Life expectancy is a statistical measure of the number of years remaining in an individual’s life at a given age. This number is affected by various factors, many of which are health factors. One such statistic states that the life expectancy of heavy smokers is around eight to 10 years less than than that of non-smokers.

A group of scientists from the Department of Psychiatry at the University of Oxford found appalling results upon calculating the life expectancy of individuals with mental illnesses. The study, published in World Psychiatry, is an analysis of a host of prior research about the death risk of factors including drug and alcohol abuse, dementia, autism, learning disability and childhood behavioural disorders. In total, 20 papers that looked at 1.7 million people and over 250 000 deaths collectively, were examined.

“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 Dr Seena Fazel, of the Department of Psychiatry at Oxford University.

Researchers found that bipolar disorder caused the loss of between nine and 20 years, schizophrenia caused a loss of 10 to 20 years, and recurring depression caused the loss of seven to 11 years.

‘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. 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,” said Dr. Fazel.

As dismal as all these numbers seem, experts say that there is hope for the better, if certain changes are made. This emphasizes the need to ensure that individuals have straightforward access to healthcare, appropriate work opportunities and meaningful hobbies. 

With such strong evidence for the link between lower life expectancy and the morbidity of mental illness, governments, healthcare providers and researchers need to make mental illness a priority.