Depressive symptoms and smoking: Effect on mortality in a primary care cohort

• Published in: Journal of psychosomatic research Vol. 182; p. 111690
• Main Authors: Rantanen, Ansa Talvikki, Kautiainen, Hannu, Ekblad, Mikael Oskari, Korhonen, Päivi Elina
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.07.2024
• Subjects: Adult; Aged; Cardiovascular Diseases - mortality; Cause of Death; Cohort Studies; Depression - mortality; Depression - psychology; Depressive symptoms; Female; Finland - epidemiology; Humans; Male; Middle Aged; Mortality; Primary care; Primary Health Care - statistics & numerical data; Prospective Studies; Psychiatric/Mental Health; Risk Factors; Smoking; Smoking - epidemiology; Finland; Depressive symptoms; Primary care; Mortality; Smoking
• ISSN: 0022-3999; 1879-1360; 1879-1360
• DOI: 10.1016/j.jpsychores.2024.111690

Depressive symptoms have been suggested to increase mortality risk but causality remains unproven. Depressive symptoms increase likelihood of smoking which is thus a potential factor modifying the effect of depressive symptoms on mortality. This study aims to assess if the association of depressive symptoms and all-cause mortality is affected by smoking. A prospective cohort study in Finnish primary care setting was conducted among 2557 middle-aged cardiovascular disease (CVD) risk persons identified in a population survey. Baseline depressive symptoms were assessed by Beck's Depression Inventory (BDI) and current smoking by self-report. Data on mortality was obtained from the official statistics. Effect of depressive symptoms and smoking on all-cause mortality after 14-year follow-up was estimated. Compared to non-depressive non-smokers, the adjusted hazard ratio (HR) for all-cause mortality was 3.10 (95% CI 2.02 to 4.73) and 1.60 (95% CI 1.15 to 2.22) among smoking subjects with and without depressive symptoms, respectively. Compared to the general population, relative survival was higher among non-depressive non-smokers and lower among depressive smokers. Relative standardized mortality ratio (SMR) for all-cause mortality was 1.78 (95% CI 1.31 to 2.44) and 3.79 (95% CI 2.54 to 6.66) among non-depressive and depressive smokers, respectively, compared to non-depressive non-smokers. The HR for all-cause mortality and relative SMR of depressive non-smokers were not increased compared to non-depressive non-smokers. Current smoking and increased depressive symptoms seem to additively contribute to excess mortality. •The combination of depressive symptoms and smoking is especially harmful.•Depressive symptoms and smoking additively contribute to excess mortality.•Depressive smokers have tripled mortality risk compared to non-smokers.•They have doubled relative standardized mortality compared to non-depressive smokers.•Mortality of depressive non-smokers is similar to non-depressive non-smokers.