A new study, published in Annals of Behavioral Medicine, examines the interaction between depressive symptoms and smoking cessation. The results of the observational study, conducted in the Czech Republic, suggest that having depression may make it harder to quit smoking cigarettes, but that abstinence from smoking may be related to improvements in depressive symptoms.
“The present analysis provides further support for the hypothesis that smoking cessation may lead to improvements in depression,” state the authors, led by Lenka Stepankova, a lecturer for First Faculty of Medicine at Charles University and physician at General University Hospital in Prague.
Individuals with depression smoke cigarettes at double the rates of the general population. Some research has suggested that smoking cessation could worsen psychiatric symptoms. Yet, a recent meta-analysis (a method that combines data from multiple studies for statistical analysis) found that those who quit smoking experienced a decrease in depressive symptoms, with effects as strong as or stronger than antidepressants. And the authors note, “just as cessation may have effects on depression, depression also appears to affect cessation,” as a history of depression has been connected to less success in smoking cessation.
Unfortunately, research on treating co-occurring tobacco dependence and depression is sparse. In order to address this gap in the research, the researchers report, “The aims of the present analysis were to use data from clinical practice to assess (1) the association between baseline level of depression and 1-year smoking abstinence and (2) change in depression from baseline to 1-year follow-up in those who achieved abstinence.”
The researchers conducted an observational study, collecting data from 3,380 patient at the Center for Tobacco Dependence at General University Hospital in Prague. This center uses evidence-based treatments including counseling and pharmacotherapy to support patients to quit smoking. The researchers report that no specific treatment for depression was included. The center has a 1-year abstinence rate of 38%, which the authors report is “very high” compared to other smoking cessation programs.
Depression was reported in 29.7% of the sample. At 1-year, 37.1% of participants had quit smoking. Results show, “in comparison with patients without depression, patients with mild depression (OR = 0.71; 95% CI: 0.58 to 0.87, p = 0.01) were less likely to be abstinent and patients who reported moderate to severe depression were considerably less likely to be abstinent (OR = 0.51; 95% CI: 0.41 to 0.63, p < 0.001).” Pharmacotherapy was also associated with higher likelihood of abstinence. In addition, the number of visits was strongly correlated with abstinence. Patients who attended five or more visits were 5.91 times as likely to be abstinent at 1-year compared to patients who only attended one visit.
Researchers found, “The majority of patients with depression at baseline who remained abstinent from smoking reported improvements in their level of depression, while only a very small minority reported a higher level of depression at follow-up.”
The researchers identify important limitations to the study. Since the study was observational, causation cannot be determined. In addition, the researchers did not include data on depression at follow-up for individuals who were still smoking at 1-year. Therefore, it cannot be ruled out that patients who continued to smoke had similar reductions in depressive symptoms over time.
This study supports previous research and suggests that pre-existing depression may make it more challenging to quit smoking. Yet, abstinence from smoking may improve depressive symptoms for mild and moderate to severe depression. Given the high rates of depression in smokers, smoking cessation programs should be knowledgeable about patients’ struggles with depression and address depression in their treatment programs.
Stepankova, L., Kralikova, E., Zvolska, K., Pankova, A., Ovesna, P., Blaha, M., & Brose, L. S. (2016). Depression and smoking cessation: Evidence from a smoking cessation clinic with 1-year follow-up. Annals of Behavioral Medicine. Advance online publication. doi: 10.1007/s12160-016-9869-6 (Abstract)