Treatment-resistant depression could increase risk of substance use disorder

As part of a Swedish study, a team of researchers found that patients with treatment-resistant depression could be at a higher risk of developing a substance use disorder compared to other patients with a less chronic form of refractory depression.

Researchers at Karolinska Institutet made the determination by examining data from national health registries of over 121,000 patients with clinical depression between 2006 and 2014. Patients diagnosed with treatment-resistant depression underwent at least three antidepressive drug treatments. The team then compared these patients to their counterparts to determine the risk of developing a substance use disorder or referral for drug treatment to treat the condition.

“We observed a generally higher risk of substance use syndrome both in people who have no history of substance use syndrome and in those who have had such problems,” researchers stated in a news release.

According to the findings, after one year of antidepressive treatment, patients without a history of a substance use disorder were 51 percent more likely to receive a diagnosis of treatment-resistant depression. “The risk was highest for opiates and sedatives – almost two and three times as high respectively. In patients with a history of substance abuse, the increase in risk was 23 percent, with an elevated risk in the sub-categories of sedatives and multiple substance use,” the findings showed.

“Our results shed light on the consequences that people with insufficiently treated depression may be at higher risk for, and the importance of quickly identifying those who do not respond to antidepressants in order to provide the most intense therapy needed to avoid these consequences.”

The study was published in the journal Addiction and initiated in collaboration with pharmaceutical company Janssen Pharmaceuticals.