals and over 250,000 deaths.

They repeated searches for studies and reviews reporting life expectancy and risk of dying by suicide, and compared the results to the best data for heavy smoking.

The average reduction in life expectancy in people with bipolar disorder is between 9 and 20 years, it's 10-20 years for schizophrenia, between 9 and 24 years for drug and alcohol abuse, and around 7-11 years for recurrent depression.

The loss of years among heavy smokers is 8-10 years.

All diagnoses studied showed an increase in mortality risk, though the size of the risk varied greatly. Many had risks equivalent to or higher than heavy smoking (see table in notes for editors). Dr Seena Fazel of the Department of Psychiatry at Oxford University said: 'We found that many mental health diagnoses are associated with a drop in life expectancy as great as that associated with smoking 20 or more cigarettes a day.

'There are likely to be many reasons for this. High-risk behaviours are common in psychiatric patients, especially drug and alcohol abuse, and they are more likely to die by suicide. The stigma surrounding mental health may mean people aren't treated as well for physical health problems when they do see a doctor.'

One problem is the tendency to separate mental and physical illness, explains Dr Fazel. 'Many causes of mental health problems also have physical consequences and mental illness worsen the prognosis of a range of physical illnesses, especially heart disease, diabetes and cancer. Unfortunately, people with serious mental illnesses may not access healthcare effectively,' says Dr Fazel.

Dr Fazel is certain: 'All of this can be changed. There are effective drug and psychological treatments for mental health problems. We can improve mental health and social care provision. That means making sure people have straightforward access to health care, and appropriate jobs and meaningful daytime activities. It'll be challenging, but it can be done.'

He notes: 'Beyond that, psychiatrists have a particular responsibility as doctors to ensure that the physical health of their patients is not neglected. De-medicalization of psychiatric services mitigates against that.'

He adds: 'What we do need is for researchers, care providers and governments to make mental health a much higher priority for research and innovation. Smoking is recognised as a huge public health problem. There are effective ways to target smoking, and with political will and funding, rates of smoking-related deaths have started to decline. We now need a similar effort in mental health.'

Table of all-cause mortality for various mental health and other diagnoses as compared to general population and the mortality risk for heavy smoking. This summarises the best available evidence from reviews of research studies:

DiagnosisRisk of mortality compared with general populationRisk normalised to that for heavy smoking
Opioid users14.75.8
Amphetamine users6.22.4
Cocaine users6.0*2.4
Anorexia nervosa5.92.3
Disruptive behaviour disorder5.0**1.9
Methamphetamine use4.71.8
Acute and transient psychotic disorder4.71.8
Alcohol use disorder4.61.8
Personality disorder4.21.7
Intellectual disability (moderate to profound)2.81.1
Heavy smoking2.6**1.0
Schizophrenia2.51.0
Bipolar disorder2.2*0.8
Bulimia nervosa1.90.8
Eating disorder (not otherwise specified)1.90.8
Adults with childhood ADHD1.90.8
Depression1.60.6
Dysthymic disorder1.40.6
Co-morbid anxiety/depression1.40.6
Cannabis use1.2*,**0.5
* Mid-point of range; ** Mean value of male and female mortality

Statement from Mind commenting on this research

A research study carried out by Oxford University and funded by the Wellcome Trust has found that serious mental illnesses reduce life expectancy by 10-20 years, a loss of years equivalent or worse than that for heavy smoking. The meta-analysis, published tomorrow (Friday, 23 May) in the journal World Psychiatry, highlights the discrepancy between physical and mental health services. Geoff Heyes, Policy and Campaigns Manager at Mind, said:

"This new research adds to the significant body of evidence that people with mental health problems die younger than the general population. We know it is possible to live a long and healthy life with a mental health problem but under-funded and poorly integrated services are preventing people accessing a range of quality treatments to enable them to manage their both their physical and mental health.

"Campaigns such as Time to Change have helped reduce the stigma surrounding mental health problems, and people are becoming more willing to seek help sooner. However, when people with mental health problems do seek help, they can find it more difficult to access physical health services and have worse outcomes for physical health conditions, sometimes because health professionals write off their concerns about legitimate physical complaints as a symptom of their mental health condition.

"While smoking-cessation has been a public health priority and smoking related deaths have reduced in recent years, too little attention has been paid to evidence-based and targeted interventions to help people with mental health problems stop smoking. After all, 42% of all cigarettes smoked in England are by people with mental health problems.

"We urgently need to see mental health services given as much importance as physical health, and much better integration of mental and physical health services, so that people are treated as a whole and taken seriously."