The dopamine D2 receptor mediates approach-avoidance tendencies in smokers

Dopamine D2 receptors (DRD2) have been strongly implicated in reward processing of natural stimuli and drugs. By using the Approach-Avoidance Task (AAT), we recently demonstrated that smokers show an increased approach bias toward smoking-related cues but not toward naturally-rewarding stimuli. Here we examined the contribution of the DRD2 Taq1B polymorphism to smokers’ and non-smokers’ responsivity toward smoking versus naturally-rewarding stimuli in the AAT. Smokers carrying the minor B1 allele of the DRD2 Taq1B polymorphism showed reduced approach behavior for food-related pictures compared to non-smokers with the same allele. In the group of smokers, a higher approach-bias toward smoking-related compared to food-related pictures was found in carriers of the B1 allele. This pattern was not evident in smokers homozygous for the B2 allele. Additionally, smokers with the B1 allele reported fewer attempts to quit smoking relative to smokers homozygous for the B2 allele. This is the first study demonstrating that behavioral shifts in response to smoking relative to natural rewards in smokers are mediated by the DRD2 Taq1B polymorphism. Our results indicate a reduced natural-reward brain reactivity in smokers with a genetically determined decrease in dopaminergic activity (i.e., reduction of DRD2 availability). It remains to be determined whether this pattern might be related to a different outcome after psychological cessation interventions, i.e. AAT modification paradigms, in smokers

The effects of psychological stress on approach tendencies for smoking-related cues in smokers

Stress may potentiate the chronification of nicotine addiction, but the exact mechanisms remain elusive. We performed an explorative pilot study examining the effects of psychological stress, administered via the socially evaluated cold pressor task (SECPT), on implicit approach bias for smoking-related cues in smokers in the approach-avoidance task (AAT). Smokers (N=24) were subjected to the stress or control condition of the SECPT by using a within-subject design. Consistent with previous findings, a strong approach bias for smoking-related cues in the AAT was found in smokers. Exposure to stress did not affect the general bias for smoking-related cues in the AAT relative to the control condition of the SECPT. In additional explorative analyses, an interaction between carbon monoxide (CO) levels in expired air, cortisol levels, and stress on approach bias for smoking-related cues was found. Higher CO levels, possibly due to recent smoking, prior to stress exposure were associated with an approach bias for smoking-related cues. Our findings suggest that CO levels in interaction with stress can modulate implicit, automatic processing in the context of nicotine-addiction. Our findings might provide novel cues to how stress influences cigarette craving and smoking behavior

Approach bias modification in inpatient psychiatric smokers

Item does not contain fulltextDrug-related automatic approach tendencies contribute to the development and maintenance of addictive behavior. The present study investigated whether a nicotine-related approach bias can be modified in smokers undergoing inpatient psychiatric treatment by using a novel training variant of the nicotine Approach-Avoidance-Task (AAT). Additionally, we assessed whether the AAT-training would affect smoking behavior. Inpatient smokers were randomly assigned to either an AAT-training or a sham training condition. In the AAT-training condition, smokers were indirectly instructed to make avoidance movements in response to nicotine-related pictures and to make approach movements in response to tooth-cleaning pictures. In the sham-training condition, no contingency between picture content and arm movements existed. Trainings were administered in four sessions, accompanied by a brief smoking cessation intervention. Smoking-related self-report measures and automatic approach biases toward smoking cues were measured before and after training. Three months after training, daily nicotine consumption was obtained. A total of 205 participants were recruited, and data from 139 participants were considered in the final analysis. Prior to the trainings, smokers in both conditions exhibited a stronger approach bias for nicotine-related pictures than for tooth-cleaning pictures. After both trainings, this difference was no longer evident. Although reduced smoking behavior at posttest was observed after both trainings, only the AAT-training led to a larger reduction of nicotine consumption at a three-month follow-up. Our preliminary data partially support the conclusion that the AAT might be a feasible tool to reduce smoking in the long-term in psychiatric patients, albeit its effect on other smoking-related measures remains to be explored.8 p

"Push it!" or "Hold it!"? A comparison of nicotine-avoidance training and nicotine-inhibition training in smokers motivated to quit

Rationale: Recently, experimental paradigms have been developed to strengthen automatic avoidance or inhibitory responses for smoking cues. However, these procedures have not yet been directly compared regarding their effectiveness and mechanisms of action. Objective: This study compared the effects of avoidance vs. inhibitory training as an add-on to a brief smoking cessation intervention. The standard Approach-Avoidance-Task (AAT) was adapted for both training types and control conditions. Methods: One hundred twenty-four smokers attended behavioral counseling for smoking cessation and were thereafter randomized to one of four training conditions: avoidance-AAT, sham-avoidance-AAT, inhibition-AAT, sham-inhibition-AAT. During a 2-week training period including five training sessions, smokers in the avoidance-AAT trained to implicitly avoid all smoking-related cues, while smokers in the inhibition-AAT trained to implicitly inhibit behavioral response to smoking cues. During sham training, no such contingencies appeared. Self-report and behavioral data were assessed before and after training. Cigarette smoking and nicotine dependence were also assessed at 4- and 12-week follow-ups. Results: At posttest, avoidance training was more effective in reducing daily smoking than inhibition training. However, this difference was no longer evident in follow-up assessments. All training conditions improved other smoking- and health-related outcomes. Neither training changed smoking-related approach biases or associations, but approach biases for smoking-unrelated pictures increased and Stroop interference decreased in all conditions. Smoking devaluation was also comparable in all groups. Conclusions: Avoidance training might be slightly more effective in reducing smoking than inhibitory training. Overall, however, all four training types yielded equivalent therapy and training effects. Hence, a clear preference for one type of training remains premature