In a study published online in the Journal of Psychosomatic Research, researchers evaluated three theoretical models regarding the association between cigarette smoking and depressive symptoms in patients with type 2 diabetes (T2D): cigarettes per day (CPD) predicts depressive symptoms, depressive symptoms predict CPD, and the relationship between CPD and depressive symptoms is bidirectional. Data from the Evaluation of Diabetes Treatment Study were used; 296 patients reported being current smokers at baseline. The researchers collected CPD and depressive symptom data for four years and estimated path models corresponding to the three theoretical models. The best-fitting model was determined using Akaike’s Information Criterion (AIC). Based on AIC value, the best-fitting model was determined to be that CPD predicts depressive symptoms.