People who suffer from chronic back pain along with high levels of anxiety or depression are 75 percent more likely to abuse opioids than those with low levels of depression or anxiety, a new study suggests.

The study included 55 patients being treated for lower back pain with opioids, Medical News Today reports. They were given morphine, oxycodone or a placebo to take as needed for pain over a six-month period. They recorded their pain levels and how much medication they took daily.

Patients who suffered from high levels of depression or anxiety experienced 50 percent less improvement for back pain and 75 percent more opioid abuse, compared with patients who experienced low levels of depression or anxiety.

The study is published in Anesthesiology.

“High levels of depression and anxiety are common in patients with chronic lower back pain,” lead researcher Ajay Wasan, MD, of the University of Pittsburgh School of Medicine, said in a news release. “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.”

He said that instead of refusing to prescribe opioids, doctors who treat chronic pain should ensure patients who suffer from psychiatric disorders seek treatment for their mental condition. This may improve pain relief and reduce the chance of opioid abuse, he noted.