A new study has shown that bipolar disorders increase the risk of early death from a medical illness.
For the study, the researchers comprehensively reviewed 17 studies involving more than 331,000 patients.
They found that people with bipolar disorder have a higher mortality from natural causes compared to people in the general population of similar age and gender but without mental illness.
The various studies indicated that the risk was from 35 percent to 200 percent higher.
The risk is the same for men and women. The most common conditions leading to premature death were heart disease, respiratory diseases, stroke, and endocrine problems such as diabetes.
"The review of data gathered from large population studies suggests that having bipolar disorder is similar to being a smoker in terms of increasing a person's risk of early death," said Dr. Wayne Katon, a University of Washington (UW) professor of psychiatry.
People with bipolar disorder tend to have manic phases and depressed phases in their lives.
During mania, they might be too wound up to sleep, their thoughts might race, and they might have boundless energy. During depression, they might feel painfully sad, hopeless, and immobilized.
In the past, the higher premature death rate among people with bipolar disorder was attributed to a higher rate of suicide and accidents.
Katon said that more recently, researchers are finding that, while rates of suicides and accidents are indeed greater among those with bipolar disorder compared to the general population, they only partly account for the higher premature death rate.
Katon said that emerging evidence shows that the majority of early deaths among people with bipolar disorder come from medical conditions.
The study is published in the journal Psychiatric Services.