Opioids Less Effective for Back Pain When Depressed

By Pat Anson, Editor

Patients who have low back pain are significantly less likely to get relief from opioid pain medication if they suffer from depression or anxiety, according to a new study published in the journal Anesthesiology.

Lower back pain is the leading cause of disability worldwide, with about 80 percent of adults experiencing back pain at some point in their lives. According to one recent study, about one in five low back pain patients also suffer from depression.

"High levels of depression and anxiety are common in patients with chronic lower back pain," said Ajay Wasan, MD, study author and professor of anesthesiology and psychiatry at the University of Pittsburgh School of Medicine.

"Learning that we are able to better predict treatment success or failure by identifying patients with these conditions is significant. This is particularly important for controlled substances such as opioids, where if not prescribed judiciously, patients are exposed to unnecessary risks and a real chance of harm, including addiction or serious side effects."

Wasan and his colleagues examined 55 chronic lower back pain patients with low- to-high levels of depression or anxiety. The patients were given morphine, oxycodone or a placebo to take orally for pain as needed over a six-month period.  

Patients with high levels of depression or anxiety experienced 50 percent less improvement in back pain (21% vs. 39% pain improvement) when compared to patients with low levels of depression or anxiety. They were also significantly more likely to abuse their medication.

Wasan says doctors should be cautious in prescribing opioids for depressed patients with back pain.

"It's important for physicians to identify psychiatric disorders prior to deciding whether to prescribe opioids for chronic back pain as well as treat these conditions as part of a multimodal treatment plan," he said

"Rather than refusing to prescribe opioids, we suggest that these conditions be treated early and preferably before lower back pain becomes chronic. For those prescribed opioids, successful treatment of underlying psychiatric disorders may improve pain relief and reduce the chance of opioid abuse in these patients."

A large study presented in March at the annual meeting of the American Academy of Orthopedic Surgeons found that depression, as well as obesity, smoking and alcohol use significantly raise the risk of having low back pain.

The study did not address the “chicken and egg question” of which came first. Does depression cause low back pain, or does low back pain lead to depression?

“With our study there was no way to determine the cause and the effect or which came first because there was so much overlap,” said lead author and orthopedic surgeon Scott Shemory, MD. “Especially with alcohol abuse and depressive disorders. Anybody who’s got low back pain for years and years, I don’t think it would be surprising that they would have a higher chance of depression or alcohol abuse.”

A leading U.S. medical organization recently urged its members not to prescribe opioids for back pain – whether patients are depressed or not. The American Academy of Neurology released a position paper last year saying the risk of serious side effects from opioids outweigh the benefits of pain relief. The Academy represents 28,000 neurologists and other healthcare providers.

“Whereas there is evidence for significant short-term pain relief, there is no substantial evidence for maintenance of pain relief or improved function over long periods of time without incurring serious risk of overdose, dependence, or addiction,” wrote Gary M. Franklin in the journal  Neurology.