Trait-impulsivity moderates the relationship between rumination and number of major depressive episodes among cigarette smokers

Background. Despite the high prevalence of major depression among cigarette smokers, little is known about biobehavioral mechanisms that increase smokers' susceptibility to depression. Aims. The present study examined whether trait-impulsivity would moderate the relationship between rumination and number of past major depressive episodes (MDEs) among smokers (N=128). Method. Data were derived from baseline screening questionnaires and structured diagnostic interviews of two studies examining emotional responses of smokers with a history of major depression compared with smokers without depression histories. Results. As predicted, the interaction between rumination and trait-impulsivity was a significant predictor of MDE recurrence (β=0.259, p=0.001, R ² change=0.063). Post hoc analyses tested rumination's association with past MDEs among those with high and low levels of impulsivity. Rumination predicted the number of diagnosed past MDEs among those with high levels of impulsivity (β=0.408, p=0.006, R² change=0.104), but not among those with low levels of impulsivity (β=0.203, p=0.126, R² change=0.028). Conclusions. High levels of trait-impulsivity may increase vulnerability to rumination and MDE recurrence among smokers, potentially, facilitating the likelihood of experiencing clinically relevant depressogenic consequences (e.g. suicidal ideation and behavior).