June 22, 2009 -- The mortality rate among schizophrenics is four times higher than in the general population, with suicide being the No. 1 cause of death, followed by cancer, according to a new study.
Deaths from cancer among women with schizophrenia were twice that of the general population, based on standardized mortality data. Deaths from breast cancer were almost three times higher than expected. The study appears in the Aug. 1 issue of Cancer.
Lung cancer death rates among male schizophrenics were about twice that of men in the general population, but the overall risk of dying from cancer was not significantly different between the two groups.
It has long been recognized that schizophrenia is associated with a higher risk for suicide and death from heart disease, but the investigation is one of the largest and longest follow-up studies to explore cancer deaths in schizophrenic patients.
Schizophrenics are more likely to smoke than the general population, and are less likely to have comprehensive medical care.
They may also be more likely to have a delayed cancer diagnosis, have poorer access to treatment, or be noncompliant with treatment, lead investigator Frederic Limosin, MD, PhD, of France's University of Reims tells WebMD.
"Cancer is the second leading cause of death in schizophrenic patients," Limosin says. "Later diagnosis and treatment issues may explain this, but there may also be something else going on."
Schizophrenia Linked to Early Death
The study included 3,470 French patients with schizophrenia followed for 11 years between 1993 and 2004.
Patients ranged in age from 18 to 64 at study entry. About two-thirds were between the ages of 39 and 64 at enrollment.
During the follow-up, 476 patients (14%) died -- a death rate that was fourfold higher than in the age-matched general population.
The study revealed that:
- The death rate from suicide was more than 15 times higher than that of the general population, Limosin says.
- A total of 143 patients committed suicide (4.2%), compared to 74 who died from cancer (2.2%), and 70 from cardiovascular disease (2%).
- Half of the malignancy-related deaths in men in the study were attributed to lung cancer, and about 40% of the cancer deaths in women were from breast cancer.
Schizophrenia Treatment and Breast Cancer
Although the excess in breast cancer deaths could be explained by delayed diagnosis and poorer access to or compliance with treatment, schizophrenia expert Donald C. Goff, MD, says there may be more going on.
Goff cites a 2002 study, which suggested a link between the use of dopamine-blocking drugs, including the antipsychotics used to treat schizophrenia, and an increased risk for breast cancer.
"This study raised questions about whether antipsychotics cause breast cancer," Goff tells WebMD. "The conclusion at the time was that there wasn't much evidence to support this."
Goff, who directs the schizophrenia program at Massachusetts General Hospital, says it has long been recognized that patients with schizophrenia are at risk for early death, but efforts to address this have generally targeted suicide prevention, smoking cessation, and heart disease.
Gregory Dalack, MD, tells WebMD that the psychiatric community is increasingly recognizing the need to integrate primary care interventions into psychiatric practice.
Dalack is interim chair of the department of psychiatry at the University of Michigan Health System.
"These patients are vulnerable," he says. "They are high risk, and yet we are not doing the basic things for them that we do for other high-risk populations."
Because so many mentally ill patients do not have primary care doctors, psychiatrists are increasingly doing things like weighing patients, taking waist circumference measurements, and discussing smoking cessation and exercise, he says.
"But it is hard to talk about exercise with a patient who is worried about paying the rent or putting food on the table," he says, adding that a focus of health care reform should be better integration of primary and mental health care.