Impulsivity and symptoms of nicotine dependence in a young adult population

Individual differences in delay discounting are associated with dorsal prefrontal cortex connectivity in children, adolescents, and adults

Delay discounting is a measure of impulsive choice relevant in adolescence as it predicts many real-life outcomes, including obesity and academic achievement. However, resting-state functional networks underlying individual differences in delay discounting during youth remain incompletely described. Here we investigate the association between multivariate patterns of functional connectivity and individual differences in impulsive choice in a large sample of children, adolescents, and adults. A total of 293 participants (9-23 years) completed a delay discounting task and underwent 3T resting-state fMRI. A connectome-wide analysis using multivariate distance-based matrix regression was used to examine whole-brain relationships between delay discounting and functional connectivity. These analyses revealed that individual differences in delay discounting were associated with patterns of connectivity emanating from the left dorsal prefrontal cortex, a default mode network hub. Greater delay discounting was associated with greater functional connectivity between the dorsal prefrontal cortex and other default mode network regions, but reduced connectivity with regions in the dorsal and ventral attention networks. These results suggest delay discounting in children, adolescents, and adults is associated with individual differences in relationships both within the default mode network and between the default mode and networks involved in attentional and cognitive control.

Grazing Is Associated with ADHD Symptoms, Substance Use, and Impulsivity in a Representative Sample of a Large Metropolitan Area in Brazil

Grazing is a clinically relevant eating behaviour, especially when it presents with a sense of loss of control (compulsive grazing). There is evidence that other disordered eating patterns are associated with problematic substance use and impulsivity-related conditions, such as attention-deficit/hyperactivity disorder (ADHD). This overlap contributes to higher psychopathology and treatment complications. Less is known about grazing, and most information originates in high-income countries. Hence, we sought to investigate relationships between grazing, tobacco and alcohol use, ADHD, and impulsivity in a large representative sample from Brazil. Data were collected by trained interviewers from adults (N = 2297) through an in-person household survey based on a stratified and clustered probability sample. We found significant associations between compulsive grazing and problematic alcohol use (OR = 3.02, 95% CI: 1.65, 5.53), ADHD (OR = 8.94, 95% CI: 5.11, 15.63), and smoking (OR = 1.67, 95% CI: 1.12, 2.47), with impulsivity contributing to the first two relationships. The substantial association with ADHD suggests that other executive functions may promote disordered eating, possibly expressed through difficulties in adhering to regular meals. Clinically, these findings highlight the importance of assessing problematic eating patterns, such as compulsive grazing, in those presenting with difficulties with substance use or impulsivity, and vice versa.

Individual Differences in Delay Discounting are Associated with Dorsal Prefrontal Cortex Connectivity in Youth

Delay discounting is a measure of impulsive choice relevant in adolescence as it predicts many real-life outcomes, including substance use disorders, obesity, and academic achievement. However, the functional networks underlying individual differences in delay discounting during youth remain incompletely described. Here we investigate the association between multivariate patterns of functional connectivity and individual differences in impulsive choice in a large sample of youth. A total of 293 youth (9-23 years) completed a delay discounting task and underwent resting-state fMRI at 3T. A connectome-wide analysis using multivariate distance-based matrix regression was used to examine whole-brain relationships between delay discounting and functional connectivity was then performed. These analyses revealed that individual differences in delay discounting were associated with patterns of connectivity emanating from the left dorsal prefrontal cortex, a hub of the default mode network. Delay discounting was associated with greater functional connectivity between the dorsal prefrontal cortex and other parts of the default mode network, and reduced connectivity with regions in the dorsal and ventral attention networks. These results suggest that delay discounting in youth is associated with individual differences in relationships both within the default mode network and between the default mode and networks involved in attentional and cognitive control.

Pavlovian-to-Instrumental Transfer across Mental Disorders: A Review

A mechanism known as Pavlovian-to-instrumental transfer (PIT) describes a phenomenon by which the values of environmental cues acquired through Pavlovian conditioning can motivate instrumental behavior. PIT may be one basic mechanism of action control that can characterize mental disorders on a dimensional level beyond current classification systems. Therefore, we review human PIT studies investigating subclinical and clinical mental syndromes. The literature prevails an inhomogeneous picture concerning PIT. While enhanced PIT effects seem to be present in non-substance-related disorders, overweight people, and most studies with AUD patients, no altered PIT effects were reported in tobacco use disorder and obesity. Regarding AUD and relapsing alcohol-dependent patients, there is mixed evidence of enhanced or no PIT effects. Additionally, there is evidence for aberrant corticostriatal activation and genetic risk, e.g., in association with high-risk alcohol consumption and relapse after alcohol detoxification. In patients with anorexia nervosa, stronger PIT effects elicited by low caloric stimuli were associated with increased disease severity. In patients with depression, enhanced aversive PIT effects and a loss of action-specificity associated with poorer treatment outcomes were reported. Schizophrenic patients showed disrupted specific but intact general PIT effects. Patients with chronic back pain showed reduced PIT effects. We provide possible reasons to understand heterogeneity in PIT effects within and across mental disorders. Further, we strengthen the importance of reliable experimental tasks and provide test-retest data of a PIT task showing moderate to good reliability. Finally, we point toward stress as a possible underlying factor that may explain stronger PIT effects in mental disorders, as there is some evidence that stress per se interacts with the impact of environmental cues on behavior by selectively increasing cue-triggered wanting. To conclude, we discuss the results of the literature review in the light of Research Domain Criteria, suggesting future studies that comprehensively assess PIT across psychopathological dimensions.

Predicting smoking and nicotine dependence from the DSM-5 alternative model for personality pathology

Individuals with personality disorders (PDs) have higher morbidity and mortality than the general population, which may be due to maladaptive health behaviors such as smoking. Previous studies have examined the links between categorical PD diagnoses/personality traits and smoking/nicotine dependence, but little is known about how the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition alternative model for personality disorders relates to smoking and nicotine dependence. The current study examined this question in a sample of 500 participants using the Levels of Personality Functioning Scale to assess general personality pathology, the Personality Inventory for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition to measure specific traits, the Fagerström test for Nicotine Dependence to assess nicotine dependence, and questions about current and past smoking to assess smoking status (i.e., current, former, never). Multinomial logistic regression results demonstrated that general personality pathology (Criterion A) was not related to smoking status, and there were no reliable associations between traits (Criterion B) and smoking status. However, correlations showed that higher negative affectivity and disinhibition were related to higher levels of nicotine dependence within smokers. Findings are discussed in regard to previous findings linking personality pathology to smoking/nicotine dependence as well as the general validity of this new personality disorder diagnostic system. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A preliminary risk prediction model for cannabis use disorder

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Substance use disorders are currently a major public health crisis in the US.

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The prevalence of cannabis use disorder is rising due to legalization of cannabis.

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This study built models to predict the risk of cannabis use disorder for a user.

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Risk factors include personality traits, impulsivity and initial smoking enjoyment.

The ongoing trend toward legalization of cannabis for medicinal/recreational purposes is expected to increase the prevalence of cannabis use disorder (CUD). Thus, it is imperative to be able to predict the quantitative risk of developing CUD for a cannabis user based on their personal risk factors. Yet no such model currently exists. In this study, we perform preliminary analysis toward building such a model. The data come from n = 94 regular cannabis users recruited from Albuquerque, New Mexico during 2007–2010. As the data are cross-sectional, we only consider risk factors that remain relatively stable over time. We apply statistical and machine learning classification techniques that allow n to be small relative to the number of predictors. We use predictive accuracy estimated using leave-one-out-cross-validation to evaluate model performance. The final model is a LASSO logistic regression model consisting of the following seven risk factors: age; level of enjoyment from initial cigarette smoking; total score on Impulsive Sensation-Seeking Scale questionnaire; score on cognitive instability factor of Barratt Impulsivity Scale questionnaire; and scores on neuroticism, openness, and conscientiousness personality traits of Neuroticism, Extraversion, and Openness inventory. This model has an overall accuracy of 0.66 and the area under its receiver operating characteristic curve is 0.65. In summary, a preliminary relative risk model for predicting the quantitative risk of CUD is developed. It can be employed to identify users at high risk of CUD who may be provided with early intervention.

Predictors of reduced smoking quantity among recovering alcohol dependent men in a smoking cessation trial

INTRODUCTION

Adults with alcohol dependence (AD) have exceptionally high smoking rates and poor smoking cessation outcomes. Discovery of factors that predict reduced smoking among AD smokers may help improve treatment. This study examined baseline predictors of smoking quantity among AD smokers in a pharmacotherapy trial for smoking cessation.

METHODS

The sample includes male, AD smokers (N = 129) with 1-32 months of alcohol abstinence who participated in a 12-week trial of medication (topiramate vs. placebo) and adjunct counseling with 6 months of follow-up. Baseline measures of nicotine dependence, AD severity, psychopathology, motivation to quit smoking, and smoking-related cognitions were used to predict smoking quantity (cigarettes per day) at post-treatment and follow-up.

RESULTS

Overall, the sample had statistically significant reductions in smoking quantity. Greater nicotine dependence (Incidence rate ratios (IRRs) = 0.82-0.90), motivation to quit (IRRs = 0.65-0.85), and intrinsic reasons for quitting (IRRs = 0.96-0.98) predicted fewer cigarettes/day. Conversely, greater lifetime AD severity (IRR = 1.02), depression severity (IRRs = 1.05-1.07), impulsivity (IRRs = 1.01-1.03), weight-control expectancies (IRRs = 1.10-1.15), and childhood sexual abuse (IRRs = 1.03-1.07) predicted more cigarettes/day.

CONCLUSIONS

Smokers with AD can achieve large reductions in smoking quantity during treatment, and factors that predict smoking outcomes in the general population also predict greater smoking reductions in AD smokers. Treatment providers can use severity of nicotine dependence and AD, motivation to quit, smoking-related cognitions, and severity of depression to guide treatment and improve outcomes among AD smokers.

Smoking Cessation for Those Pursuing Recovery from Substance Use Disorders

This article summarizes the literature regarding the similar biopsychosocial mechanisms of tobacco use and alcohol and substance use disorders, and the evidence for and against the provision of tobacco cessation for those in treatment for alcohol and substance use disorders. The practicality of treatment, focusing on methods, timing, and breadth of intervention strategies, are also presented. Common methodologies that may be used across tobacco use and alcohol and substance use disorder to prevent lapse and relapse are discussed. Physicians can and should adhere to the policy that tobacco use is a common and dangerous comorbid condition that demands concomitant treatment.

Impulsivity related personality traits and cigarette smoking in adults: A meta-analysis using the UPPS-P model of impulsivity and reward sensitivity

BACKGROUND

Although there is considerable evidence of an association between impulsivity and cigarette smoking, the magnitude of this association varies across studies. Impulsivity comprises several discrete traits that may influence cigarette use in different ways. The present meta-analysis aims to examine the direction and magnitude of relationships between specific impulsivity-related traits, namely lack of premeditation, lack of perseverance, sensation seeking, negative urgency, positive urgency and reward sensitivity and both smoking status and severity of nicotine dependence in adults across studies and to delineate differences in effects across these relationships.

METHODS

Ninety-seven studies were meta-analysed using random-effects models to examine the relationship between impulsivity-related traits and smoking status and severity of nicotine dependence. A number of demographic and methodological variables were also assessed as potential moderators.

RESULTS

Smoking status and severity of nicotine dependence were significantly associated with all impulsivity-related traits except reward sensitivity. Lack of premeditation and positive urgency showed the largest associations with smoking status (r = 0.20, r = 0.24 respectively), while positive urgency showed the largest association with severity of nicotine dependence (r = 0.23). Study design moderated associations between lack of premeditation and lack of perseverance and smoking status, with larger effects found in cross-sectional compared to prospective studies.

CONCLUSIONS

Finding suggest that impulsivity is associated with an increased likelihood of being a smoker and greater nicotine dependence. Specific impulsivity-related traits differentially relate to smoking status and severity of nicotine dependence. Understanding the complexity of impulsivity-related traits in relation to smoking can help to identify potential smokers and could inform cessation treatment.

Early age of e-cigarette use onset mediates the association between impulsivity and e-cigarette use frequency in youth

BACKGROUND

Identifying risk factors for youth e-cigarette use is critical, given high rates of e-cigarette use and unknown health effects of long-term use. The current study examined whether an early age of onset of e-cigarette use mediates the association between impulsivity and e-cigarette frequency.

METHODS

Cross-sectional survey data of e-cigarette users (n=927) were collected from 8 high schools in southeastern Connecticut. The sample was 44.7% female (mean age 16.2 [SD=1.2], mean age of e-cigarette onset 14.7 [SD=1.6]). Two domains of self-reported, trait impulsivity were assessed using the abbreviated Barratt Impulsiveness Scale: impaired self-regulation (e.g., problems with concentration or self-control) and behavioral impulsivity (e.g., doing things without thinking). Mediation was tested with Mplus, and the model included school as a cluster variable and controlled for covariates related to e-cigarette use (i.e., sex, age, race, peer use, and other tobacco products ever tried).

RESULTS

The hypothesized mediation was supported for both domains of impulsivity (impaired self-regulation a₁b=0.09, SE=0.02, 95%CI [0.03-0.14], p=.002; behavioral impulsivity a₂b=0.07, SE=0.03, 95%CI [.01-.14], p=0.03). Specifically, impaired self-regulation (B=-0.33, SE=0.06, p<0.001) and behavioral impulsivity (B=-0.26, SE=0.11, p=0.02) predicted trying e-cigarettes at an earlier age, and earlier initiation was associated with more days of e-cigarette use in the past month (B=-0.28, SE=0.08, p<0.001).

CONCLUSIONS

Adolescents who endorse aspects of impulsivity, such as acting without thinking, are at greater risk for more frequent e-cigarette use through an early age of e-cigarette initiation. Further research is needed to evaluate these relationships longitudinally and to develop targeted e-cigarette interventions for impulsive youth.

nAChR dysfunction as a common substrate for schizophrenia and comorbid nicotine addiction: Current trends and perspectives

INTRODUCTION

The prevalence of tobacco use in the population with schizophrenia is enormously high. Moreover, nicotine dependence is found to be associated with symptom severity and poor outcome in patients with schizophrenia. The neurobiological mechanisms that explain schizophrenia-nicotine dependence comorbidity are not known. This study systematically reviews the evidence highlighting the contribution of nicotinic acetylcholine receptors (nAChRs) to nicotine abuse in schizophrenia.

METHODS

Electronic data bases (Medline, Google Scholar, and Web of Science) were searched using the selected key words that match the aims set forth for this review. A total of 276 articles were used for the qualitative synthesis of this review.

RESULTS

Substantial evidence from preclinical and clinical studies indicated that dysregulation of α7 and β2-subunit containing nAChRs account for the cognitive and affective symptoms of schizophrenia and nicotine use may represent a strategy to remediate these symptoms. Additionally, recent meta-analyses proposed that early tobacco use may itself increase the risk of developing schizophrenia. Genetic studies demonstrating that nAChR dysfunction that may act as a shared vulnerability factor for comorbid tobacco dependence and schizophrenia were found to support this view. The development of nAChR modulators was considered an effective therapeutic strategy to ameliorate psychiatric symptoms and to promote smoking cessation in schizophrenia patients.

CONCLUSIONS

The relationship between schizophrenia and smoking is complex. While the debate for the self-medication versus addiction vulnerability hypothesis continues, it is widely accepted that a dysfunction in the central nAChRs represent a common substrate for various symptoms of schizophrenia and comorbid nicotine dependence.

Longitudinal Associations among Impulsivity, Friend Substance Use, and Adolescent Substance Use

Adolescent substance use is an increasing problem in the United States, and some researchers posit a bidirectional relation between adolescent substance use and the personality trait of impulsivity (e.g., Quinn, Stappenbeck, & Fromme, 2011). Friend substance use has been shown to be a powerful predictor of adolescent substance use, with prior research suggesting a bidirectional relation between adolescent substance use and friend substance use (e.g., Simons-Morton & Chen, 2006). Extant literature has not tested the bidirectional relation between adolescent substance use and impulsivity with longitudinal data nor has it examined this relation while considering the bidirectional relation with the social context factor of friend substance use. Using three waves of longitudinal data, we tested if there was a bidirectional relation between adolescent substance use and impulsivity while also examining the influences of friend substance use. Participants were 131 adolescents (male = 55%, mean age = 13 years at Wave 1). We tested nested models and examined whether adding equality constraints degraded the model fit using a Wald test. Results of structural equation modeling indicated that, after controlling for baseline levels of substance use, impulsivity predicted adolescent and friend substance use over time, whereas adolescent and friend substance use did not predict impulsivity. Adolescents with substance using friends were likely to increase their own substance use. The findings imply that aiming at both improving adolescents’ ability to regulate impulsivity and deterring associations with friends who are using substances is essential for prevention and intervention efforts against substance use development in adolescents.

Performance of Smokers with DSM-5 Tobacco Use Disorder in Time-Based Complex Prospective Memory

Studies that investigate time-based complex prospective memory (PM) functioning in participants with substance use disorders (SUD) in consideration of different PM-phases (planning, retention, initiation, execution) are lacking. This study was designed to investigate performance of young adults with DSM-5 tobacco use disorder (TUD) and healthy controls (HC) in different phases of complex PM. Community participants aged 18-35 (N=43) completed the modified Six Elements Test that includes the PM-phases planning, retention, initiation, and execution of a time-based complex PM-task (with delay phases and background activities). TUD participants were current daily smokers and fulfilled at least two DSM-5 TUD criteria. TUD did not differ significantly from HC in task planning errors and timely task initiation. No group differences showed in rule adherence and completeness during task conduction (execution). During execution, TUD showed significantly more deviations (Coef. 0.45; p=0.005) from their originally remembered plans than HC. Young adults with relatively mild TUD do not show general impairments in all phases of short-term, complex, and time-based PM. Future research may investigate whether a greater risk of deviation from originally remembered plans in TUD could play a role in the progression and cessation of smoking behavior.

Delay discounting rates: a strong prognostic indicator of smoking relapse

BACKGROUND

Recent evidence suggests that several dimensions of impulsivity and locus of control are likely to be significant prognostic indicators of relapse.

METHOD

One-hundred and thirty-one treatment seeking smokers were enrolled in six weeks of multi-component cognitive-behavioral therapy with eight weeks of nicotine replacement therapy.

ANALYSIS

Cox proportional hazard regressions were used to model days to relapse with each of the following: delay discounting of $100, delay discounting of $1000, six subscales of the Barratt Impulsiveness Scale (BIS), Rotter's Locus of Control (RLOC), Fagerstrom's Test for Nicotine Dependence (FTND), and the Perceived Stress Scale (PSS). Hazard ratios for a one standard deviation increase were estimated with 95% confidence intervals for each explanatory variable. Likelihood ratios were used to examine the level of association with days to relapse for different combinations of the explanatory variables while accounting for nicotine dependence and stress level.

RESULTS

These analyses found that the $100 delay discounting rate had the strongest association with days to relapse. Further, when discounting rates were combined with the FTND and PSS, the associations remained significant. When the other measures were combined with the FTND and PSS, their associations with relapse non-significant.

CONCLUSIONS

These findings indicate that delay discounting is independently associated with relapse and adds to what is already accounted for by nicotine dependence and stress level. They also signify that delay discounting is a productive new target for enhancing treatment for tobacco dependence. Consequently, adding an intervention designed to decrease discounting rates to a comprehensive treatment for tobacco dependence has the potential to decrease relapse rates.

Unique aspects of impulsive traits in substance use and overeating: specific contributions of common assessments of impulsivity

Abstract Background: Impulsivity is a complex trait often studied in substance abuse and overeating disorders, but the exact nature of impulsivity traits and their contribution to these disorders are still debated. Thus, understanding how to measure impulsivity is essential for comprehending addictive behaviors.

OBJECTIVES

Identify unique impulsivity traits specific to substance use and overeating.

METHODS

Impulsive Sensation Seeking (ImpSS) and Barratt's Impulsivity scales (BIS) Scales were analyzed with a non-parametric factor analytic technique (discriminant correspondence analysis) to identify group-specific traits on 297 individuals from five groups: Marijuana (n = 88), Nicotine (n = 82), Overeaters (n = 27), Marijuauna + Nicotine (n = 63), and CONTROLs (n = 37).

RESULTS

A significant overall factor structure revealed three components of impulsivity that explained respectively 50.19% (pperm < 0.0005), 24.18% (pperm < 0.0005), and 15.98% (pperm < 0.0005) of the variance. All groups were significantly different from one another. When analyzed together, the BIS and ImpSS produce a multi-factorial structure that identified the impulsivity traits specific to these groups. The group specific traits are (1) CONTROL: low impulse, avoids thrill-seeking behaviors; (2) Marijuana: seeks mild sensation, is focused and attentive; (3) Marijuana + Nicotine: pursues thrill-seeking, lacks focus and attention; (4) Nicotine: lacks focus and planning; (5) Overeating: lacks focus, but plans (short and long term).

CONCLUSIONS

Our results reveal impulsivity traits specific to each group. This may provide better criteria to define spectrums and trajectories - instead of categories - of symptoms for substance use and eating disorders. Defining symptomatic spectrums could be an important step forward in diagnostic strategies.

The intergenerational transmission of smoking in adulthood: a 25-year study of maternal and offspring maladaptive attributes

While smoking is a major cause of mortality and morbidity, and maternal smoking is a risk factor for smoking among their offspring, the mechanisms involved in the intergenerational transmission of smoking are not well understood. This study examines the pathways from maternal and adolescent child factors, and the parent-child relationship, to smoking among the adult offspring, approximately 25 years later. Data for the present analysis were based on time waves 2 (T2; 1983) and 7 (T7; 2007-2009) of an on-going study of a community sample of mothers and their children. Offspring and mother X¯ ages were 14.1 and 40.0 years, respectively, at T2, and 36.6 and 65.0 years, respectively, at T7. At T2, trained interviewers administered individual structured interviews. Psychosocial questionnaires were self-administered at T7. Structural equation modeling (SEM) was used to analyze the interrelationships among maternal and offspring attributes (T2 and T7). SEM results indicated a satisfactory model fit (RMSEA=0.052; CFI=0.91; SRMR=0.057), and confirmed hypothesized pathways. One pathway linked maternal maladaptive attributes (T2) to the mother-adolescent child attachment relationship (T2), which was associated with the offspring's maladaptive attributes over time (T2 to T7), which then predicted the adult offspring's smoking (T7). Other pathways highlighted the stability of maternal smoking, the continuity of maladaptive attributes, and less offspring educational attainment as predictors of offspring smoking at T7. Findings suggest the importance of early interventions to treat maternal smoking, maternal and offspring maladaptive attributes, and the mother-child relationship in order to reduce risk factors for the intergenerational transmission of smoking behavior. Interventions which enhance educational success should also prove effective in reducing smoking.

The relationship between impulsivity, risk-taking propensity and nicotine dependence among older adolescent smokers

Impulsivity and risk-taking propensity are neurobehavioral traits that reliably distinguish between smoking and non-smoking adults. However, how these traits relate to smoking quantity and nicotine dependence among older adolescent smokers is unclear. The current study examined impulsivity and risk-taking propensity in relation to smoking behavior and nicotine dependence among current older adolescent smokers (age 16-20 years; N=107). Participants completed the Barratt Impulsiveness Scale-11 (BIS-11), the Balloon Analogue Risk Task (BART), and self-report measures of smoking behavior and nicotine dependence. Results indicated a significant positive relationship between nicotine dependence and the Attention subscale (β=.20, t=2.07, p<.05) and the Non-planning subscale (β=.19, t=1.92, p<.06) of the BIS-11. Contrary to expectation, the results also indicated a significant negative relationship between performance on the BART and nicotine dependence (β=-.19, t=-2.18, p<.05), such that greater risk-taking propensity was associated with less dependence. These data suggest that impulsivity and risk-taking propensity are related to older adolescent smoking but are separable traits with distinguishable associations with nicotine dependence among adolescents. These findings support the notion that impulsivity is related to heightened nicotine dependence, but suggest that the relationship between risk-taking propensity and nicotine dependence is more ambiguous and warrants further investigation.

Associations of functional and dysfunctional impulsivity to smoking characteristics

OBJECTIVES

Although the relation between impulsivity and smoking is well-documented, one model of impulsivity that has received little attention in the addiction literature separates impulsivity into 2 dimensions: functional impulsivity (tendency to make quick effective decisions) and dysfunctional impulsivity (tendency to make quick ineffective decisions).

METHODS

This cross-sectional study examined relations of functional and dysfunctional impulsivity to smoking characteristics in 212 non-treatment-seeking daily smokers (M = 15 cigarettes per day, M age = 24 years, 53% women).

RESULTS

Dysfunctional impulsivity exhibited small- to medium-sized positive associations with difficulty refraining from smoking in forbidden places, craving, and smoking without awareness. Functional impulsivity was inversely associated with a measure of cigarette craving. Other suggestive associations were found; however, these were not statistically significant after type I error correction.

CONCLUSIONS

Although the overall predictive validity of these impulsivity constructs for explaining variance in smoking characteristics was relatively modest, the results suggest that conceptualizing impulsivity as a unitary construct indicative of a tendency to make quick decisions may mask heterogeneity within the impulsivity-smoking relationship. These findings suggest that high-dysfunctional impulsivity smokers may perhaps require more intensive interventions to dampen motivation to smoke. They also highlight the possibility that certain manifestations of impulsivity are not related with increased smoking behavior and may actually associate with reduced drive to smoke.

The role of impulsivity in the aetiology of drug dependence: reward sensitivity versus automaticity

RATIONALE

Impulsivity has long been known as a risk factor for drug dependence, but the mechanisms underpinning this association are unclear. Impulsivity may confer hypersensitivity to drug reinforcement which establishes higher rates of instrumental drug-seeking and drug-taking behaviour, or may confer a propensity for automatic (non-intentional) control over drug-seeking/taking and thus intransigence to clinical intervention.

METHOD

The current study sought to distinguish these two accounts by measuring Barratt Impulsivity and craving to smoke in 100 smokers prior to their completion of an instrumental concurrent choice task for tobacco (to measure the rate of drug-seeking) and an ad libitum smoking test (to measure the rate of drug-taking-number of puffs consumed).

RESULTS

The results showed that impulsivity was not associated with higher rates of drug-seeking/taking, but individual differences in smoking uptake and craving were. Rather, nonplanning impulsivity moderated (decreased) the relationship between craving and drug-taking, but not drug-seeking.

CONCLUSIONS

These data suggest that whereas the uptake of drug use is mediated by hypervaluation of the drug as an instrumental goal, the orthogonal trait nonplanning impulsivity confers a propensity for automatic control over well-practiced drug-taking behaviour.