Associations Between Reductions in Depressive Symptoms and Reductions in Pain and Anxiety Symptoms and Substance Use: Emulation of a Randomized Trial.

Introduction: Depressive symptoms are linked with pain, anxiety, and substance use. Research estimating whether a reduction in depressive symptoms is linked to subsequent reductions in pain and anxiety symptoms and substance use is limited.

Methods: Using data from the Veterans Aging Cohort Study, a multisite observational study of U.S. veterans, the authors used a target trial emulation framework to compare individuals with elevated depressive symptoms (Patient Health Questionnaire-9 score ≥ 10) who experienced reductions in depressive symptoms (Patient Health Questionnaire-9 score < 10) with those whose symptoms persisted (Patient Health Questionnaire-9 score ≥ 10) at the next follow-up visit (on average, 1 year later). Using inverse probability of treatment weighting, the authors estimated ORs and 95% CIs for associations between depressive symptom reduction status and improvement on the following: anxiety symptoms, pain symptoms, unhealthy alcohol use, and use of tobacco, cannabis, cocaine, and/or illicit opioids.

Results: Reductions in depressive symptoms were associated with reductions in pain symptoms (OR=1.43, 95% CI=1.01, 2.02), anxiety symptoms (OR=2.50, 95% CI=1.63, 3.83), and illicit opioid use (OR=2.07, 95% CI=1.13, 3.81). Depressive symptom reductions were not associated with reductions in unhealthy alcohol use (OR=0.85, 95% CI=0.48, 1.52) or use of tobacco (OR=1.49, 95% CI=0.89, 2.48), cannabis (OR=1.07, 95% CI=0.63, 1.83), or cocaine (OR=1.28, 95% CI=0.73, 2.24).

Conclusions: Reducing depressive symptoms may potentially reduce pain and anxiety symptoms and illicit opioid use. Future work should determine whether reductions achieved through antidepressant medications, behavioral therapy, or other means have comparable impact.