Adam M. Leventhal

Chapter 9 explores the clinical relevance of implicit cognition in addiction, including the associations between drug dependence and implicit measures, relationships with clinical outcomes, and the effects of treatment on implicit measures. The chapter also presents a discussion on the clinical and measurement issues involved.

A growing literature suggests that anhedonia—an affective dimension related to the inability to experience pleasure—is associated with poor smoking cessation outcomes. Despite these findings, research of the motivational mechanisms linking anhedonia and smoking has been limited. Accordingly, the present study examined (a) relationships between anhedonia and motivationally relevant smoking characteristics and (b) whether anhedonia moderated the effects of tobacco deprivation on appetitive and aversive aspects of smoking urges. Smokers (N = 212; ≥5 cigarettes/day) first attended a baseline session during which measures of anhedonia and smoking characteristics were completed. Prior to a subsequent experimental session, a portion of participants were randomized to one of two groups: (a) 12-hr tobacco deprivation before the session (n = 51) and (b) ad libitum smoking (n = 69). Smokers with higher levels of anhedonia reported a greater number of past failed quit attempts and a higher proportion of quit attempts that ended in rapid relapse within 24 hr, rs > .20, ps < .05. Anhedonia did not consistently correlate with smoking heaviness, chronicity, and dependence motives. Anhedonia significantly moderated the influence of tobacco deprivation on appetitive smoking urges, such that deprivation effects on appetitive urges were stronger in high anhedonia smokers (β = .64) than in low anhedonia smokers (β = .23). Anhedonia did not moderate deprivation effects on aversive smoking urges. This pattern of results remained robust when controlling for baseline negative affect. These findings elucidate anhedonia’s link with smoking relapse and could be useful for developing cessation interventions for anhedonic smokers.

Cognitive processing biases toward smoking-related and affective cues may play a role in tobacco dependence. Because processing biases may occur outside conscious awareness, the current study examined processing of smoking-related and affective stimuli presented at subliminal conditions. A pictorial subliminal repetition priming task was administered to three groups: (1) Nonsmokers (n = 56); (2) Smokers (> or =10 cigarettes/day) who had been deprived from smoking for 12 h (n = 47); and (3) Nondeprived smokers (n = 66). Prime stimuli were presented briefly (17 ms) and were followed by a mask (to render them unavailable to conscious awareness) and then a target. Participants were required to make a speeded classification to the target. A posttask awareness check was administered to ensure that participants could not consciously perceive the briefly presented primes (i.e., smoking paraphernalia, neutral office supplies, and happy, angry, and neutral facial expressions). The groups differed in the degree to which they exhibited a processing bias for smoking-related stimuli, F(2, 166) = 4.99, p = .008. Deprived smokers exhibited a bias toward processing smoking (vs. neutral office supply) stimuli, F(1, 46) = 5.67, p = .02, whereas nondeprived smokers and nonsmokers did not (ps > .22). The three groups did not differ in the degree to which they exhibited a subliminal processing bias for affective stimuli. Tobacco deprivation appears to increase smokers' subliminal processing of smoking-related (vs. neutral) stimuli but does not influence subliminal processing of affective stimuli. Future research should investigate whether subliminal biases toward smoking-related stimuli influence relapse.

Major depressive disorder (MDD) is phenomenologically heterogeneous, which has prompted investigation of intermediate MDD phenotypes based on specific key symptoms. Presence and type of psychomotor disturbance may be an important psychopathologic feature that differentiates clinically distinct forms of juvenile MDD. This study examined the phenotypic status of three putative MDD phenotypes in a community sample of 941 youths: (1) agitated depression (MDD with psychomotor agitation), (2) retarded depression (MDD with psychomotor retardation), and (3) agitated–retarded depression (MDD with psychomotor agitation and retardation within an episode). Hasler et al.'s [2004: Neuropsychopharmacology 29:1765–1781] criteria of specificity (degree of association with relevant symptoms and conditions related to the disease of interest versus other psychiatric conditions), stability (degree of stability over time), and heritability (degree of familial aggregation with relevant conditions) were used to evaluate the phenotypic significance of these subtypes. Results were suggestive that agitated depression was a relatively specific phenotypic syndrome characterized by irritability, arousal, physical complaints, and vulnerability to anxiety disorders and alcohol dependence; low stability across depressive episodes; and low heritability. Agitated–retarded depression was relatively specific and characterized by increased severity, recurrence, vegetative symptoms, suicidal ideation, social impairment, endogeneity, and vulnerability to anxiety disorders and bulimia; low stability across episodes; and modest heritability. Although retarded depression was associated with some specific distinguishing characteristics, most associations were explained by the increased severity of this phenotype. Retarded depression evidenced little stability or heritability. These findings offer partial support of the phenotypic status of agitated and agitated–retarded depression in youths. Depression and Anxiety 0:1–18, 2007. Published 2007 Wiley-Liss, Inc.

This study evaluated whether psychiatric outpatients with a past stimulant use disorder in full remission for ≥ 2 months (STIM+, n = 204) and those with no history of stimulant use disorder (STIM−, n = 2070) differed in the prevalence of current anhedonia and amotivation. Results showed that a significantly greater proportion of STIM+ participants reported anhedonia and amotivation than STIM− participants. The relation between stimulant use disorder history and anhedonia remained robust after controlling for other relevant clinical and demographic factors. These findings suggest that anhedonia may be a preexisting risk factor or protracted effect of stimulant misuse.

Because different psychopathologic components of depressive symptoms may have distinct etiologies, examining their differential effects on smoking cessation may elucidate mechanisms underlying the smoking-depression relationship. Negative affect (NA), somatic features (SF), low positive affect/anhedonia (PA), and interpersonal disturbance (IP) have been identified as unique dimensions of depression that can be measured using the Center for Epidemiologic Studies Depression Scale (CESD). This study examined common and unique associations between CESD subscales and baseline smoking characteristics, nicotine withdrawal, and relapse in 157 participants enrolled in a smoking cessation trial for heavy social drinkers. Each dimension was univariately associated with negative and positive reinforcement smoking motives. Only SF had unique relations with tolerance smoking motives and univariate associations with nicotine dependence severity. Only PA predicted cessation-related changes in withdrawal symptoms on quit day. Analyses predicting abstinence at 8, 16, and 26 weeks post quit date showed that NA, SF, and PA each univariately predicted relapse, ps≤.0083. Only low PA predicted poorer outcomes incrementally to the other dimensions, even when controlling for level of nicotine dependence, smoking frequency, and history of major depression, p=.0018. Interventions targeting anhedonia and low positive affect may be useful for smokers trying to quit.