Differential effects of cocaine and cocaine alcohol on neurocognitive performance

Residual deficits in functional brain activity after chronic cocaine self-administration in rhesus monkeys

Previous studies in humans and in animals have shown dramatic effects of cocaine on measures of brain function that persist into abstinence. The purpose of this study was to examine the neurobiological consequences of abstinence from cocaine, using a model that removes the potential confound of cocaine cues. Adult male rhesus monkeys self-administered cocaine (0.3 mg/kg/injection; N = 8) during daily sessions or served as food-reinforcement controls (N = 4). Two times per week, monkeys were placed in a neutral environment and presented with a cartoon video for ~30 min, sometimes pre- and sometimes post-operant session, but no reinforcement was presented during the video. After ~100 sessions and when the cocaine groups had self-administered 900 mg/kg cocaine, the final experimental condition was a terminal 2-[14C]-deoxyglucose procedure, which occurred in the neutral (cartoon video) environment; for half of the monkeys in each group, this occurred after 1 day of abstinence and for the others after 30 days of abstinence. Rates of local cerebral glucose metabolism were measured in 57 brain regions. Global rates of cerebral metabolism were significantly lower in animals 1 day and 30 days post-cocaine self-administration when compared to those of food-reinforced controls. Effects were larger in 30- vs. 1-day cocaine abstinence, especially in prefrontal, parietal and cingulate cortex, as well as dorsal striatum and thalamus. Because these measures were obtained from monkeys while in a neutral environment, the deficits in glucose utilization can be attributed to the consequences of cocaine exposure and not to effects of conditioned stimuli associated with cocaine.

Patterns of Prescription Medicine, Illicit Drugs, and Alcohol Misuse among High-Risk Population: A Factor Analysis to Delineate Profiles of Polydrug Users

Polydrug use is a serious health and social problem worldwide. Treatment remains a challenge because it requires planning based on estimates of the nature and extent of drug consumption and the characteristics of the population in need. To this end, 103 subjects, who voluntarily asked to begin rehabilitation treatment, were monitored through hair analysis to investigate the nature and extent of their polydrug use. A factor analysis was carried out to delineate polydrug user profiles based on the following variables: age, sex, type of illicit drug use, type of prescription drug misuse, and amount of alcohol consumption. Twenty-three percent of subjects tested positive to more than one illicit drug (mainly cocaine), 44% to unprescribed drugs (mainly benzodiazepines), and 66% were hard drinkers. The profiles of drug users outlined included “single drug cocaine user”, and “single drug opiate user”. Moreover, a particularly problematic profile of cocaine users, common between genders and age groups, who combine high levels of alcohol and unprescribed benzodiazepines and opiates, emerged (“hard polydrug abusers”). From a treatment policy perspective, these findings support the importance of preventive analysis before rehabilitation treatment begins in order to identify different patterns of drug abusers to implement personalized multidisciplinary measures.

Bidirectional causality between addiction and cognitive deficits

Cognitive deficits are highly comorbid with substance use disorders. Deficits span multiple cognitive domains, are associated with disease severity across substance classes, and persist long after cessation of substance use. Furthermore, recovery of cognitive function during protracted abstinence is highly predictive of treatment adherence, relapse, and overall substance use disorder prognosis, suggesting that addiction may be best characterized as a disease of executive dysfunction. While the association between cognitive deficits and substance use disorders is clear, determining causalities is made difficult by the complex interplay between these variables. Cognitive dysfunction present prior to first drug use can act as a risk factor for substance use initiation, likelihood of pathology, and disease trajectory. At the same time, substance use can directly cause cognitive impairments even in individuals without preexisting deficits. Thus, parsing preexisting risk factors from substance-induced adaptations, and how they may interact, poses significant challenges. Here, focusing on psychostimulants and alcohol, we review evidence from clinical literature implicating cognitive deficits as a risk factor for addiction, a consequence of substance use, and the role the prefrontal cortex plays in these phenomena. We then review corresponding preclinical literature, highlighting the high degree of congruency between animal and human studies, and emphasize the unique opportunity that animal models provide to test causality between cognitive phenotypes and substance use, and to investigate the underlying neurobiology at a cellular and molecular level. Together, we provide an accessible resource for assessing the validity and utility of forward- and reverse-translation between these clinical and preclinical literatures.

Salivary Cortisol Levels Are Associated with Craving and Cognitive Performance in Cocaine-Abstinent Subjects: A Pilot Study

Cortisol is a glucocorticoid hormone secreted by the adrenal cortex upon the activation of the hypothalamic-pituitary-adrenal (HPA) axis. Assessment of cortisol in saliva has emerged as a reliable way of evaluating HPA function. We examined the relationships between salivary cortisol levels with both craving and cognitive performance, as a possible biomarker of cocaine addiction. Cognitive performance (attention, declarative and working memory, executive functions and recognition of emotions) was assessed in 14 abstinent cocaine-dependent subjects in outpatient treatment and 13 control participants. Three salivary samples were collected at home by all the participants in the morning, afternoon and at bedtime. Patients showed higher levels of cortisol in the morning, as well as higher area under the curve with respect to the ground (AUCg). Regarding cognitive performance, cocaine-abstinent subjects showed worse performance in attention (d2 test), verbal memory (Spanish Complementary Verbal Learning Test, TAVEC) and executive tests (Tower of Hanoi and phonological fluency test) with respect to the control group. Morning cortisol levels and the AUCg index were negatively associated with the age of onset of drug consumption and the AUCg index was also positively associated with craving in our patients' group. Moreover, morning cortisol levels, as well as the AUCg index, were negatively associated with verbal memory performance. Therefore, our pilot study suggests that salivary cortisol measurements could be a good avenue to predict craving level, as well as cognitive status, especially the declarative memory domain.

Cognitive reserve mediates the severity of certain neuropsychological deficits related to cocaine use disorder

The concept of cognitive reserve (CR) is being considered in the field of substance use disorder (SUD) by observing that there are individuals whose brain alterations are not related to the cognitive symptomatology they present. Our aims were to characterise the possible neuropsychological deficits in a sample of subjects with SUD compared to healthy controls and to determine whether the degree of CR is a mediator in the cognitive functioning of these patients. To perform these objectives, the study involved a sample of subjects with SUD in outpatient treatment and a healthy control group. A CR questionnaire and a comprehensive neuropsychological assessment were administered, and we also collected data related to drug consumption and psychological well-being. The SUD group showed poorer performance compared to the control group in several cognitive domains (attention, declarative memory, executive functions and emotional perception), as well as in psychological comfort. Interestingly, we observed that the deficits found in attention and processing speed were highly mediated by the CR level of the participants, an effect that we did not observe in the rest of the variables registered. Our results suggest that long-term drug consumption leads to cognitive deficits and affects the psychological well-being of the subjects. Moreover, the CR should be taken into account during the assessment and rehabilitation of patients with SUD due to its protective role against certain neuropsychological deficits.

Adolescent-onset vs. adult-onset cocaine use: Impact on cognitive functioning in animal models and opportunities for translation

Animal models are poised to make key contributions to the study of cognitive deficits associated with chronic cocaine use in people. Advantages of animal models include use of a longitudinal experimental design that can control for drug use history and onset-age, sex, drug consumption, and abstinence duration. Twenty-two studies were reviewed (13 in adult male rats, 5 in adolescent vs. adult male rats, 3 in adult male monkeys, and 1 in adult female monkeys), and it was demonstrated repeatedly that male animals with adult-onset cocaine self-administration exposure had impairments in sustained attention, decision making, stimulus-reward learning, working memory, and cognitive flexibility, but not habit learning and spatial learning and memory. These findings have translational relevance because adult cocaine users exhibit a similar range of cognitive deficits. In the limited number of studies available, male rats self-administering cocaine during adolescence were less susceptible than adults to impairment in cognitive flexibility, stimulus-reward learning, and decision making, but were more susceptible than adults to impairment in working memory, a finding also reported in the few studies performed in early-onset cocaine users. These findings suggest that animal models can help fill an unmet need for investigating important but yet-to-be-fully-addressed research questions in people. Research priorities include further investigation of differences between adolescents and adults as well as between males and females following chronic cocaine self-administration. A comprehensive understanding of the broad range of cognitive consequences of chronic cocaine use and the role of developmental plasticity can be of value for improving neuropsychological recovery efforts.

Eustress and Distress: Neither Good Nor Bad, but Rather the Same?

The terms "eustress" and "distress" are widely used throughout the scientific literature. As of February 2020, 203 items in the Web of Science show up in a search for "eustress," however, there are almost 16 400 items found in a search for the term "distress." Based on the reasoning in this article, however, it is believed there is no such thing as eustress or distress. The adaptation reaction of an organism under stress is not intrinsically good or bad, and its effect on health or performance depends on a plethora of other interactions of the body with the environment as well as on the history of such interactions. The vagueness of the terms "eustress/distress" has historically led to vast differences in the perception and application of the terms across disciplines. While psychology or sociology perceive eustress as something inextricably linked to positive perception and enhanced cognition, biomedicine perceives eustress as generally associated with better survival, health, or increased longevity, no matter how the event is perceived. In this paper, the authors review the current understanding of the term "eustress" in different fields, discuss possible implications of its misleading use, and suggest that the term may be replaced by "stress" only.

Conditional Effects of Lifetime Alcohol Consumption on Methamphetamine-Associated Neurocognitive Performance

OBJECTIVES

Methamphetamine (MA) dependence contributes to neurotoxicity and neurocognitive deficits. Although combined alcohol and MA misuse is common, how alcohol consumption relates to neurocognitive performance among MA users remains unclear. We hypothesized that alcohol and MA use would synergistically diminish neurocognitive functioning, such that greater reported alcohol consumption would exert larger negative effects on neurocognition among MA-dependent individuals compared to MA-nonusing persons.

METHODS

Eighty-seven MA-dependent (MA+) and 114 MA-nonusing (MA-) adults underwent neuropsychological and substance use assessments. Linear and logistic regressions examined the interaction between MA status and lifetime average drinks per drinking day on demographically corrected global neurocognitive T scores and impairment rates, controlling for recent alcohol use, lifetime cannabis use, WRAT reading performance, and lifetime depression.

RESULTS

MA+ displayed moderately higher rates of impairment and lower T scores compared to MA-. Lifetime alcohol use significantly interacted with MA status to predict global impairment (ORR = 0.70, p = .003) such that greater lifetime alcohol use increased likelihood of impairment in MA-, but decreased likelihood of impairment in MA+. Greater lifetime alcohol use predicted poorer global T scores among MA- (b = -0.44, p = .030) but not MA+ (b = 0.08, p = .586).

CONCLUSIONS

Contrary to expectations, greater lifetime alcohol use related to reduced risk of neurocognitive impairment among MA users. Findings are supported by prior research identifying neurobiological mechanisms by which alcohol may attenuate stimulant-driven vasoconstriction and brain thermotoxicity. Replication and examination of neurophysiologic mechanisms underlying alcohol use in the context of MA dependence are warranted to elucidate whether alcohol confers a degree of neuroprotection.

Cognitive function in aging cocaine smokers

BACKGROUND

Little is known about the functional status of older drug users, who may pose challenges to public health systems in coming years. Here, we assessed cognitive function in aging cocaine smokers compared to demographically matched controls.

METHODS

A total of 22 non-treatment-seeking aging (50-60 years old) cocaine smokers (⩾twice/week; ⩾15 years of weekly use) and 19 controls completed a comprehensive cognitive battery. Controls with cannabis, tobacco, and alcohol use were included to better match the cocaine users. All cocaine users, and current cannabis- or alcohol-using controls, completed testing after 4 drug-free inpatient days to better control for acute and residual drug effects.

RESULTS

Cocaine users (52.9 ± 2.5 years old, four female; cocaine use 3.9 ± 1.4 days/week) and controls (52.7 ± 2.6 years old, four female) were well matched demographically, but cocaine users reported a more extensive substance use profile. Cocaine users showed marginally worse verbal learning than controls, recalling on average one word fewer across immediate and delayed word recall trials. Their performance was intact relative to controls across all other measures of cognitive function. Bayesian analysis indicated the absence of group differences was not due to power limitations.

CONCLUSION

These data suggest that aging, long-term cocaine users have similar cognitive functioning to appropriately matched controls when tested under drug-free conditions, with only marginal decreases in verbal learning. Findings, although reassuring with regard to broad cognitive capacities in aging cocaine smokers, suggest that future investigations of cognitive function in aging drug users are warranted.

Cognitive dysfunction in individuals with cocaine use disorder: Potential moderating factors and pharmacological treatments

It is well-documented in the literature that individuals repeatedly exposed to cocaine exhibit cognitive impairment and that cognitive dysfunction is a risk factor for poor treatment outcomes in those with cocaine use disorder (CUD). Specific deficits related to attention, episodic memory, working memory, and executive functioning are the most common deficits noted in this population. Given that cognitive impairment is a risk factor for poor treatment outcomes in those with CUD, identifying possible moderating factors contributing to and/or exacerbating cocaine-related cognitive deficits is of great importance. Some of these factors may include premorbid intellectual functioning, cocaine use patterns, polysubstance use, comorbid emotional symptoms, and sleep dysfunction. It is plausible that by identifying moderating factors impacting cognition, behavioral interventions can then be modified accordingly and/or treatment regimens can be augmented with pharmacological interventions (e.g., cognitive enhancing agents), leading to a reduction in treatment attrition and improved treatment outcomes. The currently available treatments for CUD are mainly behavioral with variable efficacy, and even though there have been great preclinical and clinical research efforts focused on medication development for CUD, there are currently no Food and Drug Administration-approved medications for CUD. A description of some of the several potential moderating factors, along with some pharmacological treatments which have been shown to ameliorate, at least to some extent, cognitive dysfunction in those with CUD are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Alcohol Interaction with Cocaine, Methamphetamine, Opioids, Nicotine, Cannabis, and γ-Hydroxybutyric Acid

Millions of people around the world drink alcoholic beverages to cope with the stress of modern lifestyle. Although moderate alcohol drinking may have some relaxing and euphoric effects, uncontrolled drinking exacerbates the problems associated with alcohol abuse that are exploding in quantity and intensity in the United States and around the world. Recently, mixing of alcohol with other drugs of abuse (such as opioids, cocaine, methamphetamine, nicotine, cannabis, and γ-hydroxybutyric acid) and medications has become an emerging trend, exacerbating the public health concerns. Mixing of alcohol with other drugs may additively or synergistically augment the seriousness of the adverse effects such as the withdrawal symptoms, cardiovascular disorders, liver damage, reproductive abnormalities, and behavioral abnormalities. Despite the seriousness of the situation, possible mechanisms underlying the interactions is not yet understood. This has been one of the key hindrances in developing effective treatments. Therefore, the aim of this article is to review the consequences of alcohol's interaction with other drugs and decipher the underlying mechanisms.

Neuropsychological Performance in Alcohol Dependent Patients: A One-Year Longitudinal Study

OBJECTIVE

Despite several studies that have highlighted the harmful effects of alcohol consumption on cognitive functions it remains unclear whether certain brain areas are more sensitive than others are or whether alcohol causes widespread cognitive deficit. Moreover, the role of continued abstinence has yet to be clarified regarding the quality of recovery on the different cognitive domains. The aim of this 1-year longitudinal study was to evaluate the recovery of cognitive deficits in the medium (6 months) and long term (12 months) after the interruption of drinking.

METHODS

Forty-one alcohol-dependent patients were recruited from two outpatient treatment facilities and cognitive functions were compared on a control group of forty healthy controls. The patients were then re-assessed at 6 and 12 months. Changes in neuropsychological measures were evaluated with repeated measures analysis of variance (ANOVA). We also compared 1-year follow-up scores with control data (unpaired t tests) to identify tests on which significant differences persisted.

RESULTS

Patients performed significantly worse than controls in all cognitive domains investigated and this cognitive impairment was evident in recently abstinent patients. A year of abstinence resulted in a significant improvement in all cognitive domains assessed after detoxification from alcohol. After year 1, alcoholic subjects had returned to normal levels compared to healthy controls on all domains except for general non-verbal intelligence, verbal memory and some visuospatial skills.

CONCLUSION

Our results support the hypothesis of widespread impairment resulting from alcohol consumption. The recovery of cognitive functions is not homogeneous during prolonged abstinence.

Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods

One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.

Animal models of drug addiction: Where do we go from here?

Compulsion and impulsivity are both primary features of drug addiction. Based on decades of animal research, we have a detailed understanding of the factors (both environmental and physiological) that influence compulsive drug use, but still know relatively little about the impulsive aspects of drug addiction. This review outlines our current knowledge of the relationship between impulsivity and drug addiction, focusing on cognitive and motor impulsivity, which are particularly relevant to this disorder. Topics to be discussed include the influence of chronic drug administration on impulsivity, the mechanisms that may explain drug-induced impulsivity, and the role of individual differences in the development of impulsive drug use. In addition, the manner in which contemporary theories of drug addiction conceptualize the relationship between impulsivity and compulsion is examined. Most importantly, this review emphasizes a critical role for animal research in understanding the role of impulsivity in the development and maintenance of drug addiction.

Correlation between Blood and Oral Fluid Psychoactive Drug Concentrations and Cognitive Impairment in Driving under the Influence of Drugs

BACKGROUND

The effects of drugs on driving performance should be checked with drug concentration in the brain and at the same time with the evaluation of both the behavioural and neurophysiological effects. The best accessible indicator of this information is the concentration of the drug and/or metabolites in blood and, to a certain extent, oral fluid. We sought to review international studies on correlation between blood and oral fluid drug concentrations, neurological correlates and cognitive impairment in driving under the influence of drugs.

METHODS

Relevant scientific articles were identified from PubMed, Cochrane Central, Scopus, Web of Science, Science Direct, EMBASE up to April 2017.

RESULTS

Up to 2010, no epidemiological studies were available on this matter and International scientists suggested that even minimal amounts of parent drugs in blood and oral fluid could affect driving impairment. More recently, epidemiological data, systematic reviews and meta-analysis on drugged drivers allowed the suggestion of impairment concentration limits for the most common illicit drugs. These values were obtained comparing driving disability induced by psychotropic drugs with that of established blood alcohol limits. Differently from ethyl alcohol where both detection methods and concentration limits have been well established even with inhomogeneity of ranges within different countries, in case of drugs of abuse no official cut-offs have yet been established, nor any standardized analytical protocols.

CONCLUSION

Multiple aspects of driving performance can be differently affected by illicit drugs, and even if for few of them some dose/concentration dependent impairment has been reported, a wider knowledge on concentration/impairment relationship is still missing.

Self-reported cognitive scales in a US National Survey: reliability, validity, and preliminary evidence for associations with alcohol and drug use

AIMS

To evaluate relationships between measures of cognitive functioning and alcohol or drug use among adults (≥ 18 years) in the US general population.

DESIGN

Two cognitive scales were created based on dimensionality and reliability of self-reported Executive Function Index items. Relationships between the two scales and validators were evaluated. Associations between the cognitive scales and past-year frequency of alcohol or drug use were estimated with adjusted odds ratios (aOR).

SETTING

United States, using the 2012-13 National Epidemiologic Survey on Alcohol and Related Conditions-III, a nationally representative adult sample selected by multi-stage probability sampling.

PARTICIPANTS

36 085 respondents.

MEASUREMENTS

Past-year substance use outcome variables categorized binge drinking, marijuana, cocaine, opioid, sedative/tranquilizer and stimulant use as frequent (at least weekly to daily), infrequent (any to two to three times/month) or no use, assessed by the Alcohol Use Disorder and Associated Disabilities Interview Schedule-5. Key predictors were the two cognitive scales. Construct validators included education and functional impairment. Covariates included age, gender, income and race/ethnicity.

FINDINGS

Nine cognitive items fitted a two-factor model (comparative fit index = 0.973): attention (five items) and executive functioning (four items). Both scales were associated positively with higher education (Ps < 0.001) and negatively with functional impairment (Ps < 0.001), demonstrating construct validity. Poorer attention was associated with frequent and infrequent binge drinking and use of drugs [aOR range = 1.07 (binge drinking) to 1.72 (stimulants), Ps ≤ 0.01]. Poorer executive functioning was associated with frequent binge drinking and use of drugs [aOR range = 1.22 (binge drinking) to 2.03 (cocaine), Ps < 0.001] and infrequent use of all drugs [aOR range = 1.19 (marijuana) to 1.63 (cocaine), Ps < 0.001].

CONCLUSIONS

Impairments in attention and executive functioning are positively associated with substance use in the US general population.

Atomoxetine in abstinent cocaine users: Cognitive, subjective and cardiovascular effects

No pharmacotherapies are approved for the treatment of cocaine use disorders (CUD). Behavioral treatments for CUD are efficacious for some individuals, but recovery rates from CUD remain low. Cognitive impairments in CUD have been linked with poorer clinical outcomes. Cognitive enhancing pharmacotherapies have been proposed as promising treatments for CUD. Atomoxetine, a norepinephrine transporter inhibitor, shows potential as a treatment for CUD based on its efficacy as a cognitive enhancer in other clinical populations and impact on addictive processes in preclinical and human laboratory studies. In this randomized, double-blind, crossover study, abstinent individuals with CUD (N=39) received placebo, 40 and 80mg atomoxetine, over three sessions. Measures of attention, response inhibition and working memory; subjective medication effects and mood; and cardiovascular effects were collected. Analyses assessed acute, dose-dependent effects of atomoxetine. In addition, preliminary analyses investigating the modulation of atomoxetine dose effects by sex were performed. Atomoxetine increased heart rate and blood pressure, was rated as having positive and negative subjective drug effects, and had only modest effects on mood and cognitive enhancement.

Longitudinal Modeling of Depressive Trajectories Among HIV-Infected Men Using Cocaine

Cocaine use is prevalent among HIV-infected individuals. While cross-sectional studies suggest that cocaine users may be at increased risk for depression, long-term effects of cocaine on depressive symptoms remain unclear. This is a longitudinal study of 341 HIV-infected and uninfected men (135 cocaine users and 206 controls) ages 30-60 enrolled in the Multicenter AIDS Cohort Study during 1996-2009. The median baseline age was 41; 73% were African-American. In mixed-effects models over a median of 4.8 years of observation, cocaine use was associated with higher depressive symptoms independent of age, education level, and smoking (n = 288; p = 0.02); HIV infection modified this association (p = 0.03). Latent class mixed models were used to empirically identify distinct depressive trajectories (n = 160). In adjusted models, cocaine use was associated with threefold increased odds of membership in the class with persistent high depressive symptoms (95% confidence interval (CI) 1.38-6.69) and eightfold increased odds (95% CI (2.73-25.83) when tested among HIV-infected subjects only. Cocaine use is a risk factor for chronic depressive symptoms, particularly among HIV-infected men, highlighting the importance of integrating mental health and substance use treatments to address barriers to well-being and successful HIV-care.

The Complex Nature of Parental Substance Use: Examining Past Year and Prior Use Behaviors as Correlates of Child Maltreatment Frequency

BACKGROUND

Child maltreatment studies predominantly have operationalized parental substance use as dichotomous variables for any use, any harmful/risky use, or any substance use disorder (SUD). This limits our understanding about how a range of use behaviors may contribute to child maltreatment.

OBJECTIVE

Build upon prior studies by incorporating a multi-faceted approach to operationalizing parental substance use.

METHODS

Cross-sectional, secondary data analyses were conducted using the National Survey of Child and Adolescent Well-being (NSCAW I). The study used weighted negative binomial regression to examine relationships between annual child maltreatment frequency and different ways of operationalizing substance use among 2,100 parents.

RESULTS

Several, inter-related behaviors (i.e., heavy drinking, illicit drug use, polysubstance use, SUD, and prior SUD < 4 years) appeared to be relevant for understanding differences in child maltreatment frequencies. A gradient effect was detected across five substance use behavior patterns: (1) lowest estimated counts were observed for nonusers, light-to-moderate drinkers, and parents with a prior (but not past year) SUD (ӯ < 7.0), (2) slightly higher estimated count was observed for heavy drinkers and/or illicit drug users (ӯ = 9.3), and (3) highest estimated count was observed for parents with past year SUD (ӯ = 17.6). Conclusions/Importance: SUD is a critical screening criteria for potential child harm. Parents reporting risky substance use behaviors may benefit from prevention or brief intervention services related to both their substance use and parenting behaviors. Administrative systems also could benefit from detailed tracking of substance use behaviors for future program evaluation and development.

Differential Improvement of Executive Functions During Abstinence in Cocaine-Dependent Patients: A Longitudinal Study

BACKGROUND

In substance abusers, deficits in executive functioning (EF) are relevant to understanding the behavioral regulation of substance consumption and the failure to remain abstinent.

OBJECTIVE

To determine the course of EF impairment, measured with traditional and ecological instruments, after 1 and 3 months of abstinence in patients with cocaine dependence.

METHODS

26 cocaine-only-dependent in-patients (cocaine-dependent group, CDG) and 24 nondependent controls (control group, CG) recruited from a typical population were assessed using several EF tests and questionnaires [Stroop, verbal and graphic fluency, Wisconsin Card-Sorting Test (WCST), Tower of London (TOL), and Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A)] after three periods of abstinence: 1 week, 1 month, and 3 months.

RESULTS

At 1 week (baseline), CDG underperformed CG on most EF measures (WCST categories completed; TOL-total number of moves, execution time, and rule violations; and various BRIEF-A subscales). At 1 month, CDG moderately improved its performance on several measures, meanwhile the improvement in the 12 patients who would eventually complete the 3-month abstinence proved particularly significant when compared to their baseline values. In the a posteriori comparison of the baseline values of noncompleters versus completers, scores for the former were lower on the EF tasks, but higher on the BRIEF-A. Both groups, showed significantly worse scores than CG on both instruments.

CONCLUSIONS/IMPORTANCE

Cocaine-dependent patients showed marked difficulties in the EF associated mainly with adaptive behavior to their environment. Cocaine-dependent patients with better EF at baseline improved significantly during abstinence and had better treatment adherence. Results suggest that executive improvement and treatment adherence in cocaine abusers in abstinence is related to intrinsic cognitive characteristics of patients.

Alcohol Interactions with Psychostimulants: An Overview of Animal and Human Studies

Alcohol consumption with psychostimulants is very common among drug addicts. There is little known about the possible pharmacological interactions between alcohol and psychostimulants. Among most commonly co-abused psychostimulants with alcohol are methamphetamine, cocaine, 3,4-methylenedioxymethamphetaminen, and nicotine. Co-abuse of alcohol with psychostimulants can lead to several neurophysiological dysfunctions such as decrease in brain antioxidant enzymes, disruption of learning and memory processes, cerebral hypo-perfusion, neurotransmitters depletion as well as potentiation of drug seeking behaviour. Moreover, co-abuse of alcohol and psychostimulants can lead to increase in heart rate, blood pressure, myocardial oxygen consumption and cellular stress, and the risk of developing different types of cancer. Co-abuse of alcohol with psychostimulants during pregnancy can lead to fetal brain abnormalities. Further studies are needed to investigate the pharmacokinetics, pharmacodynamics, and neurochemical changes on co-abuse of alcohol and psychostimulants.

Risky Decisions in a Lottery Task Are Associated with an Increase of Cocaine Use

Cocaine use disorder is associated with maladaptive decision-making behavior, which strongly contributes to the harmful consequences of chronic drug use. Prior research has shown that cocaine users exhibit impaired neuropsychological test performances, particularly with regard to attention, learning, and memory but also in executive functions such as decision-making and impulse control. However, to what extent cocaine users show impaired decision-making under risk without feedback has not yet been investigated systematically. Therefore, to examine risk-taking behavior, 31 chronic cocaine users and 26 stimulant-naïve healthy controls who were part of the Zurich Cocaine Cognition Study, performed the Randomized Lottery Task (RALT) with winning lotteries consisting of an uncertain and a certain prospect. Results revealed that risky decisions were associated with male sex, increased cocaine use in the past year, higher cocaine concentrations in the hair, and younger age. In addition, higher levels of cocaine in the hair and cumulative lifetime consumption were associated with risky decisions, whereas potentially confounding factors including cognition and psychiatric symptoms had no significant effect. Taken together, our results indicate that cocaine users who increased their consumption over a period of 1 year show deficits in the processing of risky information accompanied with increased risk-taking. Future research should analyse whether risky decisions could potentially serve as a prognostic marker for cocaine use disorder.

Visual and verbal learning deficits in Veterans with alcohol and substance use disorders

BACKGROUND

This study examined visual and verbal learning in the early phase of recovery for 48 Veterans with alcohol use (AUD) and substance use disorders (SUD, primarily cocaine and opiate abusers). Previous studies have demonstrated visual and verbal learning deficits in AUD, however little is known about the differences between AUD and SUD on these domains. Since the DSM-5 specifically identifies problems with learning in AUD and not in SUD, and problems with visual and verbal learning have been more prevalent in the literature for AUD than SUD, we predicted that people with AUD would be more impaired on measures of visual and verbal learning than people with SUD.

METHODS

Participants were enrolled in a comprehensive rehabilitation program and were assessed within the first 5 weeks of abstinence. Verbal learning was measured using the Hopkins Verbal Learning Test (HVLT) and visual learning was assessed using the Brief Visuospatial Memory Test (BVMT).

RESULTS

Results indicated significantly greater decline in verbal learning on the HVLT across the three learning trials for AUD participants but not for SUD participants (F=4.653, df=48, p=0.036). Visual learning was less impaired than verbal learning across learning trials for both diagnostic groups (F=0.197, df=48, p=0.674); there was no significant difference between groups on visual learning (F=0.401, df=14, p=0.538).

DISCUSSION

Older Veterans in the early phase of recovery from AUD may have difficulty learning new verbal information. Deficits in verbal learning may reduce the effectiveness of verbally-based interventions such as psycho-education.

Offenders with Cognitive Deficits in a Canadian Prison Population: Prevalence, Profile, and Outcomes

Impaired cognitive function has been associated with criminal behavior. In Canada it is unknown the extent to which this disorder affects federal inmates or its impact on key correctional outcomes. In this study, 488 incoming male offenders were assessed on the Cognistat, a neuropsychological screening tool. Twenty-five percent of offenders were found to have some level of cognitive deficit. Lower levels of educational achievement, unstable employment history, learning disability, serious alcohol problems, and symptoms of Attention Deficit Hyperactivity Disorder (ADHD) were significantly associated with the presence of cognitive deficits in this sample. Although there was a significant trend for offenders with cognitive deficits to have more admissions to segregation, level of cognitive deficit was not consistently related to rates of institutional charges or rates of completion of required correctional programs. On release, cognitive deficits were not related to returns to custody or returns to custody with an offence. These results indicate that while offenders with cognitive deficits may require assistance with educational upgrading and employment to improve their reintegration potential, they do not pose a particular management problem in the community after release relative to offenders without cognitive deficits.

A new exposure model to evaluate smoked illicit drugs in rodents: A study of crack cocaine

The use of smoked illicit drugs has spread dramatically, but few studies use proper devices to expose animals to inhalational abused drugs despite the availability of numerous smoking devices that mimic tobacco exposure in rodents. Therefore, the present study developed an inexpensive device to easily expose laboratory animals to smoked drugs. We used crack cocaine as the drug of abuse, and the cocaine plasma levels and the behaviors of animals intoxicated with the crack cocaine were evaluated to prove inhaled drug absorption and systemic activity. We developed an acrylic device with two chambers that were interconnected and separated by a hatch. Three doses of crack (100, 250, or 500 mg), which contained 63.7% cocaine, were burned in a pipe, and the rats were exposed to the smoke for 5 or 10 min (n=5/amount/period). Exposure to the 250-mg dose for 10 min achieved cocaine plasma levels that were similar to those of users (170 ng/mL). Behavioral evaluations were also performed to validate the methodology. Rats (n=10/group) for these evaluations were exposed to 250 mg of crack cocaine or air for 10 min, twice daily, for 28 consecutive days. Open-field evaluations were performed at three different periods throughout the experimental design. Exposed animals exhibited transient anorexia, increased motor activity, and shorter stays in central areas of the open field, which suggests reduced anxiety. Therefore, the developed model effectively exposed animals to crack cocaine, and this model may be useful for the investigation of other inhalational abused drugs.

Epigenetics of Stress, Addiction, and Resilience: Therapeutic Implications

Substance use disorders (SUDs) are highly prevalent. SUDs involve vicious cycles of binges followed by occasional periods of abstinence with recurrent relapses despite treatment and adverse medical and psychosocial consequences. There is convincing evidence that early and adult stressful life events are risks factors for the development of addiction and serve as cues that trigger relapses. Nevertheless, the fact that not all individuals who face traumatic events develop addiction to licit or illicit drugs suggests the existence of individual and/or familial resilient factors that protect these mentally healthy individuals. Here, I give a brief overview of the epigenetic bases of responses to stressful events and of epigenetic changes associated with the administration of drugs of abuse. I also discuss the psychobiology of resilience and alterations in epigenetic markers that have been observed in models of resilience. Finally, I suggest the possibility that treatment of addiction should involve cognitive and pharmacological approaches that enhance resilience in at risk individuals. Similar approaches should also be used with patients who have already succumbed to the nefarious effects of addictive substances.

Distress Tolerance: Associations With Posttraumatic Stress Disorder Symptoms Among Trauma-Exposed, Cocaine-Dependent Adults

The present investigation examined associations between distress tolerance and posttraumatic stress disorder (PTSD) symptoms in a cocaine-dependent sample. Participants were comprised of 138 cocaine-dependent adults (Mage = 45.4, SD = 9.9; 81% male; 76.3% African American) who endorsed trauma exposure, defined according to Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR) PTSD Criterion A. Participants were administered interview-based measures and completed a series of self-report questionnaires. Results indicated that distress tolerance was significantly, incrementally (negatively) associated with PTSD symptom severity, contributing 6.8% of unique variance to the model (p < .001); notably, the overall model explained 44.8% of variance in PTSD symptomatology. Distress tolerance also contributed between 2.7% and 6.8% of unique variance across each of the PTSD symptom clusters (ps < .05). Incremental effects were documented, after accounting for the variance explained by theoretically relevant covariates (i.e., gender, cocaine-use severity, depressive symptoms, trauma-exposure severity). Theoretical and clinical implications are discussed.

Competing neurobehavioral decision systems theory of cocaine addiction: From mechanisms to therapeutic opportunities

Cocaine dependence is a difficult-to-treat, chronically relapsing disorder. Multiple scientific disciplines provide distinct perspectives on this disorder; however, connections between disciplines are rare. The competing neurobehavioral decision systems (CNDS) theory posits that choice results from the interaction between two decision systems (impulsive and executive) and that regulatory imbalance between systems can induce pathology, including addiction. Using this view, we integrate a diverse set of observations on cocaine dependence, including bias for immediacy, neural activity and structure, developmental time course, behavioral comorbidities, and the relationship between cocaine dependence and socioeconomic status. From the CNDS perspective, we discuss established and emerging behavioral, pharmacological, and neurological treatments and identify possible targets for future treatments. The ability of the CNDS theory to integrate diverse findings highlights its utility for understanding cocaine dependence and supports that dysregulation between the decision systems contributes to addiction.

CRF₂ receptor-deficiency reduces recognition memory deficits and vulnerability to stress induced by cocaine withdrawal

Psychostimulant drug abuse, dependence and withdrawal are associated with cognitive dysfunction and impact stress-sensitive systems. The corticotropin-releasing factor (CRF) system orchestrates stress responses via CRF1 and CRF2 receptors and is implicated in substance use disorders. However, CRF2 role in psychostimulant drug-induced cognitive dysfunction remains to be elucidated. In the present study, wild-type and CRF2-/- mice are injected with cocaine and memory assessed by the novel object recognition (NOR) task throughout relatively long periods of drug withdrawal. Following recovery from the drug-induced memory deficits, the mice are stressed prior to the NOR task and brain gene expression evaluated by in situ hybridization. Cocaine impairs NOR memory in wild-type and CRF2-/- mice. However, following cocaine withdrawal NOR memory deficits last less time in CRF2-/- than in wild-type mice. Furthermore, a relatively mild stressor induces the re-emergence of NOR deficits in long-term cocaine-withdrawn wild-type but not CRF2-/- mice. Cocaine-withdrawn mice show a genotype-independent higher c-fos expression in the NOR memory-relevant perirhinal cortex than drug-naïve mice. However neither genotype nor drug withdrawal affect the expression of tyrosine hydroxylase in the ventral tegmental area or the locus coeruleus and CRF in the central nucleus of the amygdala or the paraventricular nucleus of the hypothalamus, brain regions implicated in stress and drug responses. These data indicate a new role for the CRF2 receptor in cognitive deficits induced by cocaine withdrawal, both as regards to their duration and their re-induction by stress. Interestingly, prototypical brain stress systems other than CRF do not appear to be involved.

Relationship between trait impulsivity and cortical volume, thickness and surface area in male cocaine users and non-drug using controls

BACKGROUND

Trait impulsivity is commonly associated with cocaine dependence. The few studies that have investigated the relation between trait impulsivity and cortical morphometry, have shown a distinct relation between impulsivity and cortical volume (CV) of temporal, frontal and insula cortex. As CV is the function of cortical surface area (SA) and cortical thickness (CT) impulsivity may be differently associated to SA than to CT.

METHOD

Fifty-three cocaine users (CU) and thirty-five controls (HC) (males aged 18-55 years) completed the Barrat impulsiveness scale and a structural scan was made on a 3T MRI scanner. CV, SA and CT were measured using Freesurfer. Multivariate analysis was used to test for group differences and group by impulsivity interaction effects in CV, SA and ST across nine regions of interest in the temporal, frontal and insular cortices. Possible confounding effects of drug- and alcohol exposure were explored.

RESULTS

Compared to HC, CU had a smaller SA of the superior temporal cortex but a larger SA of the insula. There were divergent relations between trait impulsivity and SA of the superior temporal cortex and insula (positive in HC, negative in CU) and CT of the anterior cingulate cortex (negative in HC, positive in CU). Within CU, there was a negative association between monthly cocaine use and CT of the insula and superior temporal cortex.

DISCUSSION

The distinct relation between trait impulsivity and cortical morphometry in CU and HC might underlie inefficient control over behavior resulting in maladaptive impulsive behaviour such as cocaine abuse.

Cognitive impairment in cocaine users is drug-induced but partially reversible: evidence from a longitudinal study

Cocaine users consistently display cognitive impairments. However, it is still unknown whether these impairments are cocaine-induced and if they are reversible. Therefore, we examined the relation between changing intensity of cocaine use and the development of cognitive functioning within 1 year. The present data were collected as part of the longitudinal Zurich Cocaine Cognition Study (ZuCo(2)St). Forty-eight psychostimulant-naive controls and 57 cocaine users (19 with increased, 19 with decreased, and 19 with unchanged cocaine use) were eligible for analysis. At baseline and after a 1-year follow-up, cognitive performance was measured by a global cognitive index and four neuropsychological domains (attention, working memory, declarative memory, and executive functions), calculated from 13 parameters of a broad neuropsychological test battery. Intensity of cocaine use was objectively determined by quantitative 6-month hair toxicology at both test sessions. Substantially increased cocaine use within 1 year (mean +297%) was associated with reduced cognitive performance primarily in working memory. By contrast, decreased cocaine use (-72%) was linked to small cognitive improvements in all four domains. Importantly, users who ceased taking cocaine seemed to recover completely, attaining a cognitive performance level similar to that of the control group. However, recovery of working memory was correlated with age of onset of cocaine use-early-onset users showed hampered recovery. These longitudinal data suggest that cognitive impairment might be partially cocaine-induced but also reversible within 1 year, at least after moderate exposure. The reversibility indicates that neuroplastic adaptations underlie cognitive changes in cocaine users, which are potentially modifiable in psychotherapeutical or pharmacological interventions.

Crack cocaine use impairs anterior cingulate and prefrontal cortex function in women with HIV infection

Crack cocaine use is associated with impaired verbal memory in HIV-infected women more than uninfected women. To understand the neural basis for this impairment, this study examined the effects of crack cocaine use on activation of the prefrontal cortex (PFC) and strategic encoding during a verbal memory task in HIV-infected women. Three groups of HIV-infected women from the Chicago Consortium of the Women's Interagency HIV Study were compared: current users of crack cocaine (n = 10), former users of cocaine (n = 11), and women who had never used cocaine (n = 9). Participants underwent functional magnetic resonance imaging during a verbal memory task and completed a neuropsychological test of verbal memory. On the neuropsychological test, current crack users performed significantly worse than other groups on semantic clustering, a measure of strategic encoding, p < 0.05. During encoding, activation in left anterior cingulate cortex (ACC) was lower in current and former cocaine users compared to never users. During recognition, activation in bilateral PFC, specifically left dorsal medial PFC and bilateral dorsolateral PFC, was lower in current and former users compared to women who had never used cocaine. Lower activation in left dorsolateral PFC was correlated with worse performance on the recognition task, p < 0.05. The verbal learning and memory deficits associated with cocaine use in women with HIV may be partially accounted for by alterations in ACC and PFC function.

The involvement of secondary neuronal damage in the development of neuropsychiatric disorders following brain insults

Neuropsychiatric disorders are one of the leading causes of disability worldwide and affect the health of billions of people. Previous publications have demonstrated that neuropsychiatric disorders can cause histomorphological damage in particular regions of the brain. By using a clinical symptom-comparing approach, 55 neuropsychiatric signs or symptoms related usually to 14 types of acute and chronic brain insults were identified and categorized in the present study. Forty percent of the 55 neuropsychiatric signs and symptoms have been found to be commonly shared by the 14 brain insults. A meta-analysis supports existence of the same neuropsychiatric signs or symptoms in all brain insults. The results suggest that neuronal damage might be occurring in the same or similar regions or structures of the brain. Neuronal cell death, neural loss, and axonal degeneration in some parts of the brain (the limbic system, basal ganglia system, brainstem, cerebellum, and cerebral cortex) might be the histomorphological basis that is responsible for the neuropsychiatric symptom clusters. These morphological alterations may be the result of secondary neuronal damage (a cascade of progressive neural injury and neuronal cell death that is triggered by the initial insult). Secondary neuronal damage causes neuronal cell death and neural injury in not only the initial injured site but also remote brain regions. It may be a major contributor to subsequent neuropsychiatric disorders following brain insults.

HIV and recent illicit drug use interact to affect verbal memory in women

OBJECTIVE

HIV infection and illicit drug use are each associated with diminished cognitive performance. This study examined the separate and interactive effects of HIV and recent illicit drug use on verbal memory, processing speed, and executive function in the multicenter Women's Interagency HIV Study.

METHODS

Participants included 952 HIV-infected and 443 HIV-uninfected women (mean age = 42.8, 64% African-American). Outcome measures included the Hopkins Verbal Learning Test-Revised and the Stroop test. Three drug use groups were compared: recent illicit drug users (cocaine or heroin use in past 6 months, n = 140), former users (lifetime cocaine or heroin use but not in past 6 months, n = 651), and nonusers (no lifetime use of cocaine or heroin, n = 604).

RESULTS

The typical pattern of recent drug use was daily or weekly smoking of crack cocaine. HIV infection and recent illicit drug use were each associated with worse verbal learning and memory (P < 0.05). Importantly, there was an interaction between HIV serostatus and recent illicit drug use such that recent illicit drug use (compared with nonuse) negatively impacted verbal learning and memory only in HIV-infected women (P < 0.01). There was no interaction between HIV serostatus and illicit drug use on processing speed or executive function on the Stroop test.

CONCLUSIONS

The interaction between HIV serostatus and recent illicit drug use on verbal learning and memory suggests a potential synergistic neurotoxicity that may affect the neural circuitry underlying performance on these tasks.

Neurocognition in 1-month-abstinent treatment-seeking alcohol-dependent individuals: interactive effects of age and chronic cigarette smoking

BACKGROUND

Increasing age and chronic cigarette smoking are independently associated with adverse effects on multiple aspects of neurocognition in those seeking treatment for alcohol use disorders. However, the potential interactive effects of age and cigarette smoking on neurocognition in early abstinent alcohol-dependent individuals (ALC) have not investigated.

METHODS

Cross-sectional performances of never-smoking healthy comparison participants (nvsCOM; n = 39) and 1-month-abstinent, treatment-seeking, never-smoking (nvsALC; n = 30), former-smoking (fsALC; n = 21), and actively smoking (asALC; n = 68) ALC were compared on a comprehensive neurocognitive battery. Domains of functioning evaluated were cognitive efficiency, executive functions, fine motor skills, general intelligence, learning and memory, processing speed, visuospatial functions and working memory. Participants were between 26 and 71 years of age at the time of assessment.

RESULTS

asALC showed steeper age-related effects than nvsCOM on the domains of visuospatial learning, auditory-verbal memory, cognitive efficiency, executive functions, processing speed, and fine motor skills. In pairwise comparisons, fsALC and asALC performed more poorly than both nvsCOM and nvsALC on multiple domains; nvsCOM and nvsALC showed no significant differences. Domain scores for the ALC groups generally fell in the low-to-high-average range of functioning. A clinically significant level of impairment was apparent in only 25% of ALC participants on visuospatial learning, visuospatial memory, and fine motor skills domains. Measures of alcohol use or consumption were not significantly related to neurocognition in the ALC cohorts.

CONCLUSIONS

The age-related findings suggest that the combination of active chronic smoking and alcohol dependence in this 1-month-abstinent ALC cohort was associated with greater than normal age-related effects in multiple domains. In general, a low level of clinically significant impairment was observed in the alcohol-dependent participants. The findings from this study, in conjunction with previous research, strongly support smoking cessation interventions for those seeking treatment for alcohol and substance use disorders.

Relationship between sex hormones and cognitive performance in men with substance use

BACKGROUND

Hypogonadism is common with opiate-like drug use and may contribute to cognitive abnormalities. With the increasing epidemic of HIV and substance use (SU) worldwide, it is important to understand the impact of these conditions on cognition, which may affect quality of life and possibly decrease adherence to treatment. We hypothesized that men with SU, by virtue of hypogonadism secondary to HIV and/or SU, may demonstrate impaired cognition.

METHODS

We recruited men aged 18-50 from a population of low income, inner-city individuals. Details of HIV and SU status, serum blood levels of total testosterone (TT), free testosterone (FT) and estradiol (E2) were assessed. All subjects were administered ten neuropsychological tests.

RESULTS

Our sample consisted of 68 men (mean age: 43.2 years (SD 5.8), African Americans: 86.6%). The recruited population was primarily from low socioeconomic status and unemployed. The mean level of TT was 553.9 ng/dL (SD 262.0), the mean level of FT was 69.5 pg/mL (SD 34.8), mean E2 was 3.2 pg/mL (SD 4.4). We found that 30.9% were hypogonadal and it was associated with higher SU. We observed some relationships between sex hormones and cognitive domains, however, after adjustment for age, drug use category, education, depression, HIV, there was no statistically significant correlation between cognitive performance and sex hormone levels.

CONCLUSIONS

In this cross-sectional study of men with a high prevalence of SU and hypogonadism, endogenous levels of TT, FT or E2 were not related to cognitive performance. Other factors need to be identified which may contribute to poor cognitive function in the setting of SU.

A randomized, controlled, pilot trial of methylphenidate and cognitive-behavioral group therapy for cocaine dependence in heroin prescription

Cocaine dependence has proved difficult to treat, whether it occurs alone or in combination with opiate dependence. No intervention has been demonstrated to be uniquely effective. Patients might benefit most from combined pharmacotherapeutic and psychotherapeutic interventions. The present study sought to evaluate the feasibility, tolerability, and efficacy of methylphenidate (MP) and cognitive-behavioral group therapy (CBGT) for cocaine dependence in diacetylmorphine-maintained patients. Sixty-two cocaine-dependent diacetylmorphine-maintained patients participated in a dual-site, double-blind, placebo-controlled pilot trial with 4 treatment conditions. The participants were randomly assigned to receive MP or a placebo each combined with either CBGT or treatment as usual for 12 weeks. Methylphenidate 30 mg and a placebo in identical capsules were administered onsite twice daily under supervision in a fixed-dose regimen without titration. Manual-guided CBGT consisted of 12 weekly sessions. Participation in the CBGT sessions was voluntary. Primary outcome measures were retention in pharmacologic treatment, cocaine-free urine samples, self-reported cocaine use, and adverse effects. Urine screens were performed thrice weekly. Seventy-one percent of the participants completed the study protocol. Methylphenidate was well tolerated with similar retention rates compared with the placebo. No serious adverse effects occurred. No difference in cocaine-free urine screens was found across the 4 treatment groups. Self-reported cocaine use was reduced in all 4 study groups. Methylphenidate and CBGT did not provide an advantage over a placebo or treatment as usual in reducing cocaine use. There were no signs of additive benefits of MP and CBGT. Because of the small sample size, the results are preliminary.

A model of school problems, academic failure, alcohol initiation, and the relationship to adult heroin injection

The current study uses structural equation modeling to investigate factors associated with alcohol initiation and injection heroin use. Baseline data from the NEURO-HIV Epidemiologic Study in Baltimore, Maryland, were used. Participants were 404 injection heroin users (M(age) = 32.72) with a history of regular injection in their lifetime. Latent variables were created for self-reported school problems and academic failure. The final model indicated that greater school problems were associated with earlier alcohol initiation (ß = -0.22, p < .001) and earlier alcohol initiation was associated with greater frequency of recent heroin use (ß = -0.12, p < .05). Academic failure was directly related to greater frequency of recent heroin injection (ß = 0.15, p < .01). The results expand research investigating the relationship between adolescent behavior and illicit drug use in adulthood.

A preliminary study of the neural effects of behavioral therapy for substance use disorders

BACKGROUND

The mechanisms by which behavioral therapies for substance use disorders (SUDs) exert their effects and the components of treatment that contribute most to substance use outcome remain unclear. Disruptions to aspects of impulse control and attention have been hypothesized to contribute to the development and maintenance of addiction; moreover, alterations in these processes may underlie responses to treatment.

METHODS

Individuals participating in a randomized clinical trial evaluating computer-assisted cognitive behavioral therapy (CBT) for substance abuse participated in fMRI Stroop before and after treatment. A non-substance-using comparison group performed the same task under test-retest conditions.

RESULTS

The patient group demonstrated decreased Stroop-related BOLD signal in regions including the anterior cingulate, inferior frontal gyrus and midbrain at post-treatment relative to pre-treatment, and displayed a greater decrease in the subthalamic nucleus and surrounding regions compared to healthy controls following test-retest.

CONCLUSIONS

Behavioral therapies may be associated with reduction in substance use and effects on neural systems involved in cognitive control, impulsivity, motivation and attention.

Patterns of cognitive impairments among heroin and cocaine users: the association with self-reported learning disabilities and infectious disease

This study used data from six neuropsychological measures of executive function (EF) and general intellectual functioning (GIF) administered to 303 regular users of heroin and/or cocaine as indicators in a latent profile analysis (LPA). Results indicated the presence of three profiles: impaired GIF and EF profile (30.8%), intact GIF and EF profile (58.8%), and high GIF/intact EF profile (10.4%). Using a multinomial logistic regression, it was determined that individuals who reported being diagnosed with either a learning disability (LD) and/or attention-deficit/hyperactivity disorder (ADHD) were more likely to be in the impaired GIF and EF profile than other profiles. Results from a logistic regression indicated that the impaired GIF and EF profile was associated with a greater prevalence of past hepatitis B and/or C infection. Implication for harm reduction and treatment programs and the need to take into account individuals with LD and ADHD are discussed.

Chronic cocaine exposure induces putamen glutamate and glutamine metabolite abnormalities in squirrel monkeys

RATIONALE

Chronic cocaine exposure has been associated with progressive brain structural and functional changes. Clarifying mechanisms underlying cocaine's progressive brain effects may help in the development of effective cocaine abuse treatments.

OBJECTIVES

We used a controlled squirrel monkey model of chronic cocaine exposure (45 mg/kg/week for 9 months) combined with ultra-high magnetic field (9.4 T) proton magnetic resonance spectroscopy to prospectively measure putamen metabolite changes.

METHODS

Proton metabolites were measured with a STEAM sequence, quantified with LCModel using a simulated basis set, and expressed as metabolite/total creatine (tCr) ratios.

RESULTS

We found cocaine-induced time-dependent changes in putamen glutamate/tCr and glutamine/tCr metabolite ratios suggestive of altered glutamate compartmentalization, neurotransmission, and metabolism. By contrast, saline-treated monkeys exhibited no metabolite changes over time. The time course of cocaine-induced metabolite abnormalities we detected is consistent with the apparent time course of glutamate abnormalities identified in a cross-sectional study in human cocaine users, as well as with microdialysis findings in rodent models of repeated cocaine exposure.

CONCLUSIONS

Together, these findings suggests that this squirrel monkey model may be useful for characterizing glutamatergic changes associated with cocaine exposure and for determining efficacies of treatments designed to mitigate cocaine-induced glutamatergic system dysfunction.

Executive dysfunction in chronic cocaine users: an exploratory study

INTRODUCTION

Chronic cocaine use is associated with some executive deficits. We assessed executive functions using ecologically valid tests in chronic cocaine users.

OBJECTIVES

To investigate the relationship between executive deficits and three measures of severity of cocaine use: years of use, quantity used, and frequency of use.

METHODS

Twenty-four cocaine users were compared with twenty-seven community controls. We used Student's t-test and Chi-squared to compare means and categorical variables, respectively. Linear regression analyses for the adjusted comparative analysis between cases and controls, and severity of cocaine use among cocaine users were performed.

RESULTS

Chronic cocaine users performed worse on measures of attention and working memory (Forward and Backward Digit Span, p<.001), set-shifting abilities (difference score between the Trail Making B and A, TMB-A, p=.006), cognitive test of mental flexibility and response inhibition (Rule Shift Cards) (p<.001), and prefrontal functioning (Wisconsin Card Sorting Test, WCST, p=.023) than controls. Years of cocaine use were associated with deficits in the Backward Digit Span (p=.041; CI 95%: -.760 to -.002), the TMB-A (p=.026; CI 95%: .687 to 9.761), the Zoo Map (p=.034; CI 95%: -.480 to -.021), and the Rule Shift Cards (p=.006; CI 95%: -.836 to -.164), among others. Quantity of cocaine use was associated with executive deficits measured by the Forward Digit Span (p=.007; CI 95%: -.727 to -.133), the TMB-A (p=.021; CI 95%: 5.304-57.945), and the number of perseverative errors in the WSCT (p=.002; CI 95%: -10.654 to -2.800). Frequency of cocaine was associated with deficits in the Backward Digit Span (p=.042; CI 95%: -1.548 to -.030).

CONCLUSIONS

Chronic use of cocaine is associated with executive deficits, which may influence patients' functionality, prognosis, and therapeutic failure.

A pattern of perseveration in cocaine addiction may reveal neurocognitive processes implicit in the Wisconsin Card Sorting Test

The ability to adapt behavior in a changing environment is necessary for humans to achieve their goals and can be measured in the lab with tests of rule-based switching. Disease models, such as cocaine addiction, have revealed that alterations in dopamine interfere with adaptive set switching, culminating in perseveration. We explore perseverative behavior in individuals with cocaine use disorders (CUD) and healthy controls (CON) during performance of the Wisconsin Card Sorting Test (WCST) (N=107 in each group). By examining perseverative errors within each of the 6 blocks of the WCST, we uniquely test two forms of set switching that are differentiated by either the presence (extradimensional set shifting (EDS) - first 3 blocks) or absence (task-set switching - last 3 blocks) of new contingency learning. We also explore relationships between perseveration and select cognitive and drug use factors including verbal learning and memory, trait inhibitory control, motivational state, and urine status for cocaine (in CUD). Results indicate greater impairment for CUD than CON on the WCST, even in higher performing CUD who completed all 6 blocks of the WCST. Block by block analysis conducted on completers' scores indicate a tendency for greater perseveration in CUD than CON but only during the first task-set switch; no such deficits were observed during EDS. This task-set switching impairment was modestly associated with two indices of immediate recall (r=-.32, -.29) and urine status for cocaine [t (134)=2.3, p<.03]. By distinguishing these two forms of switching on the WCST, the current study reveals a neurocognitive context (i.e. initial stage of task-set switching) implicit in the WCST that possibly relies upon intact dopaminergic function, but that is impaired in CUD, as associated with worse recall and possibly withdrawal from cocaine. Future studies should investigate whether dopaminergically innervated pathways alone, or in combination with other monoamines, underlie this implicit neurocognitive processes in the WCST.

Galantamine improves sustained attention in chronic cocaine users

Chronic cocaine users are known to have cognitive deficits that are predictive of poor treatment response. Whether these deficits improve with medications targeting specific cognitive functions has not been examined in previous studies. The goal of this study was to evaluate galantamine's efficacy on selected cognitive outcomes, including measures of sustained attention, response inhibition, and attentional bias in recently abstinent cocaine users. Galantamine, a reversible and competitive inhibitor of acetylcholinesterase, is used clinically in the treatment of Alzheimer's dementia. In a randomized, double-blind, parallel-group study, 34 participants were randomized to galantamine (8 mg/day) or placebo treatment for 10 days. Cognitive and self-report mood measures were obtained at baseline and on Days 5 and 10 after the initiation of treatment. Galantamine treatment, compared to placebo, improved the reaction time, F(2, 50) = 8.6, p < .01, detection sensitivity (A'), F(2, 50) = 4.9, p < .03, number of hits, F(2, 50) = 4.2, p < .04, and number of correct rejections, F(2, 50) = 5.6, p < .02, on the Rapid Visual Information Processing task. With the exception of speeding the reaction time on the Stroop, galantamine did not affect performance on other tasks, (p > .05). These results demonstrate that medications can enhance cognitive function (e.g., sustained attention) in abstinent cocaine users. The potential efficacy of galantamine as a treatment for cocaine abuse needs to be further evaluated in clinical trials.