It is well-established that individuals with bipolar disorder and schizophrenia live much shorter lives than the rest of the population, dying an estimated 10 to 25 years younger, depending on the nation where they reside.Now, new evidence from an analysis of nearly 40,000 health records in the United Kingdom from 2000 to 2014 indicates the mortality gap between the two populations is growing larger.
Overall, death rates from all causes declined since 2000 both for the general population and for individuals with bipolar and schizophrenia. However, since the mid-2000s, death rates for the general population have fallen further and faster than for individuals with one of the two diseases, according to the new study.
"This suggests . . . health inequalities are growing," Joseph F. Hayes and colleagues write in the British Journal of Psychiatry online. "This is despite a greater focus on this problem at a national and international level, in specialist, primary care and public health settings." Smoking cessation programs, for instance, have been less effective among people with serious mental illness than the rest of the population.
Overall, the death rate from all causes was 1.77 times greater in 2014 for individuals with bipolar disorder and 2.08 times greater for those with schizophrenia, even after adjusting for risk factors such as smoking, high cholesterol, high blood pressure, obesity, diabetes and sociodemographic factors.
Three health indicators were found central to the mortality gap for serious mental illness: rates of cardiovascular disease, suicide and self-harm.
For example, in people aged 16-50, the death rate from cardiovascular disease was 2.5 times higher for individuals with schizophrenia than for those the same age in the general population. Despite the heightened risk, they were found to be infrequently diagnosed with heart disease prior to death, and women were less likely to be diagnosed than men.
Suicide and Self-Harm Risks
While evidence indicates heart disease is the leading cause of death in individuals with serious mental illness, the relative risk of dying from suicide is even higher, the authors found.
Individuals with bipolar disorder were 12.66 times more likely to die of suicide than the comparison group in the general population; those with schizophrenia were 7.21 times more likely to kill themselves than the comparison group. In both conditions, the disparity was found irrespective of gender, age or time of year.
Self-harm - a significant risk factor for suicide - also was found much more prevalent among those with the two diseases, especially those under the age of 50. For all ages, the risk of self-harm was 25 times higher for individuals with bipolar disorder and 22 times higher for those with schizophrenia. In the 16-50 age cohort, the risk of suicide was 56 times higher for individuals with bipolar and 52 times higher for those with schizophrenia.
The findings are based on analysis of anonymized primary care health records of every individual aged 16 or older with a diagnosis of bipolar or schizophrenia in the United Kingdom from 2000 to 2014. Death rates from serious mental illness in the United States are worse, with life expectancy widely reported to be 25 years shorter than in the general population.
The authors speculated closure of psychiatric beds may be one of the sources of the growing mortality gap.
"Although deinstitutionalization in the UK has been a success in terms of integrating people into wider society, it has been argued that there is now too little support for people living with bipolar disorder and schizophrenia in the community, and this may be reflected in mortality rates," they write.