People suffering from schizophrenia, bipolar disorder or serious depression are 2.6 times more likely to develop cancer than people without a serious mental disorder, according to new Johns Hopkins research.
The findings generate questions about whether patients with severe mental illness are receiving cancer screenings and other types of preventative care.
“The increased risk is definitely there, but we’re not entirely sure why,” says study leader Gail L. Daumit, M.D., M.H.S., an associate professor of medicine and psychiatry at the Johns Hopkins University School of Medicine.
“Are these people getting screened? Are they being treated? Something’s going on.”
In another study, published online last month in the journal Injury Prevention, Daumit found that patients with serious mental disorders were almost twice as likely to end up in a hospital’s emergency room or inpatient department suffering from an injury than the general population and about 4.5 times more likely to die from these injuries.
Approximately five percent of Americans have a serious mental illness, says Daumit, and these individuals are known to be two to three times more likely to die prematurely than people without severe psychiatric problems.
A small proportion of the greater risk, she says, can be credited to the higher risks of suicide and homicide victimization in this group, but those factors are not responsible for most of the difference. The two highest causes of death are cardiovascular disease and cancer, the same top causes for those who are not mentally ill.
Daumit, a practicing internist, believes this population could be “falling through the cracks.”
In the first study, the researchers analyzed data from 3,317 Maryland Medicaid recipients who had schizophrenia and bipolar disorder, and looked into whether the patients had developed cancer and, if so, what type of cancer they had.
They discovered that individuals with schizophrenia, when compared to the general population, were more than 4.5 times more likely to develop lung cancer, 3.5 times more likely to develop colorectal cancer and nearly three times more likely to develop breast cancer.
Those with bipolar disorder experienced similarly high risk for lung, colorectal and breast cancer. There were no racial differences in those who developed cancer in this group, whose average age was between 42 and 43 years.
Smoking could be the main reason for the elevated risk of lung cancer, says Daumit, which is more prevalent in people with serious mental disorders. She also speculates that the risk for breast cancer could be associated with the fact that women with schizophrenia and bipolar disorder are less likely to have children, and childbearing is believed to reduce breast cancer risk.
Furthermore, some psychotropic medications can raise levels of the hormone prolactin, a factor that has been associated with breast cancer. The colorectal cancer risk, she says, could be related to lifestyle issues, such as smoking, lack of physical activity and a diet lacking fruits and vegetables.
Daumit believes further research is needed on the role of behavioral and pharmacological factors in increased cancer risk among people with serious mental disorders, and whether this population receives appropriate cancer screening and treatment.
In the next study, Daumit’s team looked at similar Maryland Medicaid data from 1994 through 2001 in search of other patterns. They found that over the seven-year period, 43 percent of the 6,234 people with serious mental illness in the group were seen at a hospital emergency department.
Superficial injuries, open wounds and sprains were the most common types of injuries, with the least frequent being poisonings and burns. Daumit says the findings suggest that people with serious mental illness seem to be at greater risk for both intentional and unintentional injury, and the types of injuries were mostly associated with falls and minor violence.
People in this group are more likely to have substance abuse problems, and being under the influence of drugs or alcohol can increase injury risk, Daumit says.
Another factor that may be at play, she says, is low socioeconomic status, which is also associated with mental illness and injury risk stemming from unsafe housing and poorly maintained neighborhoods.
“Just as this population has other medical risks, injury requiring acute medical attention in the emergency department is common and we should consider this when we are looking at the overall care of the patient,” Daumit says.
The study is published in the journal Psychiatric Services.
Source: Johns Hopkins