Conditions in which chronic pain is a symptom, including spinal pain, cancer, and arthritis, were most commonly found in people who died by suicide. Nearly 9 percent of suicide deaths showed evidence of chronic pain. These are results of a large, retrospective analysis published online in Annals of Internal Medicine on September 11.
Since 1999, suicide rates have steadily increased, and suicide is now the 10th leading cause of death in the United States. The prevalence of chronic or severe pain has also risen, and researchers believe it could be contributing to the rise in suicide rates.
To determine the connection between chronic pain and suicide, a team of researchers at the US Centers for Disease Control and Prevention (CDC) in Atlanta collected data from 18 states participating in the National Violent Death Reporting System (NVDRS). The NVDRS is an active, state-based surveillance system that links data on violent deaths, such as suicides, from death certificates, coroner or medical examiner reports, and law enforcement reports into a single incident record. The NVDRS defines suicide as death that results from the intentional use of force against oneself.
The data included people aged 10 years or older who died by suicide between January 1, 2003 and December 31, 2014. Using keyword searches for 120 medical conditions and nine pain types—based on definitions from the American Chronic Pain Association—the team identified cases with evidence of chronic pain in the coroner or medical examiner and law enforcement narratives.
Researchers assessed the percentage of people who died by suicide who also experienced chronic pain as well as those who died from an overdose of opioids—prescription or illicit. They also analyzed demographic data, how the person died (gunshot, opioid overdose, other poisoning, and hanging or suffocation, for example), toxicology results, and precipitating circumstances such as poor mental health, substance abuse, interpersonal problems, and life stressors.
During the study period, the CDC identified 123,181 individuals who died by suicide, including 10,789 who experienced chronic pain. From 2003 to 2014, the percentage of suicides with chronic pain rose from 7.4 percent to 10.2 percent. However, the percentage of those who died by opioid overdose remained low overall—less than 2 percent.
The most common source of pain was spine pain—including back pain, degenerative disc disease, and spinal stenosis—and made up nearly a quarter of suicides with chronic pain. The second most common type was musculoskeletal pain, which included arthritis, fibromyalgia, and lower limb pain, and accounted for 20.8 percent. Disease-related pain from cancer, chronic obstructive pulmonary disease, and lupus, made up about 16 percent of suicides.
Among people who died by suicide, 51.7 percent who had chronic pain and 44.1 percent who had no pain had a known mental health condition; depression was the most common diagnosis in both groups with 81.9 percent versus 74.6 percent.
In addition, 53.6 percent of suicides with chronic pain died by gunshot versus 51.4 percent without chronic pain. Meanwhile, overdose on opioids—both prescription and illicitt—was higher among those with chronic pain (16.2 percent) than those without (3.9 percent).
"We cannot draw definitive conclusions regarding the proportion of suicides directly attributable to chronic pain, [but] our narrative review of suicide notes suggests that the proportion was not trivial," wrote the researchers, led by Emiko Petrosky, MD, MPH, of the CDC.
The team emphasized that anyone caring for patients with chronic pain should be aware of the potential increased risk for suicide. The researchers also argued for more efforts to be made to diagnose, manage, and treat chronic pain and co-existing mental health conditions.
Overall, the researchers said, their findings warrant further investigation to better understand the complexities of chronic pain.