Some mental illnesses may be more deadly than heavy smoking, according to Oxford University researchers.
They found that people with bipolar disorder and schizophrenia were,on average,likely to die one to two decades sooner, than those without those diagnoses.
Drug and alcohol abuse cut the lifespan by nine to 24 years, and people with recurrent depression were likely to die seven to eleven years earlier.
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 behaviors 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," she added.