Co-traveling of smoking in people with remitted, recurrent and repeated depression

Smoking remains a serious problem in depressed persons. Those with a more persistent MDD course may have the most unfavorable smoking outcomes.

To (i) compare smoking outcomes (smoking risk, smoking trajectories) over six years across persons with remitted, recurrent and repeated MDD, and (ii) investigate the role of additional putative risk indicators for smoking outcomes.

We included 703 participants from the Netherlands Study of Depression and Anxiety (NESDA) with current MDD at baseline. MDD course and smoking outcomes were reassessed at 2, 4, and 6 years. Across persons with remitted (54.2%), recurrent (34.0%) and repeated (11.8%) MDD, smoking outcomes were compared with generalized estimating equations (smoking risk over time) and logistic regression (smoking trajectories among baseline smokers; n = 268). Putative risk factors of poorer smoking outcomes were explored.

Over 6 years, smoking risk did not decline among persons with repeated MDD (OR 1.04, 95%CI 0.94-1.14; p = 0.48), as opposed to (interaction p < 0.01) a decrease in recurrent (OR 0.87, 95%CI 0.81-0.94; p < 0.001) and remitted MDD (OR 0.87, 95%CI 0.82-0.93; p < 0.001). Also, baseline smokers with repeated compared to more remitting MDD were at increased risk of repeated versus non-repeated smoking (OR 3.72, 95%CI 1.20-11.56, p = 0.023). Only lower neuroticism, higher income, and higher education level also adversely impacted on smoking risk.

Causality cannot be inferred.

A disparity of smoking risk over time in disadvantage of persons with a more persistent versus a more remitting MDD course occurs. The absence of durable clinical MDD remission may be a likely explanation.