Using opioids for more than a month caused a spike in depression.

Long-term use of opioids may trigger depression, a new study finds.

Use of opioids for more than 30 days is believed to lead to changes in neuroanatomy, according to research published in Annals of Family Medicine in January.

Researchers at Saint Louis University analyzed data from close to 108,000 patients, including those at the Veterans Health Administration, who had no history of depression. 

Practitioners “should be aware that opioid analgesic use of longer than 30 days imposes risk of new-onset depression,” wrote author Jeffrey Scherrer, Ph.D., of SLU.

Opioid drugs in the study included codeine and morphine.