Differences in self-reported and behavioral measures of impulsivity in recreational and dependent cocaine users

Background

Dependent cocaine users consistently display increased trait impulsivity on self-report questionnaires and less consistently exhibit elevated motor impulsivity in some behavioral tasks. However, trait and behavioral impulsivity measures have rarely been investigated in recreational users. Therefore, we examined self-reported trait and motor impulsivities in recreational and dependent cocaine users to clarify the role of impulse control in cocaine addiction and non-dependent cocaine use.

Methods

We investigated relatively pure recreational (n = 68) and dependent (n = 30) cocaine users, as well as psychostimulant-naïve controls (n = 68), with self-report questionnaires (Barratt Impulsiveness Scale 11; Temperament and Character Inventory) and behavioral tasks (Rapid Visual Information Processing Task; Stop-Signal Task).

Results

Compared with controls, recreational and dependent cocaine users displayed higher trait impulsivity and novelty seeking scores on self-report questionnaires. Trait impulsivity scores were strongly associated with an increased number of symptoms of depression and attention deficit hyperactivity disorder and correlated significantly with long-term cocaine intake parameters. By contrast, none of the behavioral motor impulsivity measures showed significant group effects or correlated with cocaine use parameters. The correlations among the self-report measures were high, but self-reports were scarcely correlated with behavioral task measures.

Conclusions

These findings suggest that relatively pure cocaine users already display increased trait impulsivity at a recreational level of use. However, the results do not indicate any cocaine-related elevation of behavioral impulsivity in terms of motor or response inhibition. In summary, our data imply that elevated trait impulsivity is not a specific feature of dependent cocaine use.     

Impulsivity and substance-related attentional bias: A meta-analytic review

Background

Previous research demonstrates the role of attentional bias in addictive behaviors. Impulsivity is thought to affect the strength of attentional biases, and thus, attentional biases might be one mechanism by which impulsivity affects addictive behaviors. However, whether or not impulsivity is related to attentional biases across different conceptualizations of impulsivity and attentional biases has yet to be examined as an initial test of such causal models.

Methods

The authors completed a meta-analysis of 13 published research studies examining the relationship between substance-related attentional bias and different conceptualizations of impulsivity.

Results

There was a small and significant effect size between impulsivity and substance-related attentional bias (r = 0.20), which was moderated by impulsivity measurement type (Q_b = 5.91, df = 1, p < 0.05): there was a stronger relationship between behavioral impulsivity and substance-related attentional bias (r = 0.22) than trait impulsivity and substance-related attentional bias (r = 0.10). Different components of behavioral impulsivity and trait impulsivity did not affect the relationship.

Conclusions

This study is the first systematic and empirical demonstration of the relationship between substance-related attentional bias and impulsivity and suggests viability of future examinations of casual models relating these constructs. Since trait and behavioral conceptualizations differentially relate to substance-related attentional bias, the current review further supports research suggesting how disaggregation of multidimensional constructs can lead to more robust relationships.     

Associations among types of impulsivity, substance use problems and neurexin-3 polymorphisms

Background

Some of the genetic vulnerability for addiction may be mediated by impulsivity. This study investigated relationships among impulsivity, substance use problems and six neurexin-3 (NRXN3) polymorphisms. Neurexins (NRXNs) are presynaptic transmembrane proteins that play a role in the development and function of synapses.

Methods

Impulsivity was assessed with the Barratt Impulsiveness Scale Version 11 (BIS-11), the Boredom Proneness Scale (BPS) and the TIME paradigm; alcohol problems with the Michigan Alcoholism Screening Test (MAST); drug problems with the Drug Abuse Screening Test (DAST-20); and regular tobacco use with a single question. Participants (n = 439 Caucasians, 64.7% female) donated buccal cells for genotyping. Six NRXN3 polymorphisms were genotyped: rs983795, rs11624704, rs917906, rs1004212, rs10146997 and rs8019381. A dual luciferase assay was conducted to determine whether allelic variation at rs917906 regulated gene expression.

Results

In general, impulsivity was significantly higher in those who regularly used tobacco and/or had alcohol or drug problems. In men, there were modest associations between rs11624704 and attentional impulsivity (p = 0.005) and between rs1004212 and alcohol problems (p = 0.009). In women, there were weak associations between rs10146997 and TIME estimation (p = 0.03); and between rs1004212 and drug problems (p = 0.03). The dual luciferase assay indicated that C and T alleles of rs917906 did not differentially regulate gene expression in vitro.

Conclusions

Associations between impulsivity, substance use problems and polymorphisms in NRXN3 may be gender specific. Impulsivity is associated with substance use problems and may provide a useful intermediate phenotype for addiction.     

Internal mouthpiece designs as a future perspective for enhanced aerosol deposition. Comparative results for aerosol chemotherapy and aerosol antibiotics

Background

In an effort to identify factors producing a finest mist from Jet-Nebulizers we designed 2 mouthpieces with 4 different internal designs and 1–3 compartments.

Materials and methods

Ten different drugs previous used with their “ideal” combination of jet-nebulizer, residual-cup and loading were used. For each drug the mass median aerodynamic diameter size had been established along with their “ideal” combination.

Results

For both mouthpiece, drug was the most important factor due the high F-values (F_large = 251.7, p < 0.001 and F_small = 60.1, p < 0.001) produced. The design affected the droplet size but only for large mouthpiece (F_large = 5.99, p = 0.001, F_small = 1.72, p = 0.178). Cross designs create the smallest droplets (2.271) so differing from the other designs whose mean droplets were greater and equal ranging between 2.39 and 2.447. The number of compartments in the two devices regarding the 10 drugs was found not statistically significant (p-values 0.768 and 0.532 respectively). Interaction effects between drugs and design were statistically significant for both devices (F_large = 8.87, p < 0.001, F_small = 5.33, p < 0.001).

Conclusion

Based on our experiment we conclude that further improvement of the drugs intended for aerosol production is needed. In addition, the mouthpiece design and size play an important role in further enhancing the fine mist production and therefore further experimentation is needed.     

Young adult waterpipe smokers: Smoking behaviors and associated subjective and physiological effects

Introduction

The purpose of this pilot study was to investigate smoking behaviors and subjective and physiological effects of nicotine on young adult occasional waterpipe smokers.

Methods

This study utilized a repeated-measures design that included one repeated factor for condition (nicotine and non-nicotine). For each participant, the sequencing of the repeated factor was assigned using random allocation. The two nicotine conditions were nicotine (0.75 g) and non-nicotine (0 g placebo) tobacco. Over the course of two weeks, twenty-two participants completed subjective (Acute Subjective Effects of Nicotine) and physiological (blood pressure, heart rate, and CO level) measures. Additional measures (QSU and MNWS-R) were used to assess for withdrawal symptoms.

Sample

The participants (n = 22) were young adults (23 ± 3.1 years); 71% smoked waterpipe once a month in the past year and 29% smoked waterpipe 1–2 times per week. In addition, 60% reported sharing their waterpipe with friends while smoking. None of the participants reported using any other forms of tobacco products.

Results

Under the nicotine condition, participants tended to smoke longer (i.e. smoking duration, p = 0.004), take more puffs (p = 0.03), take shorter puffs (p = 0.03), and inhale less volume with each puff (p = 0.02). The repeated measures analysis of the factor headrush revealed an effect of the nicotine condition (F = 9.69, p < 0.001, partial η² = 0.31) and time (F = 8.17, p = 0.02, partial η² = 0.30). Heart rate increased significantly across the nicotine condition (F = 7.92, p = 0.01, partial η² = 0.31) and over time (F = 12.64, p = 0.01, partial η² = 0.41).

Conclusions

This study demonstrates how differences between nicotine and non-nicotine waterpipe smoking are associated with changes in smoking behaviors, experiencing a headrush and an increase in heart rate.     

Establishing the optimal nebulization system for paclitaxel,docetaxel, cisplatin,carboplatin and gemcitabine: Back to drawing the residual cup

Background

Chemotherapy drugs have still the major disadvantage of non-specific cytotoxic effects. Although, new drugs targeting the genome of the tumor are already in the market, doublet chemotherapy regimens still remain the cornerstone of lung cancer treatment. Novel modalities of administration are under investigation such as; aerosol, intratumoral and intravascular.

Materials and methods

In the present study five chemotherapy drugs; paclitaxel, docetaxel, gemcitabine, carboplatin and cisplatin were nebulized with three different jet nebulizers (Maxineb^®, Sunmist^®, Invacare^®) and six different residual cups at different concentrations. The purpose of the study was to identify the “ideal” combination of nebulizer-residual cup design-drug–drug loading for a future concept of aerosol chemotherapy in lung cancer patients. The Mastersizer^® 2000 was used to evaluate the aerosol droplet mass median aerodynamic diameter.

Results

The drug, nebulizer and residual cup design greatly influences the producing droplet size (p < 0.005, in each case). However; the design of the residual cup is the most important factor affecting the produced droplet size (F = 834.6, p < 0.001). The drug loading plays a vital role in the production of the desired droplet size (F = 10.42, p < 0.001). The smallest droplet size was produced at 8 ml loading (1.26 μm), while it remained the same at 2, 4 and 6 mls of drug loading.

Conclusion

The ideal nebulizer would be Maxineb^®, with a large residual cup (10 ml maximum loading capacity) and 8 mls loading and the drug with efficient pulmonary deposition would be docetaxel.     

Associations between behavioral disinhibition and cocaine use history in individuals with cocaine dependence

Background

Behavioral disinhibition has been suggested as both a cause and consequence of substance use disorders. Many studies examining associations between behavioral disinhibition and substance use history have focused on individuals with alcohol dependence or non-dependent college students. In the present study, the relationship between behavioral disinhibition and cocaine use history in individuals with cocaine dependence is examined.

Methods

Forty-six non-treatment-seeking cocaine-dependent men and women completed impulsivity (Barratt Impulsiveness Scale; BIS) and novelty seeking (Temperament and Character Inventory; TCI) questionnaires at the baseline visit of an ongoing study. Unadjusted, and adjusted for gender and age, Pearson correlations were calculated between BIS, TCI, and cocaine use variables from the Structured Clinical Interview for DSM-IV and Timeline Follow-back (age of onset, quantity/frequency of past 30 day cocaine use).

Results

As expected, elevated motor impulsivity and novelty seeking were each associated with younger age of dependence onset. Also, individuals with lower levels of persistence on the TCI reported more days of cocaine use over the previous month. Unexpectedly, increased novelty seeking and attentional impulsivity were associated with fewer days of cocaine use and less money spent on cocaine, respectively. Controlling for age and gender did not substantially change the pattern of observed associations.

Conclusions

The present study provides preliminary evidence for associations between behavioral disinhibition and cocaine use history in cocaine-dependent individuals. Given our relatively small sample size and the correlational nature of our findings, further research is needed to replicate and extend our results.     

A tale of two stimulants: Mentholated cigarettes may play a role in cocaine,but not methamphetamine,dependence

Background

Research suggests that mentholated cigarettes may play a role in cocaine dependence. The purpose of the present study was to expand upon the research on mentholated cigarettes and cocaine dependence and to evaluate the role of mentholated cigarettes in methamphetamine dependence.

Methods

Secondary analysis of a multisite, randomized trial evaluating the impact of smoking-cessation treatment in stimulant-dependent outpatients (N = 538). Participants’ reasons for concurrent use of cigarettes and illicit stimulants were assessed via self-report. Stimulant-abstinence was measured by self-report and urine drug screens. Smoking cessation was assessed via self-report and carbon monoxide levels.

Results

Of the 301 cocaine-dependent participants, 201 (67%) were menthol and 100 (33%) were non-menthol cigarette smokers. Cocaine-dependent participants who smoked menthol, compared to non-menthol, cigarettes were significantly more likely to report that cigarettes prolong their cocaine high (X²(1) = 16.3, p < .0001, OR = 3.58 [95% CI: 1.88–6.79]) and were less likely to be stimulant abstinent during active treatment (W = 3.6, p < 0.001, d = .39 [95% CI: 0.16–0.62]), at 3-month follow-up (X²(1) = 14.4, p < 0.001, OR = .32 [95% CI: 0.17–0.58]), and at 6-month follow-up (X²(1) = 4.6, p = 0.03, OR = .53 [95% CI: 0.29–0.95]). No parallel differences were found between menthol and non-menthol methamphetamine-dependent smokers. The prevalence of Caucasian menthol smokers was significantly greater in the cocaine-dependent participants (37.2%) than in the methamphetamine-dependent participants (17.61%), (X²(1) = 14.4, p < .001, OR = 2.77 [95% CI:1.62–4.73]). Smoking cessation was not significantly associated with cigarette type for either cocaine- or methamphetamine-dependent participants.

Conclusions

The present results suggest that mentholated cigarettes play a role in cocaine, but not methamphetamine, dependence.     

Positive smoker identity as a barrier to quitting smoking: Findings from a national survey of smokers in England

Background

It has been proposed that positive smoker identity may be an important factor undermining smoking cessation but very little research exists on this. This study tested the hypothesis that a simple measure of positive smoker identity would predict quit attempts over and above other known predictors in a population sample. More tentatively it explored whether this measure would also predict quit success.

Methods

A representative sample of adult smokers in England (n = 9456) was included at baseline and 2099 were followed-up at six months. Demographic and smoking characteristics, a single item measure of positive smoker identity (endorsing the statement: ‘I like being a smoker’), measures of smoking-related attitudes, quit attempts and quit success were included.

Results

A total of 18.3% (95% CI = 17.5–19.2) of smokers reported a positive smoker identity. Adjusting for all other predictors, those with a positive smoker identity were more likely to be older (p < 0.001), male (p = 0.013), more nicotine dependent (p < 0.001), have lower motivation to stop (p < 0.001), have not made a quit attempt in the past year (p = 0.025), enjoy smoking (p < 0.001), and consider themselves to be addicted (p < 0.001). Having a positive smoker identity independently predicted failure to make a quit attempt at six months (p = 0.007). The independent association with quit success was similar in magnitude but did not reach statistical significance (p = 0.053).

Conclusions

Only a minority of smokers in England have a positive smoker identity. However, where it is present it may be an important barrier to quitting smoking and merits further study.     

Reinforcing integrated psychiatric service attendance in an opioid-agonist program: A randomized and controlled trial

Background

The benefits of integrating substance abuse and psychiatric care may be limited by poor service utilization. This randomized clinical trial evaluated the efficacy of using contingency management to improve utilization of psychiatric services co-located and integrated within a community-based methadone maintenance treatment program.

Methods

Opioid-dependent outpatients (n = 125) with any current psychiatric disorder were randomly assigned to: (1) reinforced on-site integrated care (ROIC), with vouchers (worth $25.00) contingent on full adherence to each week of scheduled psychiatric services; or (2) standard on-site integrated care (SOIC). All participants received access to the same schedule of psychiatrist and mental health counseling sessions for 12-weeks.

Results

ROIC participants attended more overall psychiatric sessions at month 1 (M = 7.53 vs. 3.97, p < .001), month 2 (M = 6.31 vs. 2.81, p < .001), and month 3 (M = 5.71 vs. 2.44, p < .001). Both conditions evidenced reductions in psychiatric distress (p < .001) and similar rates of drug-positive urine samples. No differences in study retention were observed.

Conclusions

These findings suggest that contingency management can improve utilization of psychiatric services scheduled within an on-site and integrated treatment model. Delivering evidenced-based mental health counseling, or modifying the contingency plan to include illicit drug use, may be required to facilitate greater changes in psychiatric and substance abuse outcomes.     

Understanding the role of cessation fatigue in the smoking cessation process

Background

To understand the dynamic process of cessation fatigue (i.e., the tiredness of trying to quit smoking) with respect to its average trend, effect on relapse, time-varying relations with craving and negative affect, and differences among genders and treatment groups.

Method

Randomized placebo-controlled clinical trial. Participants received either placebo, monotherapy (bupropion SR, nicotine patch, nicotine lozenge), or combined pharmacotherapy (bupropion SR + nicotine lozenge, nicotine patch + nicotine lozenge). Data were collected from 1504 daily smokers who were motivated to quit smoking. The participants completed baseline assessments and ecological momentary assessments for 2 weeks post-quit.

Results

Cessation fatigue reduced the likelihood of 6-month post-quit abstinence (OR = 0.97, 95% CI (0.95, 0.99)), and was positively associated with craving and negative affect. After controlling for these two factors, average cessation fatigue increased over time. Compared to men, women experienced greater fatigue (t = −10.69, p < 0.0001) and a stronger relation between fatigue and craving (t = −8.80, p < 0.0001). The relationship between fatigue and negative affect was significantly stronger in men (t = 5.73, p < 0.0001). Cessation fatigue was significantly reduced by combined pharmacotherapy (t = −13.4, p < 0.0001), as well as monotherapy (t = −6.2, p < 0.0001).

Conclusions

Cessation fatigue was closely related to craving, negative affect, and cessation outcomes. Women reported greater cessation fatigue than men. Current treatments appeared to reduce fatigue and weaken its relations with craving and negative affect.     

Intentions to quit smoking among youth in substance abuse treatment

Introduction

Smoking cessation interventions for adolescents in substance abuse treatment have shown promise. However, a better understanding of the correlates of substance use disordered (SUD) youths’ intentions toward smoking cessation will help tailor cessation interventions to this population. The current study examined tobacco use, smoking-related self-efficacy, substance use and intentions to quit using alcohol and illicit drugs as correlates of intentions to quit smoking among youth in SUD treatment.

Methods

Participants were 178 adolescents who were in inpatient (n = 90) or outpatient (n = 88) SUD treatment and had smoked at least once in the past 30 days. The sample was 44% female, 72% non-Hispanic Caucasian, with a mean age of 16.2 years (SD = 1.2). Participants rated the likelihood that they would be nonsmokers in the next year (9-point scale).

Results

SUD youth intention to quit smoking averaged 4.9 out of 10 (SD = 3.2), comparable to intention to quit drinking (M = 5.3, SD = 3.6), but lower than their intention to quit using drugs (M = 6.0, SD = 3.4). Teens’ intentions to quit smoking were associated with nicotine dependence (r = −.30, p < .01) and smoking cessation related self-efficacy (r = .36, p < .01), but not with pretreatment substance use severity (r = −.15). Controlling for nicotine dependence, teens’ intentions to quit smoking were positively related to smoking cessation self-efficacy (pr = .26, p < .01) and intention to quit using illicit drugs (pr = .15, p < .05), but unrelated to intention to quit drinking.

Discussion

Findings highlight the appropriateness of addressing adolescent tobacco use during SUD treatment, but emphasize the importance of assessing intention and other cognitions for each substance, as they may differ markedly.     

Randomized clinical trial examining duration of voucher-based reinforcement therapy for cocaine abstinence

Background

This is the first study to systematically manipulate duration of voucher-based reinforcement therapy (VBRT) to see if extending the duration increases abstinence during and following VBRT.

Methods

We randomized cocaine-dependent methadone-maintained adults to Standard (12 weeks; n = 62) or Extended (36 weeks; n = 68) VBRT and provided escalating voucher amounts contingent upon urinalysis verification of cocaine abstinence. Urinalysis was scheduled at least every 2 weeks during the 48-week study and more frequently during VBRT (3/week) and 12 weeks of Aftercare (2/week).

Results

Extended VBRT produced longer durations of continuous cocaine abstinence during weeks 1–24 (5.7 vs 2.7 weeks; p = 0.003) and proportionally more abstinence during weeks 24–36 (X² = 4.57, p = .03, OR = 2.18) compared to Standard VBRT. Duration of VBRT did not directly predict after-VBRT abstinence; but longer continuous abstinence during VBRT predicted abstinence during Aftercare (p = 0.001) and during the last 12 weeks of the study (p < 0.001). Extended VBRT averaged higher monthly voucher costs compared to Standard VBRT ($96 vs $43, p < .001); however, the average cost per week of abstinence attained was higher in the Standard group ($8.06 vs $5.88, p < .001). Participants in the Extended group with voucher costs exceeding $25 monthly averaged 20 weeks of continuous abstinence.

Conclusions

Greater abstinence occurred during Extended VBRT, but providing a longer duration was not by itself sufficient to maintain abstinence after VBRT. However, if abstinence can be captured and sustained during VBRT, then providing longer durations may help increase the continuous abstinence that predicts better long-term outcomes.     

Public injecting and HIV risk behaviour among street-involved youth

Background

Although street-involved youth who inject illicit drugs are known to be at an increased risk of HIV and other adverse health outcomes, little is known about public injecting among this population and how injecting in public environments may impact HIV risk behaviour.

Methods

We used data derived from a study of 560 street-involved youth in Vancouver, Canada to examine the factors associated with injecting in public environments among youth who reported injecting drugs in the past 6 months.

Results

At baseline, 162 (28.9%) reported injecting drugs in the past 6 months. Among injectors, the 124 (76.5%) participants who reported injecting in public were more likely to be homeless (odds ratio [OR] = 6.39, p < 0.001), engage in unprotected intercourse (OR = 3.09, p = 0.004), deal drugs (OR = 2.26, p = 0.032), smoke crack cocaine (OR = 3.00, p = 0.005), inject heroin (OR = 3.48, p = 0.001), drop used syringes outdoors (OR = 8.44, p < 0.001), share syringes (OR = 4.43, p = 0.004), and were less likely to clean injection sites >75% of the time (OR = 0.36, p = 0.008). The majority (62.1%) reported feeling rushed while injecting in public.

Conclusions

Youth who inject in public are significantly more likely to engage in sexual and injection-related risk behaviour. Given the known elevated rates of HIV infection and other harms among this population, youth-focused interventions that target both sexual and drug-related risks associated with public drug-using environments are in urgent need of evaluation.     

Smoking prevalence,cigarette consumption and advice received from physicians: Change between 1996 and 2006 in Geneva,Switzerland

Objective

To assess change between 1996 and 2006 in smoking prevalence, cigarette consumption, quit attempts, motivation to quit and advice received from physicians in Geneva, Switzerland.

Methods

Postal surveys in cross-sectional, representative samples of the general population of Geneva in 1996 and 2006.

Results

There were 742 participants in 1996 (response rate 75%) and 1487 in 2006 (response rate 76%). Smoking prevalence remained stable between 1996 (28.0%, 95% confidence interval: 24.7 to 31.3%) and 2006 (26.5%, 24.3 to 28.7%, p = 0.46). Among smokers, cigarette consumption fell from 15 to 13 cig./day between 1996 and 2006 (p = 0.003). However, tobacco dependence, as measured by the Heaviness of Smoking Index, remained stable (mean = 1.9 vs. 1.7, p = 0.18). The proportion of smokers who made a 24-hour quit attempt in the previous year remained stable (29.2% in 1996, 32.1% in 2006, p = 0.52), but more smokers reported that they intended to quit in the next 6 months in 2006 (39.6%) than in 1996 (29.1%, p = 0.045). The association between smoking prevalence and income was stronger in 2006 (chi² = 53.7, p < 0.001) than in 1996 (chi² = 10.9, p = 0.012). In 2006 (no change since 1996), few smokers reported that, during their last medical visit, their physician told them to quit smoking (27.3%) or offered them help to quit (13.3%).

Conclusions

Over these 10 years, smoking prevalence, nicotine dependence levels and the frequency of quit attempts remained stable, but smokers' motivation to quit increased. We observed a growing social gap in smoking prevalence and cigarette consumption. Smoking cessation advice was seldom received during medical visits.     

Influence of reinforcer magnitude and nicotine amount on smoking's acute reinforcement enhancing effects

Background

Nicotine's acute effects on enhancing reinforcement from sensory rewards, shown in animal models, appear to occur with smoking in humans. These effects may vary due to reinforcer magnitude and amount of acute smoke intake (dose).

Methods

In a fully within-subjects design, dependent smokers (n = 23) participated in 3 sessions. Each session followed overnight abstinence and involved 4 trials to assess responding via progressive ratio (PR 50%) for sensory reinforcement from high, moderate, or low preference music, or no reward (counter-balanced, 30-s/reinforcer). Sessions differed in smoking prior to each trial: 8 puffs on arrival and 2 puffs/trial (“8 + 2″), 2 puffs/trial only (“0 + 2″), or no smoking. Puffs were consumed via CReSS (Clinical Research Support System) to control topography, and smoking involved own brand to ensure palatability and increase generalizability of results.

Results

Reinforced responding was influenced by main effects of smoking condition (p < .05) and music reward type (p < .001). Compared to no smoking, responding for music was increased after smoking 8 + 2/trial puffs (p < .005), but not after 0 + 2/trial puffs. Smoking condition significantly increased reinforced responding only for the high preference music (p = .01), and not for moderate or low preference music, or for no reward. Withdrawal did not differ between the two smoking sessions, ruling out withdrawal relief as an explanation for differential reinforcement enhancement.

Conclusions

Our findings confirm that just one cigarette after abstinence is sufficient for reinforcement enhancing effects and suggest that such enhancement is greater as magnitude of a reward's reinforcing efficacy increases.     

Family income trajectory during childhood is associated with adolescent cigarette smoking and alcohol use

Background

Although childhood socioeconomic disadvantage has been linked with adolescent tobacco and alcohol use in cross-sectional research, less is known about the influence of changes in socioeconomic status during childhood. Upward socioeconomic mobility may attenuate the negative influence of earlier socioeconomic disadvantage on health, while downward mobility may counter the health benefits of earlier socioeconomic advantage. This study evaluated the influence of common trajectories of family income during childhood on smoking and alcohol use during adolescence.

Methods

Data utilized were part of the 15-year longitudinal Study of Early Child Care and Youth Development. A 5-class trajectory model (two stable, one downward, and two upward income trajectories) was developed previously with this sample (N = 1356). Logistic regression analyses were conducted to determine whether children of the more disadvantaged income trajectories were more likely to engage in tobacco and alcohol use at age 15 relative to those of the most advantaged trajectory.

Results

Family income trajectory was significantly associated with ever-smoking (p = .02) and past-year alcohol use at age 15 years (p = .008). Children from the less advantaged trajectories were more likely to have ever-smoked than children of the most advantaged trajectory (all p's < .05). Children of the downwardly mobile trajectory were more likely to have used alcohol within the past year than children of the most advantaged trajectories as well as the most disadvantaged trajectory (all p's < .05).

Conclusions

Findings indicate that childhood socioeconomic disadvantage influences adolescent smoking, while downward socioeconomic mobility influences adolescent alcohol use.     

Does adenosine A1 receptor stimulation causes QRS prolongation by blocking beta adrenergic receptors in amitriptyline poisoning?

Aims

To investigate the role of beta receptor blockade via adenosine A₁ receptor stimulation on amitriptyline-induced QRS prolongation.

Methods

Isolated rat hearts were randomized into three groups (n = 8 for each group). After pretreatment with 5% dextrose (control) or DPCPX (8-cyclopentyl-1,3-dipropylxanthine), or propranolol + DPCPX, amitriptyline infusion was given to all groups. Intact beta adrenergic receptor response was verified with a bolus dose of isoproteranol (3 × 10⁻⁵ M).

Results

Amitriptyline (5.5 × 10⁻⁵ M) infusion following pretreatment with 5% dextrose or 10⁻⁴ M DPCPX prolonged QRS by 40–110% and 30–75%, respectively. After the beta receptor blockade with 10⁻² M propranolol bolus, amitriptyline infusion following pretreatment with DPCPX prolonged QRS by 40–130%. Amitriptyline infusion following pretreatment with DPCPX (10⁻⁴ M) shortened the QRS at 40, 50 and 60  min significantly when compared to propranolol + DPCPX group (168.8 ± 4.9%, p < 0.05; 170.8 ± 6.9%, p < 0.01; 174.0 ± 6.9%, p < 0.01, respectively). Amitriptyline infusion following pretreatment with 5% dextrose prolonged QRS duration significantly at 50th minutes (209.5 ± 6.1%, p < 0.05) compared to DPCPX pretreatment group.

Conclusion

DPCPX pretreatment shortened amitriptyline-induced QRS prolongation. Beta adrenergic receptor blockade enhanced QRS prolongation shortened by DPCPX pretreatment. Adenosine A₁ receptor stimulation related to beta adrenergic receptor blockade may play a role in amitriptyline-induced QRS prolongation in isolated rat hearts.     

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.