Over Half of All Opioid Prescriptions Go to Mentally Ill Patients, Study Finds

A new study indicates that adults with mental health disorders receive more than 51% of all opioids prescribed in the United States each year, further illustrating the complex relationship between mental health and substance abuse.

As the opioid epidemic continues to claim lives, a particular concern is its toll on the already vulnerable population of the mentally ill. Prior research indicated that people with mental health disorders have higher rates of chronic pain, opioid prescriptions, and long-term opioid use, but other studies have proposed that mental illness may mitigate the association between pain and opioid use. In an attempt to clarify the issue, researchers set out to investigate this relationship and “derive national estimates of opioid use among Americans with mental health disorders and to examine factors associated with such use.”

Their study, which is to be published in the July issue of the Journal of the American Board of Family Medicine, used data from the Medical Expenditure Panel Survey to identify a sample of more than 51,000 adults who participated in the survey in 2011 and 2013. After linking survey answers to clinical data on healthcare utilization, the researchers determined which participants had a mental health disorder, such as anxiety, depressive, or episodic mood disorders. They also classified opioid users as those who filled at least 2 opioid prescriptions in a calendar year, based on pharmacy data.

Based on the rate of mental illness in the sample, the researchers projected that 38.6 million of the 239.4 million US adults have a mental health disorder. Nearly 1 in 5 (18.7%) of those with mental health disorders used opioids, while just 5% without mental health disorders were opioid users. Of the 115 million opioid prescriptions written each year, more than half (51.4%) go to adults with a mental health disorder.

In unadjusted analyses, opioid use was more than 4 times more likely among adults with mental health disorders than among those without. This association was still significant after adjusting for sociodemographic characteristics and health status and utilization, as the mentally ill were over twice as likely to use opioids.

Looking further into individual characteristics, the researchers found that mentally ill patients who used opioids were less physically healthy, more likely to have comorbidities, and had higher reported levels of pain than non-users with mental illness. Even among clinical subgroups, such as cancer diagnosis and self-reported pain levels, mental illness was associated with higher likelihood of opioid use. For instance, among all adults with chronic pain, the mentally ill were almost twice as likely to be opioid users than those without mental health disorders (45.3% vs 24.1%).

The researchers hypothesized that mentally ill patients present a set of complex clinical factors that increase the likelihood of a clinician prescribing opioids, despite the fact that clinicians are advised to suggest nonopioid alternatives for this population due to the elevated risk of overdose. However, pain is subjective and likely intertwined with mental health symptoms, further complicating the relationship between mental illness and opioid use.

Further research could help clarify this relationship and identify safer pain management strategies for the mentally ill, the researchers wrote. In the meantime, their findings indicate that “improving treatment of comorbid mental health disorders and pain will be an important focus when trying to reduce the overall negative impacts of opioid use on patients and communities.”