Atrial Fibrillation Due to Over The Counter Stimulant Drugs in A Young Adult

The usage of over the counter stimulant drugs and energy drinks is increasing on a day to day basis for various purposes including work, sports and leisure among individuals in all age groups. Multiple formulations are available in the market including pills, liquid capsules and drinks in various flavours. Many of them contain excessively high doses of caffeine along with a variety of stimulant compounds that have multiple effects in different parts of the human body. The consumption of such high amounts of caffeine itself has shown to have caused cardiac arrhythmias in healthy individuals and when it is mixed with a number of stimulant compounds can be associated with a number of adverse effects in the human body. However, the awareness of such life threatening complications associated with these energy drinks does not exist among people who consume it on a day to day basis. We report a case of 25-year-old Caucasian male with no significant past medical history for cardiac diseases, no risk factors for atrial fibrillation, non smoker, occasional alcohol drinker who presents with new onset atrial fibrillation with rapid ventricular response due to the consumption of over the counter stimulant energy capsule which had high doses of caffeine.

Atrial Fibrillation Due to Over The Counter Stimulant Drugs in A Young Adult

The usage of over the counter stimulant drugs and energy drinks is increasing on a day to day basis for various purposes including work, sports and leisure among individuals in all age groups. Multiple formulations are available in the market including pills, liquid capsules and drinks in various flavours. Many of them contain excessively high doses of caffeine along with a variety of stimulant compounds that have multiple effects in different parts of the human body. The consumption of such high amounts of caffeine itself has shown to have caused cardiac arrhythmias in healthy individuals and when it is mixed with a number of stimulant compounds can be associated with a number of adverse effects in the human body. However, the awareness of such life threatening complications associated with these energy drinks does not exist among people who consume it on a day to day basis. We report a case of 25-year-old Caucasian male with no significant past medical history for cardiac diseases, no risk factors for atrial fibrillation, non smoker, occasional alcohol drinker who presents with new onset atrial fibrillation with rapid ventricular response due to the consumption of over the counter stimulant energy capsule which had high doses of caffeine.

Commonly used stimulants: Sleep problems, dependence and psychological distress

BACKGROUND

Caffeine and nicotine are commonly used stimulants that enhance alertness and mood. Discontinuation of both stimulants is associated with withdrawal symptoms including sleep and mood disturbances, which may differ in males and females. The present study examines changes in sleep quality, daytime sleepiness and psychological distress associated with use and dependence on caffeine and nicotine.

METHODS

An online survey comprising validated tools to assess sleep quality, excessive daytime sleepiness and psychological distress was completed by 166 participants (74 males, 96 females) with a mean age of 28 years. Participants completed the study in their own time, and were not offered any inducements to participate.

RESULTS

Sleep quality was poorer in those dependent upon caffeine or nicotine, and there were also significant interaction effects with gender whereby females reported poorer sleep despite males reporting higher use of both stimulants. Caffeine dependence was associated with poorer sleep quality, increased daytime dysfunction, and increased levels of night time disturbance, while nicotine dependence was associated with poorer sleep quality and increased use of sleep medication and sleep disturbances. There were strong links between poor sleep and diminished affect, with psychological distress found to co-occur in the context of disturbed sleep.

CONCLUSIONS

Stimulants are widely used to promote vigilance and mood; however, dependence on commonly used drugs including caffeine and nicotine is associated with decrements in sleep quality and increased psychological distress, which may be compounded in female dependent users.

Amphetamine activates calcium channels through dopamine transporter-mediated depolarization

Amphetamine (AMPH) and its more potent enantiomer S(+)AMPH are psychostimulants used therapeutically to treat attention deficit hyperactivity disorder and have significant abuse liability. AMPH is a dopamine transporter (DAT) substrate that inhibits dopamine (DA) uptake and is implicated in DA release. Furthermore, AMPH activates ionic currents through DAT that modify cell excitability presumably by modulating voltage-gated channel activity. Indeed, several studies suggest that monoamine transporter-induced depolarization opens voltage-gated Ca(2+) channels (CaV), which would constitute an additional AMPH mechanism of action. In this study we co-express human DAT (hDAT) with Ca(2+) channels that have decreasing sensitivity to membrane depolarization (CaV1.3, CaV1.2 or CaV2.2). Although S(+)AMPH is more potent than DA in transport-competition assays and inward-current generation, at saturating concentrations both substrates indirectly activate voltage-gated L-type Ca(2+) channels (CaV1.3 and CaV1.2) but not the N-type Ca(2+) channel (CaV2.2). Furthermore, the potency to achieve hDAT-CaV electrical coupling is dominated by the substrate affinity on hDAT, with negligible influence of L-type channel voltage sensitivity. In contrast, the maximal coupling-strength (defined as Ca(2+) signal change per unit hDAT current) is influenced by CaV voltage sensitivity, which is greater in CaV1.3- than in CaV1.2-expressing cells. Moreover, relative to DA, S(+)AMPH showed greater coupling-strength at concentrations that induced relatively small hDAT-mediated currents. Therefore S(+)AMPH is not only more potent than DA at inducing hDAT-mediated L-type Ca(2+) channel currents but is a better depolarizing agent since it produces tighter electrical coupling between hDAT-mediated depolarization and L-type Ca(2+) channel activation.

Variations in parental monitoring and predictions of adolescent prescription opioid and stimulant misuse

OBJECTIVE

This study examined relations between adolescents' family structures, social ties, and drug-related attitudes, and their misuse of prescription opioids and stimulants. Different relationships were anticipated for the substances based on prior research highlighting varying motivations for their use.

METHOD

Based on an earlier model of adolescent substance misuse, two path analytic models were tested using data from 12 to 17 year olds in the 2012 U.S. National Survey on Drug Use and Health (NSDUH: N=17,399).

RESULTS

Female respondents reported higher levels of parental warmth, as did youth from wealthier families. Greater parental monitoring was reported by adolescents from wealthier and intact families. Parental monitoring and warmth predicted adolescents' social ties and individual differences associated with drug use, and both variables predicted prescription opioid and stimulant misuse. Contrary to previous research, for adolescents aged 12 to 14, high levels of parental monitoring, while positively associated with attitudes and social ties, also predicted higher rates of prescription stimulant misuse when combined with low levels of parental warmth. Results were cross-validated with data from the 2011 NSDUH.

CONCLUSIONS

Analyses highlighted the importance of understanding and differentiating the underlying factors associated with adolescent prescription stimulant and opioid misuse, and the role of parental behaviors in prevention.

The cognition-enhancing effects of psychostimulants involve direct action in the prefrontal cortex

Psychostimulants are highly effective in the treatment of attention-deficit/hyperactivity disorder. The clinical efficacy of these drugs is strongly linked to their ability to improve cognition dependent on the prefrontal cortex (PFC) and extended frontostriatal circuit. The procognitive actions of psychostimulants are only associated with low doses. Surprisingly, despite nearly 80 years of clinical use, the neurobiology of the procognitive actions of psychostimulants has only recently been systematically investigated. Findings from this research unambiguously demonstrate that the cognition-enhancing effects of psychostimulants involve the preferential elevation of catecholamines in the PFC and the subsequent activation of norepinephrine α2 and dopamine D1 receptors. In contrast, while the striatum is a critical participant in PFC-dependent cognition, where examined, psychostimulant action within the striatum is not sufficient to enhance cognition. At doses that moderately exceed the clinical range, psychostimulants appear to improve PFC-dependent attentional processes at the expense of other PFC-dependent processes (e.g., working memory, response inhibition). This differential modulation of PFC-dependent processes across dose appears to be associated with the differential involvement of noradrenergic α2 versus α1 receptors. Collectively, this evidence indicates that at low, clinically relevant doses, psychostimulants are devoid of the behavioral and neurochemical actions that define this class of drugs and instead act largely as cognitive enhancers (improving PFC-dependent function). This information has potentially important clinical implications as well as relevance for public health policy regarding the widespread clinical use of psychostimulants and for the development of novel pharmacologic treatments for attention-deficit/hyperactivity disorder and other conditions associated with PFC dysregulation.

Exercise outcomes in prevalent users of stimulant medications

BACKGROUND

To compare users of stimulant medications with matched nonusers on exercise outcomes during a maximal treadmill exercise test.

METHODS

A cross-sectional study of a community-based cohort comparing propensity-score-matched stimulant medication users (n = 245) and nonusers (n = 735) who underwent a maximal treadmill exercise test in the Cooper Center Longitudinal Study cohort from January 1, 1995 to December 31, 2013. Main Outcomes were peak systolic blood pressure (SBP), average rise in SBP, peak heart rate (HR), and estimated VO2max during exercise. A linear mixed model analysis was used to evaluate the effect of stimulant exposure on each of the exercise outcomes. In a sensitivity analysis, users were compared against nonusers for risk of chronotropic incompetence. Analyses were adjusted for relevant covariates and multiple testing.

RESULTS

Peak HR during exercise was significantly lower in stimulant medication users (least square mean estimate 170.2 beats/minute) compared to nonusers (174.4 beats/minute; p < 0.0001). Moreover, stimulant medication users had an increased risk of chronotropic incompetence compared to nonusers (adjusted odds ratio 3.28, 95% confidence interval 1.70 to 6.34, p = 0.0008). No significant differences were observed in the outcomes of peak SBP, average SBP rise, and estimated VO2max between matched groups.

CONCLUSIONS

Stimulant medication use was associated with a significant decrease in peak HR and an increased risk of chronotropic incompetence. Further investigation is required to understand the clinical significance of chronotropic incompetence in stimulant medication users. Concerns that stimulant medication use may increase peak SBP and average SBP during exercise were not supported by this study.

A population-based Swedish Twin and Sibling Study of cannabis, stimulant and sedative abuse in men

BACKGROUND

Prior studies, utilizing interview-based assessments, suggest that most of the genetic risk factors for drug abuse (DA) are non-specific with a minority acting specifically on risk for abuse of particular psychoactive substance classes. We seek to replicate these findings using objective national registry data.

METHODS

We examined abuse of cannabis, stimulants (including cocaine) and sedatives ascertained from national Swedish registers in male-male monozygotic (1720 pairs) and dizygotic twins (1219 pairs) combined with near-age full siblings (76,457 pairs) to provide sufficient power. Modeling was performed using Mx.

RESULTS

A common pathway model fitted better than an independent pathway model. The latent liability to DA was highly heritable but also influenced by shared environment. Cannabis, stimulant and sedative abuse all loaded strongly on the common factor. Estimates for the total heritability for the three forms of substance abuse ranged from 64 to 70%. Between 75 and 90% of that genetic risk was non-specific, coming from the common factor with the remainder deriving from substance specific genetic risk factors. By contrast, all of the shared environmental effects, which accounted for 18-20% of the variance in liability, were non-specific.

CONCLUSIONS

In accord with prior studies based on personal interviews, the large preponderance of genetic risk factors for abuse of specific classes of psychoactive substance are non-specific. These results suggest that genetic variation in the primary sites of action of the psychoactive drugs, which differ widely across most drug classes, play a minor role in human individual differences in risk for DA.

The Story of "Speed" from "Cloud Nine" to Brain Gain

The substituted amphetamines have had a checkered medical history intertwined with a sensational cultural history. Mankind's insatiable fascination with speed has led to widespread misuse sometimes with disastrous neurological and psychiatric consequences that may cause a permanent harm but their potential to enhance cognition should not be dismissed or forgotten. Further, smarter research could perhaps still lead to an expanded beneficial role for stimulant use in modern society.

Normative perceptions of non-medical stimulant use: associations with actual use and hazardous drinking

Approximately 10% of US college students are engaged in non-medical use of prescription stimulants (NMUPS) and that use is linked to concerning health, educational, and societal consequences. Few studies have assessed normative perceptions surrounding NMUPS. Accordingly, we examined self-reported use and normative perceptions for NMUPS and demographic factors that may be associated with them. We also investigated whether higher normative perceptions for NMUPS were related to the most commonly used and abused substance among college students (alcohol).

METHOD

1106 undergraduates participated in an online survey of normative perceptions of NMUPS and students' own drinking and stimulant use habits.

RESULTS

Students overestimated NMUPS by other students and those normative estimates were associated with higher NMUPS. Living in a fraternity or sorority was related to higher NMUPS and perceived norms. Finally, higher normative perceptions of NMUPS were associated with higher hazardous drinking.

CONCLUSION

The large discrepancy between actual use (generally low) and students' perceptions (generally high), and the relationship of these perceptions to both one's own use of NMUPS and alcohol suggests that interventions aimed at correcting norms may be useful.

Methamphetamine: an update on epidemiology, pharmacology, clinical phenomenology, and treatment literature

BACKGROUND

Despite initial reports of a decline in use in the early 2000s, methamphetamine remains a significant public health concern with known neurotoxic and neurocognitive effects to the user. The goal of this review is to update the literature on methamphetamine use and addiction since its assent to peak popularity in 1990s.

METHODS

We first review recent epidemiological reports with a focus on methamphetamine accessibility, changes in use and disorder prevalence rates over time, and accurate estimates of the associated burden of care to the individual and society. Second, we review methamphetamine pharmacology literature with emphasis on the structural and functional neurotoxic effects associated with repeated use of the drug. Third, we briefly outline the findings on methamphetamine-related neurocognitive deficits as assessed via behavioral and neuroimaging paradigms. Lastly, we review the clinical presentation of methamphetamine addiction and the evidence supporting the available psychosocial and pharmacological treatments within the context of an addiction biology framework.

CONCLUSION

Taken together, this review provides a broad-based update of the available literature covering methamphetamine research over the past two decades and concludes with recommendations for future research.

Do stimulant medications improve educational and behavioral outcomes for children with ADHD?

We examine the effects of a policy change in the province of Quebec, Canada which greatly expanded insurance coverage for prescription medications. We show that the change was associated with a sharp increase in the use of stimulant medications commonly prescribed for ADHD in Quebec relative to the rest of Canada. We ask whether this increase in medication use was associated with improvements in emotional functioning or academic outcomes among children with ADHD. We find little evidence of improvement in either the medium or the long run. Our results are silent on the effects on optimal use of medication for ADHD, but suggest that expanding medication in a community setting had little positive benefit and may have had harmful effects given the average way these drugs are used in the community.

The impact of engagement in street-based income generation activities on stimulant drug use cessation among people who inject drugs

BACKGROUND

Despite the growing prevalence of illicit stimulant drug use internationally, and the widespread involvement of people who inject drugs (IDU) within street-based drug markets, little is known about the impact of different types of street-based income generation activities on the cessation of stimulant use among IDU.

METHODS

Data were derived from an open prospective cohort of IDU in Vancouver, Canada. We used Kaplan-Meier methods and Cox proportional hazards regression to examine the effect of different types of street-based income generation activities (e.g., sex work, drug dealing, and scavenging) on time to cessation of stimulant use.

RESULTS

Between December, 2005 and November, 2012, 887 IDU who use stimulant drugs (cocaine, crack cocaine, or crystal methamphetamine) were prospectively followed-up for a median duration of 47 months. In Kaplan-Meier analyses, compared to those who did not engage in street-based income generation activities, participants who reported sex work, drug dealing, scavenging, or more than one of these activities were significantly less likely to report stimulant drug use cessation (all p<0.001). When considered as time-updated variables and adjusted for potential confounders in a multivariable model, each type of street-based income generation activity remained significantly associated with a slower time to stimulant drug cessation (all p<0.005).

CONCLUSIONS

Our findings highlight the urgent need for strategies to address stimulant dependence, including novel pharmacotherapies. Also important, structural interventions, such as low-threshold employment opportunities, availability of supportive housing, legal reforms regarding drug use, and evidence-based approaches that reduce harm among IDU are urgently required.

New perspectives on using brain imaging to study CNS stimulants

While the recent application of brain imaging to study CNS stimulants has offered new insights into the fundamental factors that contribute to their use and abuse, many gaps remain. Brain circuits that mediate pleasure, dependence, craving and relapse are anatomically, neurophysiologically and neurochemically distinct from one another, which has guided the search for correlates of stimulant-seeking and taking behavior. However, unlike other drugs of abuse, metrics for tolerance and physical dependence on stimulants are not obvious. The dopamine theory of stimulant abuse does not sufficiently explain this disorder as serotonergic, GABAergic and glutamagergic circuits are clearly involved in stimulant pharmacology and so tracking the source of the "addictive" processes must adopt a more multimodal, multidisciplinary approach. To this end, both anatomical and functional magnetic resonance imaging (MRI), MR spectroscopy (MRS) and positron emission tomography (PET) are complementary and have equally contributed to our understanding of how stimulants affect the brain and behavior. New vistas in this area include nanotechnology approaches to deliver small molecules to receptors and use MRI to resolve receptor dynamics. Anatomical and blood flow imaging has yielded data showing that cognitive enhancers might be useful adjuncts in treating CNS stimulant dependence, while MRS has opened opportunities to examine the brain's readiness to accept treatment as GABA tone normalizes after detoxification. A desired outcome of the above approaches is being able to offer evidence-based rationales for treatment approaches that can be implemented in a more broad geographic area, where access to brain imaging facilities may be limited. This article is part of the Special Issue entitled 'CNS Stimulants'.

Methylphenidate and brain activity in a reward/conflict paradigm: role of the insula in task performance

Psychostimulants, such as methylphenidate, are thought to improve information processing in motivation-reward and attention-activation networks by enhancing the effects of more relevant signals and suppressing those of less relevant ones; however the nature of such reciprocal influences remains poorly understood. To explore this question, we tested the effect of methylphenidate on performance and associated brain activity in the Anticipation, Conflict, Reward (ACR) task. Sixteen healthy adult volunteers, ages 21-45, were scanned twice using functional magnetic resonance imaging (fMRI) as they performed the ACR task under placebo and methylphenidate conditions. A three-way repeated measures analysis of variance, with cue (reward vs. non-reward), target (congruent vs. incongruent) and medication condition (methylphenidate vs. placebo) as the factors, was used to analyze behaviors on the task. Blood oxygen level dependent (BOLD) signals, reflecting task-related neural activity, were evaluated using linear contrasts. Participants exhibited significantly greater accuracy in the methylphenidate condition than the placebo condition. Compared with placebo, the methylphenidate condition also was associated with lesser task-related activity in components of attention-activation systems irrespective of the reward cue, and less task-related activity in components of the reward-motivation system, particularly the insula, during reward trials irrespective of target difficulty. These results suggest that methylphenidate enhances task performance by improving efficiency of information processing in both reward-motivation and in attention-activation systems.

Cardiovascular stimulant actions of bupropion in comparison to cocaine in the rat

Stimulants are banned in competition by the World Anti-Doping Agency, except for a small number of therapeutic agents subject to monitoring, including bupropion. We have examined the potency of bupropion in comparison with two agents banned in competition, adrafinil and modafinil, and with cocaine and desipramine as blockers of the noradrenaline re-uptake transporter in peripheral tissues of the rat. For studies in vivo, the pressor response to noradrenaline in the anaesthetized rat was studied. Cocaine, desipramine and bupropion at doses of 0.1, 0.3 and 1mg/kg, respectively, significantly increased the pressor response to noradrenaline. Overall, cocaine and desipramine were approximately 2-5 times more potent than bupropion in vivo in the rat. Adrafinil and modafinil (both 3mg/kg) did not significantly affect the pressor response. Bupropion was chosen for further study. In 1Hz paced rat right ventricular strips, bupropion (30μM) significantly increased the potency of noradrenaline at increasing the force of contraction. In rat vas deferens, bupropion and cocaine produced concentration-dependent increases in the contractile response to nerve stimulation, and cocaine was 11 times more potent than bupropion. Since bupropion is used clinically in doses of up to 300mg, it is likely that bupropion has actions at the noradrenaline transporter, and thus cardiovascular stimulant actions, in clinical doses. This may explain findings of increased exercise performance with bupropion.

Pharmaco-MEG evidence for attention related hyper-connectivity between auditory and prefrontal cortices in ADHD

The ability to attend to particular stimuli while ignoring others is crucial in goal-directed activities and has been linked with prefrontal cortical regions, including the dorsolateral prefrontal cortex (DLPFC). Both hyper- and hypo-activation in the DLPFC has been reported in patients with attention-deficit/hyperactivity disorder (ADHD) during many different cognitive tasks, but the network-level effects of such aberrant activity remain largely unknown. Using magnetoencephalography (MEG), we examined functional connectivity between regions of the DLPFC and the modality-specific auditory cortices during an auditory attention task in medicated and un-medicated adults with ADHD, and those without ADHD. Participants completed an attention task in two separate sessions (medicated/un-medicated), and each session consisted of two blocks (attend and no-attend). All MEG data were coregistered to structural MRI, corrected for head motion, and projected into source space. Subsequently, we computed the phase coherence (i.e., functional connectivity) between DLPFC regions and the auditory cortices. We found that un-medicated adults with ADHD exhibited greater phase coherence in the beta (14-30Hz) and gamma frequency (30-56Hz) range in attend and no-attend conditions compared to controls. Stimulant medication attenuated these differences, but did not fully eliminate them. These results suggest that aberrant bottom-up processing may engulf executive resources in ADHD.

Energy drink consumption among young Australian adults: associations with alcohol and illicit drug use

BACKGROUND

Energy drinks are becoming increasingly popular among young people. The purpose of this study was to determine the prevalence of energy drink consumption and its associations with socio-demographic characteristics, alcohol, cigarette and illicit drug use in a population-based sample of young adults participating in the Western Australian Pregnancy Cohort (Raine) Study.

METHODS

We used self-administered questionnaires to assess energy drink consumption patterns, alcohol intake, cigarette and illicit drug use at the 20-year cohort follow-up. Data was also collected on socio-demographics, physical activity, body mass index (BMI) and dietary intake. Our sample included 1234 participants (47% male, mean age 20 ± 0.5 years). We considered energy-drink consumption as a categorical (users versus non-users) variable.

RESULTS

Overall, 48% of participants consumed energy drinks at least once per month, with an average intake of 1.31 ± 0.75 cans per day amongst energy drink users. The most significant correlates of energy drink use were being in part-time or full-time employment, being male, being a cigarette smoker, having heavier alcoholic spirit consumption patterns and being an ecstasy user (all p<0.05). No significant associations were observed with BMI or dietary intake.

CONCLUSIONS

Australian energy drink users tend to have heavier alcohol consumption patterns be a cigarette smoker and use illicit drugs relative to non-users. More research is needed regarding the health risks associated with energy drink use in young adults, including their possible role in the development of substance abuse problems.

Cognitive enhancement in children and adolescents: is it in their best interests?

Evidence suggests children and adolescents are consuming stimulants and nonstimulants in the hopes of improving academic performance through cognitive enhancement. As such, clinicians may be faced with requests to prescribe enhancers for their paediatric patients. In this article, we analyse the ethics of cognitive enhancement in paediatrics in the light of the best interests standard, a guiding principle, often used to make decisions for minors in moral, legal, social and medical contexts.

CONCLUSION

Cognitive enhancement in children and adolescents does not represent an ethical ideal that societies should strive for. Furthermore, paediatric cognitive enhancement does not meet the criteria for a minimally acceptable practice, given the health-related risks posed by these medications and the coercive environments such a practice creates. In line with a recent policy statement by the American Academy of Neurology, ethical and clinical arguments based on the best interests of paediatric patients encourage clinicians to refrain from engaging in this practice.

Methylphenidate remediates error-preceding activation of the default mode brain regions in cocaine-addicted individuals

Many previous studies suggest the potential of psychostimulants in improving cognitive functioning. Our earlier pharmacological brain imaging study showed that intravenous methylphenidate (MPH) improves inhibitory control by altering cortico-striato-thalamic activations in cocaine-dependent (CD) individuals. Here we provide additional evidence for the effects of MPH in restoring cerebral activations during cognitive performance. Ten CD individuals performed a stop signal task (SST) during functional magnetic resonance imaging (fMRI) in two sessions, in which either MPH (0.5mg/kg body weight) or saline was administered intravenously. In the SST, a frequent go signal instructs participants to make a speeded response and a less frequent stop signal instructs them to withhold the response. Our previous work described increased activation of the precuneus/posterior cingulate cortex and ventromedial prefrontal cortex-regions of the default mode network (DMN)-before participants committed a stop error in healthy control but not CD individuals (Bednarski et al., 2011). The current results showed that, compared to saline, MPH restored error-preceding activations of DMN regions in CD individuals. The extent of the changes in precuneus activity was correlated with MPH-elicited increase in systolic blood pressure. These findings suggest that the influence of MPH on cerebral activations may extend beyond cognitive control and provide additional evidence warranting future studies to investigate the neural mechanisms and physiological markers of the efficacy of agonist therapy in cocaine dependence.

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.

Preliminary findings: Contingency management targeting psycho-stimulant use results in secondary decreases in smoking for severely mentally ill adults

BACKGROUND

Treatments for drug addiction and smoking in severely mentally ill (SMI) adults are needed.

OBJECTIVES

To investigate the effect of a contingency management (CM) intervention targeting psycho-stimulant on cigarette smoking.

METHODS

126 stimulant dependent SMI smokers were assigned to CM or a non-contingent control condition. Rates of smoking-negative (<3 ppm) carbon monoxide breath-samples were compared.

RESULTS

Individuals who received CM targeting psycho-stimulants were 79% more likely to submit a smoking-negative breath-sample relative to controls.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

This study provides initial evidence that a behavioral treatment for drug use results in reductions in cigarette smoking in SMI adults.

Bath salts and synthetic cathinones: an emerging designer drug phenomenon

Synthetic cathinones are an emerging class of designer drugs abused for psychostimulant and hallucinogenic effects similar to cocaine, methylenedioxymethamphetamine (MDMA), or other amphetamines. Abuse of synthetic cathinones, frequently included in products sold as 'bath salts', became prevalent in early 2009, leading to legislative classification throughout Europe in 2010 and schedule I classification within the United States in 2011. Recent pre-clinical and clinical studies indicate that dysregulation of central monoamine systems is a principal mechanism of synthetic cathinone action and presumably underlie the behavioral effects and abuse liability associated with these drugs. This review provides insight into the development of synthetic cathinones as substances of abuse, current patterns of their abuse, known mechanisms of their action and toxicology, and the benefits and drawbacks of their classification.

Sociodemographic and substance use characteristics of γ hydroxybutyrate (GHB) dependent inpatients and associations with dependence severity

BACKGROUND

The number of admissions to addiction treatment centers in the Netherlands for gamma hydroxybutyrate (GHB) dependence is rapidly growing. Until now, treatment seeking GHB users have hardly been studied. This study characterizes inpatients in treatment for GHB dependence in terms of sociodemographics, motives for substance use and reasons for seeking treatment. In addition, variables associated with dependence severity are identified.

METHODS

Patients were recruited by their therapists at 4 different addiction treatment centers dispersed throughout the Netherlands. They were asked to fill out the questionnaire, including sociodemographic and clinical characteristics, GHB and other drug use, and a modified version of the Drug Use Disorders Identification Test (DUDIT) to screen for GHB dependence. The associations of relevant variables with dependence severity were determined using multiple regression analysis.

RESULTS

A total of 75 inpatients (response rate 90.4%) participated in the study. Most patients were young (mean 26.8 ± 9.1) males (73%) with low education (78%) and not employed (48%). Most of them (75%) had started using GHB the year before treatment admission, 42 (56%) frequently combined GHB with sedatives and 26 (35%) frequently combined GHB with stimulants. Dependence severity was strongly associated with sleep problems and the combined use of GHB and stimulants.

CONCLUSION

This study shows that sociodemographic characteristics of GHB inpatients are similar to those of problematic users of other club drugs. Sleep problems and combined use of GHB and stimulants were strongly associated with GHB dependence. Together, these factors might help to better identify people at risk for GHB dependence.

A proposal for refining the forced swim test in Swiss mice

The forced swim test (FST) is a preclinical test to the screening of antidepressants based on rats or mice behaviours, which is also sensitive to stimulants of motor activity. This work standardised and validated a method to register the active and passive behaviours of Swiss mice during the FST in order to strength the specificity of the test. Adult male Swiss mice were subjected to the FST for 6 min without any treatment or after intraperitoneal injection of saline (0.1 ml/10 g), antidepressants (imipramine, desipramine, or fluoxetine, 30 mg/kg) or stimulants (caffeine, 30 mg/kg or apomorphine, 10mg/kg). The latency, frequency and duration of behaviours (immobility, swimming, and climbing) were scored and summarised in bins of 6, 4, 2 or 1 min. Parameters were first analysed using Principal Components Analysis generating components putatively related to antidepressant (first and second) or to stimulant effects (third). Antidepressants and stimulants affected similarly the parameters grouped into all components. Effects of stimulants on climbing were better distinguished of antidepressants when analysed during the last 4 min of the FST. Surprisingly, the effects of antidepressants on immobility were better distinguished from saline when parameters were scored in the first 2 min. The method proposed here is able to distinguish antidepressants from stimulants of motor activity using Swiss mice in the FST. This refinement should reduce the number of mice used in preclinical evaluation of antidepressants.

National trends in pharmaceutical opioid related overdose deaths compared to other substance related overdose deaths: 1999-2009

BACKGROUND

Pharmaceutical opioid related deaths have increased. This study aimed to place pharmaceutical opioid overdose deaths within the context of heroin, cocaine, psychostimulants, and pharmaceutical sedative hypnotics examine demographic trends, and describe common combinations of substances involved in opioid related deaths.

METHODS

We reviewed deaths among 15-64 year olds in the US from 1999-2009 using death certificate data available through the CDC Wide-Ranging Online Data for Epidemiologic Research (WONDER) Database. We identified International Classification of Disease-10 codes describing accidental overdose deaths, including poisonings related to stimulants, pharmaceutical drugs, and heroin. We used crude and age adjusted death rates (deaths/100,000 person years [p-y] and 95% confidence interval [CI] and multivariable Poisson regression models, yielding incident rate ratios; IRRs), for analysis.

RESULTS

The age adjusted death rate related to pharmaceutical opioids increased almost 4-fold from 1999 to 2009 (1.54/100,000 p-y [95% CI 1.49-1.60] to 6.05/100,000 p-y [95% CI 5.95-6.16; p<0.001). From 1999 to 2009, pharmaceutical opioids were responsible for the highest relative increase in overdose death rates (IRR 4.22, 95% CI 3.03-5.87) followed by sedative hypnotics (IRR 3.53, 95% CI 2.11-5.90). Heroin related overdose death rates increased from 2007 to 2009 (1.05/100,000 persons [95% CI 1.00-1.09] to 1.43/100,000 persons [95% CI 1.38-1.48; p<0.001). From 2005-2009 the combination of pharmaceutical opioids and benzodiazepines was the most common cause of polysubstance overdose deaths (1.27/100,000 p-y (95% CI 1.25-1.30).

CONCLUSION

Strategies, such as wider implementation of naloxone, expanded access to treatment, and development of new interventions are needed to curb the pharmaceutical opioid overdose epidemic.

Characterizing the cognitive effects of cocaine: a comprehensive review

Understanding the cognitive sequela of repeated cocaine use is a growing area of research and is crucial to the development of cognitive models of addiction. We systematically reviewed all available placebo-controlled and case-controlled studies on the acute and long-term effects of cocaine on cognitive functioning. In order to compare the magnitude of cognitive effects across cognitive domains we conducted several meta-analyses on a subset of data from long-term effect studies. Studies on acute cocaine administration suggest enhancement of response inhibition and psychomotor speed, while all other domains appear to be unaffected or not investigated adequately. Long-term effects of cocaine show a wide array of deteriorated cognitive functions, indicating that long term cocaine use is characterized by a general cognitive impairment across functions, rather than by specific cognitive deficits. Literature on long-term cocaine effects is more substantial than literature on acute effects. This comprehensive review outlines possible dissociations and similarities of acute vs. long-term cocaine effects in the human brain. Atherosclerosis after cocaine exposure may underlie cognitive dysfunction, suggesting involvement of multiple brain areas. Acute drug studies are important to the future development of addiction models.

Application of LC-MS/MS for quantitative analysis of glucocorticoids and stimulants in biological fluids

Liquid chromatography tandem mass chromatography (LC-MS/MS) is an important hyphenated technique for quantitative analysis of drugs in biological fluids. Because of high sensitivity and selectivity, LC-MS/MS has been used for pharmacokinetic studies, metabolites identification in the plasma and urine. This manuscript gives comprehensive analytical review, focusing on chromatographic separation approaches (column packing materials, column length and mobile phase) as well as different acquisition modes (SIM, MRM) for quantitative analysis of glucocorticoids and stimulants. This review is not meant to be exhaustive but rather to provide a general overview for detection and confirmation of target drugs using LC-MS/MS and thus useful in the doping analysis, toxicological studies as well as in pharmaceutical analysis.

Psychostimulants and motivated behavior: arousal and cognition

Motivated, goal-directed behavior requires the coordination of multiple behavioral processes that facilitate interacting with the environment, including arousal, motivation, and executive function. Psychostimulants exert potent modulatory influences on these processes, providing a useful tool for understanding the neurobiology of motivated behavior. The neural mechanisms underlying the reinforcing effects of psychostimulants have been extensively studied over the past 50 years. In contrast, the study of the neurobiology of the arousal-enhancing and executive-modulating actions of psychostimulants was only initiated relatively recently. This latter work identifies a series of dose-dependent actions of psychostimulants within a network of prefrontal cortical and subcortical sites that coordinate the arousal-promoting and cognition-modulating effects of these drugs. These actions are dependent on a variety of catecholamine receptor subtypes, including noradrenergic α1 and α2 receptors and dopaminergic D1 receptors. In the prefrontal cortex, psychostimulants exert inverted-U shaped modulatory actions that are apparent at the levels of the neuron and behavior. Collectively, these observations provide new insight into the neurobiology underlying motivated, goal-directed behavior.

Drug therapy of attention deficit hyperactivity disorder: current trends

Attention deficit hyperactivity disorder is a developmental disorder with an age onset prior to 7 years. Children with ADHD have significantly lower ability to focus and sustain attention and also score higher on impulsivity and hyperactivity. Stimulants, such as methylphenidate, have remained the mainstay of ADHD treatment for decades with evidence supporting their use. However, recent years have seen emergence of newer drugs and drug delivery systems, like osmotic release oral systems and transdermal patches, to mention a few. The use of nonstimulant drugs like atomoxetine and various other drugs, such as α-agonists, and a few antidepressants, being used in an off-label manner, have added to the pharmacotherapy of ADHD. This review discusses current trends in drug therapy of ADHD and highlights the promise pharmacogenomics may hold in the future.

Use of stimulant substances among university students in tehran: a qualitative study

OBJECTIVE

There is evidence to show an increase in use of stimulant substances among university students. This study is a qualitative assessment of the existing situation and the underlying reasons for stimulant use among the students of Tehran University of Medical Sciences in 2006.

METHODS

Three qualitative methods have been used: focus group discussions with 7 groups (60 individuals) consisting of male and female students in the dormitories and in the university environment, in-depth interview with 20 drug user students, and interview with 20 key informants including counselors, managers and guards of dormitories, staff of the office for Culture and Welfare Affairs of students and members of students' organizations. Purposeful or opportunistic method was used for sampling.

RESULTS

Ecstasy and methylphenidate (Ritalin) were mentioned as the stimulants used by the students. The main declared reasons for ecstasy use were desire to have fun and excitement, desire to modernity, participation in parties, curiosity and living without family. The high expense of ecstasy pills and the training provided by media were mentioned as the main protective factors. Most respondents believed that use of methylphenidate was more prevalent than ecstasy use. In contrary to the drugs used for fun and enjoyment, methylphenidate is used for increasing learning abilities and academic achievement. Other pointed- out factors were ease of use and being stigma-free. Conclusion Increasing risk perception via training, social alternatives to risky activities and parental training for continuing care and advice in the college period are recommended.

The Dopamine Dilemma-Part II: Could Stimulants Cause Tolerance, Dependence, and Paradoxical Decompensation?

In this commentary, the author calls to attention that stimulants are commonly prescribed to children for years without seeming regard to the lack of studies on efficacy and safety during long-term use. The author examines evidence for stimulants losing efficacy over time and provides multiple possible mechanisms. The potential for paradoxical decompensation, an iatrogenic worsening of symptoms over time, is considered and discussed. Recommendations for detecting and responding to possible stimulant tolerance and dependence are provided.

Young People's Experience of ADHD and Stimulant Medication: A Qualitative Study for the NICE Guideline

BACKGROUND

  The NICE ADHD Guideline Group found a lack of research evidence on young people's experiences with stimulant medications. The present study was commissioned to help fill this gap in the evidence base and to inform the Guideline.

METHOD

  Focus groups and 1:1 interviews with 16 UK young people with ADHD.

RESULTS

  Young people were positive about taking medication, feeling that it reduced their disruptive behaviour and improved their peer relationships. Young people experienced stigma but this was related more to their symptomatic behaviours than to stimulant drug medication.

CONCLUSIONS

  The study's findings helped to inform the NICE guideline on ADHD by providing evidence that young people's experiences of medication were in general more positive than negative. All NICE Guidelines involving recommendations for the treatment of young people should draw on research evidence of young people's experiences of treatments.