Latent Structure of the Cigarette Purchase Task Among Treatment-Seeking Smokers With Depression and Its Predictive Validity on Smoking Abstinence.

Abstract

Research has recently shown that nicotine reinforcement is better characterized by a bifactorial latent structure: persistence (insensitivity to cigarette pricing) and amplitude (consumption at inexpensive prices). No study to date has examined its value as a predictor of abstinence. This study aimed to provide new evidence on the latent structure of the cigarette purchase task (CPT) in smokers with depressive symptoms and to examine whether the latent structure performs better as a predictor of continuous abstinence than do the individual indices. Participants (n = 205 smokers; 72% female: Beck Depression Inventory, Second Edition, M = 24.68, SD = 10.45) were randomized to two smoking cessation treatments for quitting smoking: cognitive behavioral treatment (CBT) or CBT + contingency management (CM). A principal-components analysis was conducted to examine the latent structure of the CPT and a set of regression models were performed to assess its predictive validity. The principal-components analysis revealed a bifactorial solution, which was interpreted as persistence (breakpoint, Omax, Pmax, and elasticity) and psychological inertia (intensity and elasticity of demand). Evidence on the convergent validity was obtained through significant associations between the two latent factors and smoking variables (all r values ≥.17). Psychological inertia was negatively related to the number of days of continuous abstinence at the end of treatment regardless of the treatment condition [R2 = .038; F(2, 202) = 4.989, p = .008]. Psychological inertia informs on which patients benefit less from smoking cessation treatments incorporating CM and CBT. Treatment components that affect individuals' excessive valuation of cigarettes might improve cessation outcomes. This is the first attempt to examine the latent structure of the CPT in depressed smokers and to yield evidence on its predictive validity. A specific bifactorial solution exists for this population: persistence (breakpoint, Omax, Pmax, and elasticity) and psychological inertia (intensity and elasticity). Isolating demand indices and factors provides a high-resolution characterization of nicotine reinforcement for depressed smokers in that it informs on treatment response. Compared to the individual CPT indices, psychological inertia more effectively predicts which patients benefit most from either CM or CBT. Treatment components that affect individuals' excessive valuation of cigarettes (eg, episodic future thinking) should be integrated into smoking cessation treatments.