A study that examined trends over 20 years in a large Canadian population revealed that people with schizophrenia were three times more likely to die than people without it. Those with the disorder were also found to have a lower life expectancy.

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Researchers have found a large life expectancy gap between people with schizophrenia and those without it.

Writing in the Canadian Medical Association Journal, researchers – led by Dr. Paul Kurdyak, of the Centre for Addiction and Mental Health and the Institute for Clinical Evaluative Sciences, both in Ontario, Canada – call for greater efforts to reduce the gap.

Schizophrenia is a severe, long-term, disabling mental disorder that typically starts in late adolescence or early adulthood. It affects around 1.1 percent of adults in the United States.

The disorder disrupts perception, thinking, emotions, and behavior, often making it very difficult to hold down a job, have relationships, and deal with everyday life.

Although there is currently no cure for schizophrenia, there are treatments that can help patients to manage their symptoms and have a productive, independent life.

Dr. Kurdyak and colleagues decided to conduct their study because previous analyses have tended to use methods of identifying people with schizophrenia that might distort the figures.

“It’s clear that there is not enough evidence to support what we should be doing,” says Dr. Kurdyak.

For example, studies have previously used hospital admissions as a way of identifying people with schizophrenia, which can lead to bias toward more severe illness as it “misses individuals managed in ambulatory settings.”

Also, other studies have used severe mental illness categories “that include disorders other than schizophrenia.”

However, in Ontario, the way that records are maintained allowed the researchers to accurately identify “every resident within the population who had a diagnosis of schizophrenia.”

For their analysis, the team examined records for more than 1.6 million deaths that occurred in Ontario in the 20-year period between 1993 and 2012.

After excluding people who died before the age of 15 and a small number for whom cause of death was not available, the researchers included 1,621,251 deaths in the analysis. Of these, 31,349 (1.9 percent) occurred in people with schizophrenia.

The analysis showed that, over the 20-year period, “individuals with schizophrenia experienced three times greater mortality rates, compared with the general population, even after adjustment for sociodemographic factors.”

“Those with schizophrenia also died younger and lost more potential years of life,” note the authors.

While average age of death for people with schizophrenia did go up between 1993 and 2012 (from 64.7 to 67.4 years) – as it did in the general population (from 73.3 to 76.7 years) – there remained a large life expectancy gap of at least 8 years between the two groups.

Dr. Kurdyak says that as well as revealing “astonishingly high mortality rates” for people with schizophrenia, their findings highlight an “equity issue.”

He and his colleagues suggest that people with schizophrenia have not benefited from the reduction in cardiovascular deaths observed in the general population.

The study authors suggest that the higher risk of death in people with schizophrenia might be due to inadequate access to healthcare and lifestyle factors such as smoking, higher rates of alcohol consumption, lack of physical activity, and poor diet.

The team concludes that “more effort is required to reduce the considerable disparity in both mortality and illness burden” between people with schizophrenia and the general population.

In a linked commentary, Dr. Philip Ward – of the University of New South Wales Sydney in Australia – says, “A gap in life expectancy of this size for any other group of patients might reasonably be expected to lead to correspondingly substantial public health action to redress the health inequality. However, this does not appear to be the case for people with schizophrenia.”

He suggests that tactics to help people with schizophrenia to give up smoking, improve diet, and prevent weight gain (which is a common side effect of the drugs) could help to reduce the gap in life expectancy.

Dr. Ward notes that there are many ways to do this and they all need to be trialled, giving examples ranging from “embedding specialist medical clinics within mental health settings,” to helping and empowering people with schizophrenia “to become assertive seekers of effective treatment for chronic illness.”

He also urges that if there is to be “system-wide change” in healthcare, then those responsible for overseeing health systems need to report regularly on the physical health of people with schizophrenia.

The complex needs of individuals with schizophrenia and comorbid medical conditions create a tremendous challenge to providers and healthcare systems more broadly.”

Dr. Paul Kurdyak