A temporal relationship between nonmedical opioid Use and major depression in the U.S.: A Prospective study from the National Epidemiological Survey on Alcohol and Related Conditions.

•Both symptoms of major depression and major depression diagnosis predict the new onset of Non-medical opioid use in the US population•Past-year non-medical use of opioids predicts the new onset of symptoms of major depression, but not the major depression diagnosis in the US population•Early identification and intervention on the progress of major depression among opioid users may reduce non-medical opioid use. In addition, opioid misuse monitoring programs targeting people suffering from depression help alleviate their mental conditions.