'Mental illness more potent killer than heavy smoking'

Serious mental illness reduces life expectancy by 10-20 years - a loss of years that is equivalent to or worse than that caused by heavy smoking, a research has showed.

"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," said Seena Fazel from Oxford University.

The researchers looked 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.

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 was between 9-20 years, it is 10-20 years for schizophrenia, between 9-24 years for drug and alcohol abuse, and around 7-11 years for recurrent depression.

The loss of years among heavy smokers was 8-10 years, they found.

"High-risk behaviours are common in psychiatric patients, especially drug and alcohol abuse, and they are more likely to die by suicide," Fazel said.

"The stigma surrounding mental health may mean people aren't treated as well for physical health problems when they do see a doctor," he added.

The study appeared in the journal World Psychiatry.