1. The Research Question
Does longer duration of prescription opioid use lead to new onset depression when controlling for maximum daily dose, pain and other confounders?
Does maximum daily dose of prescription opioid use lead to new onset depression when controlling for duration of use, pain and other confounders?
BP34 Adherence to Antibiotic Prescribing for LRTI and Association With Recovery (Oral Presentation On Completed Research) Nick Francis, MD, PhD, Cardiff University; David Gillespie; Jacqueline Nuttall; Paul Little; Theo Verheij; Samuel Coenen; Jochen Cals; Kerenza Hood; Herman Goossens; Christopher Butler

2. What the Researchers Did
Retrospective cohort design using patient data from:
Veterans Administration (VA), n= 70,997
Baylor Scott & White (BSW), n=13,777
Henry Ford Health System (HFHS), n=22,981
Variables created from ICD-9-CM codes, pharmacy records, vital signs, lab results etc.
Confounding controlled by Inverse Probability of Treatment Weighting using Propensity Scores
Separate Cox models computed to estimate association between opioid duration, morphine equivalent dose and new diagnosis of depression
aged ≥18 years, consulting with an illness where an acute or worsened cough was the main or dominant symptom, or had a clinical presentation that suggested a lower respiratory tract infection that had been present for ≥28 days.

3. What the Researchers Found
Risk of new onset depression increased with opioid duration in each patient sample. As shown in Table 1, >90 day use was associated with 35% to 105% increased risk of new onset depression compared to 1-30 use.
Dose was not associated with new onset depression

4. What This Means for Clinical Practice
1. Baseline depression screening insufficient, consider depression screening at each opioid refill 2. Add depression to risk – benefit discussion 3. Short term euphoria but long term depression 4. Opioid taper if new onset depression in chronic pain 5. Consider opioid, not just pain, as source of depression