Mentally ill people have a far greater risk of committing suicide up to 36 years after they were hospitalised for their illness, a new Danish study shows.
The study – the first of its kind – investigated the long-term risks for suicides among the mentally ill; it analysed suicides among 176,347 Danes born between 1955 and 1991.
According to the study, men who suffer from schizophrenia, bipolar disorder and depression run a six percent risk of suicide, while the figure for women with the same disorders is four percent. The equivalent figures for the general public are 0.7 and 0.3 percent, respectively.
“All mental illnesses increase a person’s risk of committing suicide,” says Professor Merete Nordentoft of the Department of Neurology, Psychiatry and Sensory Sciences at the University of Copenhagen, who headed the study.
“But until now it has been uncertain how much higher the long-term risks were for psychiatric patients compared with the rest of the population, and which psychiatric disorders increased the risk the most,” she adds.
Denmark has the oldest continuous records of mentally ill patients in the world. This provided Professor Merete Nordentoft with a unique opportunity to study the long-term risk of suicide among psychiatric patients.
In her study, Nordentoft made use of the Danish Psychiatric Central Research Register and the Cause of Death Registry.
She studied the patients’ records for up to 36 years from the patient’s first hospitalisation or outpatient visit for psychiatric treatment.
The team also set out to find which psychiatric patients had the highest risk of suicide. They found that mentally ill patients who have already attempted suicide have a risk of dying from suicide later in life that is twice as high as those who have not attempted suicide.
Alcohol and drug abuse are also factors that increase the risk of suicide considerably. Anorexia is another one – anorectic women have a 2.5 percent risk of suicide; the study is inconclusive for anorectic men, since the number of men with anorexia is very low.
“Our study has some pointers that are quite interesting in terms of working with people with a psychiatric disorder,” says Nordentoft. “The situation is not as bad as we feared: some textbooks say that 10 to 15 percent of mentally ill people commit suicide, but luckily the real figure is much lower.”
Suicide among mentally ill people is nevertheless a great problem as the number of suicides is 10 to 20 times higher than in the rest of the population.