Depression and Opioid Use: Recognizing the Need for Dual Diagnosis Treatment

Opioids are designed to treat both acute and chronic physical pain and, indeed, that is the purpose of most opioid prescriptions. But there is mounting evidence that the majority opioid prescriptions are given to people who are struggling with a different kind of pain: depression and other mood disorders. “More than half of all opioid prescriptions in the United States are written for people with anxiety, depression, and other mood disorders,” says Catharine Caruso of Stat News. At the same time, people who suffer from depression are 2-3 times more likely to misuse prescription opioid medications than the general population, even if they have no prior history of drug abuse.

Many researchers now believe that depression is one of the primary causes of opioid abuse. While 5% of the general population uses prescription opioids of some kind, that number jumps to 19% amongst people with mood disorders. In raw numbers, that means over 30 million opioid prescriptions each year are being written for people with mood disorders. Dr. Brian Sites, author of a newly released study examining opioid prescribing patterns from 2011-2013, says:

If you want to come up with a social policy to address the need to decrease our out-of-control opioid prescribing, this would be the population you want to study because they’re getting the bulk of the opioids and then they are known to be at higher risk for the bad stuff.

For many, this combination of increased likelihood of receiving an opioid prescription and higher propensity for abusing that medication can have devastating consequences.

So why are people with depression more likely to receive or seek out opioid prescriptions? The answers are not entirely clear. What we do know, however, is that depression is linked to chronic pain; people with pre-existing depression are more prone to developing chronic pain while people with pre-existing chronic pain are more likely to become depressed. Additionally, people with depression may experience pain differently—and more intensely—than people without depression.

As a study published last year in The Journal of Pain found, people with depression had lower pain thresholds and higher pain sensitivity than non-depressed subjects. This was particularly true for people whose depression had anxious features. While lifestyle factors such as poor sleep and low levels of physical activity may account for a portion of this difference, pain sensitivity, in particular, remained significantly higher in depressed subjects, even when lifestyle factors were accounted for.

Some researchers believe that the cause of this exacerbated acute and chronic pain perception arises from the neurological behavior of depression itself. “People with depression show abnormalities in the body’s release of its own, endogenous, opioid chemicals,” Olga Khazan writes in The Atlantic. In other words, your brain is not capable of alleviating pain in the same way that of a non-depressed person can via natural opioid release. Additionally, Mark Sullivan, a professor of psychiatry at the University of Washington, says, “Depressed people are in a state of alarm. They’re fearful, or frozen in place. There’s a heightened sense of threat.” Some theorize that it is precisely that heightened state of fearfulness that augments perceptions of pain.

But the connection between depression and opioid use isn’t necessarily about physical pain at all. Research reveals that people with depression are significantly more likely to continue taking opioid medications even after their physical pain has resolved, indicating that bodily pain is not the primary motivator for opioid abuse. “If the emotional pain, the depression, is never properly diagnosed or treated, the patient might continue taking the opioid because it’s treating something,” says Jenna Goesling, assistant professor in the department of anesthesiology at the University of Michigan.

Indeed, research suggests that opioids have antidepressant properties in their own right. “There is a generally accepted hypothesis that long distance running produces a ‘runner’s high’ via the production of endorphins, one of the brain’s opioids,” writes Anna Fels for The New York Times. People who employ running as part of their depression management strategy “often experience feelings of malaise and low mood—not unlike patients who miss a day or two of their antidepressants.”

Prescription opioids can mimic this natural high by working on the brain’s opioid receptors, causing feelings of euphoria and the minimization of depressive symptoms. In fact, opioid medication buprenorphine is now being investigated for the treatment of depression that has not responded to typical antidepressant medication with promising results. For many, this comes as no surprise; “opioids have a long history of being used to treat melancholia and other psychological disorders—right up until the 1950s, when the current group of antidepressants were discovered.”