Just over 60% of individuals who died from an opioid overdose had been diagnosed with a chronic pain condition, and many had been diagnosed with a psychiatric disorder, a study of more than 13,000 overdose deaths has found. The study, led by researchers at Columbia University Medical Center (CUMC), is the first to determine the proportion of those who died of an opioid overdose with chronic pain.

The findings were published online in the American Journal of Psychiatry.

According to the US Centers for Disease Control, the number of opioid-related deaths has quadrupled, from 8,048 in 1999 to 33,091 in 2015.

The researchers analyzed clinical diagnoses and filled medication prescriptions for more than 13,000 adults in the Medicaid program who died of an opioid overdose. During the last year of life, more than half of these individuals had been diagnosed with chronic pain. Many had also been diagnosed with depression and anxiety. “The frequent occurrence of treated chronic pain and mental health conditions among overdose decedents underscores the importance of offering substance use treatment services in clinics that treat patients with chronic pain and mental health problems. Such a strategy might increase early clinical intervention in patients who are at high risk for fatal opioid overdose,” said Mark Olfson, MD, professor of psychiatry at CUMC and lead investigator of the study.

Approximately one-third of those who died had been diagnosed with a drug use disorder in the prior year. However, fewer than one in twenty had been diagnosed with opioid use disorder in the last month. “Because clinical diagnoses generally indicate treatment, this service pattern suggests that dropout from drug treatment is common before fatal opioid overdose. Improving treatment retention with contingency management or other effective behavioral interventions might help lower the risk of fatal overdose in these patients,” said Dr. Olfson.

In the year before death, more than half had filled prescriptions for opioids or benzodiazepines, and many had filled prescriptions for both types of medications. “This medication combination is known to increase the risk of respiratory depression, which is the unusually slow and shallow breathing that is the primary cause of death in most fatal opioid overdoses,” said Dr. Olfson, who added that the data from the current study were collected between 2001 and 2007. “In the years since, there has been an increase in the proportion of US overdose deaths involving benzodiazepines and opioids.” The authors urged providers to restrict the combination, in the lowest possible dose and duration, to those patients for whom alternative strategies have proven inadequate.

The study is titled, “Service Use Preceding Opioid-Related Fatality.”