Background: Knowledge of mental disorders among patients with persistent opioid use for the treatment of chronic non-cancer pain is essential, as mental disorders and symptoms can exacerbate or perpetuate pain and impact on the ability of patients to manage their illness. We have studied the prevalence of mental disorders and symptoms, including substance use disorders, in patients with persistent opioid use in 2019.
Material and method: Persons ≥ 18 years with persistent opioid use and persons ≥ 18 years with at least one registered mental disorder in the specialist healthcare service in 2019 were included. Data were retrieved from national health registries in Norway. Patients who received opioids reimbursed for the treatment of chronic pain were compared with those who received opioids without reimbursement.
Results: The prevalence of mental disorders and symptoms was 34 % among 14 403 persons who received reimbursed opioids, and 42 % among 38 001 persons who received opioids without reimbursement. This is equivalent to a two to threefold increase in prevalence compared to the general population. There was a particularly higher prevalence of anxiety disorders and substance use disorders. The prevalence of mental disorders and symptoms was highest in the age group 18-44 years (49-55 %).
Interpretation: Among patients with persistent opioid use, a large proportion had mental disorders and symptoms, which are known risk factors for developing problematic opioid use and opioid use disorder.