Seriously mentally ill individuals have a much higher death rate than the general population.
On the surface, this may just seem like a probable consequence of having a serious mental illness. For example, much attention is paid to the increased suicide risk among those with major depression, schizophrenia or bipolar disorder.
Although this does contribute to the higher likelihood of death among the mentally ill, it is not the primary cause. In fact, those with psychiatric conditions are more likely to die from a lot of different causes than the general population – most notably from chronic physical illness such as heart and lung disease or cancer. There are 10 times as many deaths from these causes as there are from suicide among the mentally ill.
It has long been known that physical and psychiatric illness often go together. When one is present, it seems to worsen the other – in both directions. For example, depression is known to worsen outcomes in physical illness such as heart disease and at the same time, when physical illness begins, it tends to have an immediate effect to worsen symptoms of depression.
According to researchers in the field, the death rate for people with mental illness is about 70 percent higher than in the general population – and worse for those with schizophrenia. People with major mental illness often die up to 25 years earlier than their non-mentally ill peers.
In a review paper examining the scale of this problem, researchers learned that the highest death risk is among patients with severe mental illness and that 72 percent of the excess deaths occur in patients who have only ever attended general practice for their psychiatric care.
The problem of excess mortality is present in all clinical settings and has been around for centuries. All of this begs the question – why do we have so many unnecessary deaths among the mentally ill?
A few theories exist about the reasons for this problem. For one thing, many of the risk factors for chronic illness are preventable and involve lifestyle modification. Things like smoking, obesity, high blood pressure and cholesterol.
We know that some of these issues are particularly common among the mentally ill. For example, up to 80 percent of people with schizophrenia also smoke and some of the medications commonly used to treat this condition can cause significant weight gain. People with mental illness are more likely to smoke, drink and use drugs and less likely to exercise at recommended levels than the general population.
Perhaps individuals dealing with severe mental illness are missing out on opportunities to prevent or treat these issues when the rest of the population is not.
But lifestyle factors are not the only explanation. When it comes to cancer, the incidence of many forms is no higher than in the general population, but those with co-existing mental illness are more likely to die from their cancer.
Some other explanations for an increased death rate could include a lower compliance with treatment for chronic illness, issues with communication or an overlap between psychiatric and physical symptoms which could make it harder to diagnose chronic illness.
All of this simply points to the importance of educating health care providers in all settings about increased risks and ensuring regular health screening for patients dealing with mental illness. We could do a lot toward preventing as many as 33,000 unnecessary deaths each year in Canada.