Anhedonia, depressed mood, and smoking cessation outcome

Although the relation between lifetime depression and smoking cessation outcome has been well studied, the proposition that different symptomatic expressions of depression exert disparate predictive effects on risk of smoking cessation failure has largely gone uninvestigated. This study analyzed the individual contributions of depression's 2 hallmark affective symptoms, anhedonia (i.e., diminished interest in normally enjoyable activities) and depressed mood (i.e., elevated sadness), to the prediction of smoking cessation outcome.

Participants were adult daily smokers (N = 1,469; mean age = 45 years, 58% female, 84% White) enrolled in a smoking cessation treatment study. Lifetime history of anhedonia and depressed mood were classified via structured interview prior to quit day. Seven-day point prevalence smoking abstinence was assessed at 8 weeks and 6 months postquit.

When examined separately, both lifetime anhedonia, OR (95% CI) = 1.42 (1.16, 1.73), p = .004, and depressed mood, OR (95% CI) = 1.35 (1.11, 1.63), p = .002, predicted increased odds of relapse. These relations remained after adjusting for covariates, including lifetime depressive disorder, which did not predict outcome. After controlling for the covariation between lifetime anhedonia and depressed mood, anhedonia predicted cessation outcome, OR (95% CI) = 1.31 (1.05, 1.62), p = .02, while depressed mood did not (p = .19). Symptom duration (>2 weeks), treatment, and substance use disorder did not modify relations of lifetime anhedonia and depressed mood with cessation outcome.

Results suggest that (1) symptoms of affective disturbance capture depression-relevant risk of cessation failure, which is not adequately demarcated by the lifetime depressive disorder diagnosis, and (2) anhedonia is a more sensitive index of this affective disturbance than depressed mood per se. Clinical attention to anhedonia may facilitate smoking cessation.