Distinct cognitive performance and patterns of drug use among early and late onset cocaine users

Attentional ERPs in consumers of smoked and insufflated cocaine associated with neuropsychological performance

BACKGROUND

Cocaine consumption is associated with reduced attentional event-related potentials (ERPs), namely P3a and P3b, indicating bottom-up and top-down deficits respectively. At cognitive level, these impairments are larger for faster routes of administration (e.g., smoked cocaine [SC]) than slower routes (e.g., insufflated cocaine [IC]). Here we assess these ERPs considering the route of cocaine administration. We hypothesized that SC dependent (SCD) would exhibit reduced amplitude of the P3a, while both SCD and IC dependent (ICD) would show reduced amplitude of the P3b.

METHODS

We examined 25 SCD, 22 ICD matched by poly-consumption profiles, and 25 controls matched by demographic variables. We combined EEG data from the Global-Local task with behavioral data from attentional cognitive tasks.

RESULTS

At the behavioral level, SCD exhibited attentional deficits in both bottom-up and top-down processes, while ICD only showed a tendency for top-down deficits. The amplitude of P3a and P3b was lower in Users groups. We observed subtle route-based differences, with larger differences in the P3a for SCD and in the P3b for ICD. Neurophysiological and behavioral data converged, with the P3a associated to bottom-up performance and P3b to top-down.

CONCLUSIONS

Different routes of administration lead to distinct attentional neurocognitive profiles. Specifically, SCD showed greater attentional impairment, mainly at bottom-up/P3a, while ICD showed a trend of top-down/P3b deficits. These findings emphasize the crucial role of considering the route of administration in both clinical and research settings and support the use of attentional ERPs as valid measures for assessing attentional deficits in substance Dependence.

Recency memory is altered in cocaine-withdrawn adolescent rats: Implication of cortical mTOR signaling

In humans, cocaine abuse during adolescence poses a significant risk for developing cognitive deficits later in life. Among the regions responsible for cognitive processes, the medial prefrontal cortex (mPFC) modulates temporal order information via mechanisms involving the mammalian-target of rapamycin (mTOR)-mediated pathway and protein synthesis regulation. Accordingly, our goal was to study the effect of repeated cocaine exposure during both adolescence and adulthood on temporal memory by studying the mTOR pathway in the mPFC. Adolescent or adult rats underwent repeated cocaine injections for 15 days and, after two weeks of withdrawal, engaged in the temporal order object recognition (TOOR) test. We found that repeated cocaine exposure during adolescence impaired TOOR performance, while control or adult-treated animals showed no impairments. Moreover, activation of the mTOR-S6-eEF2 pathway following the TOOR test was diminished only in the adolescent cocaine-treated group. Notably, inhibition of the mTOR-mediated pathway by rapamycin injection impaired TOOR performance in naïve adolescent and adult animals, revealing this pathway to be a critical component in regulating recency memory. Our data indicate that withdrawal from cocaine exposure impairs recency memory via the dysregulation of protein translation mechanisms, but only when cocaine is administered during adolescence.

Cognitive Alterations in Addictive Disorders: A Translational Approach

The cognitive decline in people with substance use disorders is well known and can be found during both the dependence and drug abstinence phases. At the clinical level, cognitive decline impairs the response to addiction treatment and increases dropout rates. It can be irreversible, even after the end of drug abuse consumption. Improving our understanding of the molecular and cellular alterations associated with cognitive decline could be essential to developing specific therapeutic strategies for its treatment. Developing animal models to simulate drug abuse-induced learning and memory alterations is critical to continue exploring this clinical situation. The main aim of this review is to summarize the most recent evidence on cognitive impairment and the associated biological markers in patients addicted to some of the most consumed drugs of abuse and in animal models simulating this clinical situation. The available information suggests the need to develop more studies to further explore the molecular alterations associated with cognitive impairment, with the ultimate goal of developing new potential therapeutic strategies.

Impaired cognitive control moderates the relation between the attribution of incentive salience and severity of consumption in patients with methamphetamine dependence

BACKGROUND

Cognitive control and the attribution of incentive salience are two key neuropsychological processes proposed to explain substance use disorder (SUD). However, little is known about how they interact to influence the severity of drug use in people with SUD.

OBJECTIVE

To determine if cognitive control exerts a moderating effect on the relation between the attribution of salience to drug/reward-related cues and the severity of drug use in SUD cases.

METHOD

Sixty-nine SUD cases with methamphetamine as the main drug of consumption were selected and evaluated. Participants performed the Stroop, Go/No-Go, and Flanker tasks to identify a latent cognitive control factor, and the Effort-Expenditure for Reward task, as well as answering the Methamphetamine Incentive Salience Questionnaire to measure the attribution of incentive salience. Severity of drug use was determined by the KMSK scale and an exploratory clinical interview.

RESULTS

As expected, higher incentive salience attribution predicted greater severity of methamphetamine use. Unexpectedly, however, we found a moderating effect of impaired cognitive control on the relations between higher incentive salience scores and higher monthly drug use, and between younger age at onset of systematic drug use and higher incentive salience scores.

CONCLUSION

Results show the moderating role of cognitive control on the relation between incentive salience attribution and severity of drug use in SUD cases, and help explain the chronic, relapsing nature of addiction, knowledge necessary to develop more precise prevention and treatment strategies.

Cocaine use disorder is associated with widespread surface-based alterations of the basal ganglia

Cocaine use is a major public health problem with significant negative consequences at the individual and societal levels. Cocaine use disorder (CUD) is closely associated with brain structure alterations, which are mainly analyzed using voxel-based morphometric and traditional volumetric methods with certain limitations. This study conducted vertex-wise shape analysis to examine the effects of cocaine use on surface-based alterations of the basal ganglia in CUD. A total of 68 CUD individuals and 52 matched healthy controls (HCs) were enrolled in the study and underwent MRI scans and clinical measures. There were no significant differences in the volume of brain tissues and subcortical structures between groups. Related to HCs, CUD individuals showed regional surface atrophy of the left medial anterior thalamus, right medial posterior thalamus, and right dorsal anterior caudate, which were found to exhibit more significant surface atrophy in CUD individuals with onset age of cocaine use below 18. Furthermore, surface-based alteration of the right dorsal anterior caudate was significantly associated with years of cocaine use and the onset age of cocaine use in CUD individuals. Furthermore, both CUD individuals with onset age of cocaine use below 18 and CUD individuals with onset age of cocaine use above 18 showed similar significant relationship patterns between regional surface alteration of right dorsal anterior caudate and the onset age of cocaine use. These findings shed light on the effect of cocaine use on basal ganglia, help us understand the neural basis of cocaine dependence, and further provide effective interventions for CUD.

A randomized, double-blind, placebo-controlled trial of ondansetron for the treatment of cocaine use disorder with post hoc pharmacogenetic analysis

BACKGROUND

Cocaine use disorder (CUD) has significant consequences and there remain no FDA-approved pharmacotherapies. Ondansetron is an indirect dopaminergic modulator that has shown efficacy in alcohol use disorder, particularly in phenotypic and genotypic subgroups, and was found to be efficacious in a pilot dose-finding trial for CUD.

METHODS

One-hundred eight (108) adults with CUD were randomized to ondansetron 4 mg twice daily or placebo for 9 weeks and assessed up to thrice weekly to evaluate self-reported cocaine use and urine benzoylecgonine. Participants received cognitive-behavioral therapy and brief behavioral compliance enhancement therapy. Consenting participants (N = 79) provided blood samples for exploratory pharmacogenetic analyses.

RESULTS

Participants in both arms reduced cocaine use over time, but there was no statistically significant difference on percentage of cocaine-free days (PCFD; p = 0.972) or percentage of cocaine-free urine samples (PCFU; p = 0.909). Participants with early-onset CUD had greater improvement regardless of study arm (p = 0.002). Post hoc pharmacogenetic analyses demonstrated an interaction effect between treatment and rs1176713 SNP on PCFU in the total sample (p = 0.040) and African ancestry subset (p = 0.03). Constipation, fatigue, and somnolence were more common among ondansetron-treated participants (Fisher exact p < 0.05). Those who developed constipation were mostly rs1176713:GG carriers (Fisher exact p = 0.029).

CONCLUSIONS

Ondansetron did not demonstrate efficacy in the treatment of CUD. However, these preliminary results suggest a genotype-based variance in response to ondansetron in African ancestry individuals with CUD. Further studies are needed to validate findings for developing a personalized genomic approach for CUD treatment in racially and ethnically diverse populations.

Early onset consumption of coca paste associated with executive-attention vulnerability markers linked to caudate-frontal structural and functional abnormalities

Coca paste is the most popular form of smoked cocaine (SC) in Latin America and also the most widespread among adolescents in vulnerable sectors of society, thus representing a significant public health concern. Despite evidence suggesting that abnormal executive-attention function is predictive of addiction to stimulant drugs, no study to date has compared clinically relevant neuropsychological (NPS) and physiological variables between individuals with histories of smoked cocaine dependence (SCD) and insufflated cocaine hydrochloride dependence (ICD). In this study we evaluated 25 SCD and 22 ICD subjects matched by poly-consumption profiles, and 25 healthy controls (CTR) matched by age, gender, education, and socioeconomic status. An exhaustive NPS battery was used to assess cognitive domains (attention, executive functions, fluid intelligence, memory, language and social cognition). We complemented this assessment with structural (MRI) and functional (fMRI) neuroimaging data. We found that executive function and attention impairments could be explained by the administration route of cocaine, with strongest impairments for the SCD group. SCD also presented reduced grey matter density relative to ICD and CTR in the bilateral caudate, a key area for executive and attentional function. Functional connectivity between left caudate and inferior frontal regions mediated the association between brain structure and behavioral performance. Our results highlight the relevance of assessing the route of administration of stimulants, both in clinical and research settings.

Web-Based Cognitive Training to Improve Working Memory in Persons with Co-Occurring HIV Infection and Cocaine Use Disorder: Outcomes from a Randomized Controlled Trial

Neurocognitive impairment (NCI) remains a persistent complication of HIV disease that nearly half of persons with HIV experience, and rates are even higher in persons who use substances such as cocaine. Cognitive training is a promising intervention for HIV-associated NCI. In this randomized controlled trial, we examined the feasibility and effectiveness of a web-based cognitive training program to improve working memory in a sample of 58 persons with HIV and cocaine use disorder. Participants were randomly assigned to either the experimental working memory training arm or the attention control training arm and completed up to 48 daily sessions over 10 weeks. Overall, treatment completion (74%) and retention rates (97%) were high, and participant feedback indicated the intervention was acceptable. Our results show that the intervention successfully reduced working memory deficits in the experimental arm relative to the control arm. Our findings support both the feasibility and effectiveness of cognitive training in this population.

Factors Predicting Detrimental Change in Declarative Memory Among Women With HIV: A Study of Heterogeneity in Cognition

Objective

Statistical techniques used to study cognitive function in HIV typically yield normative estimates and can mask the heterogeneity in cognitive trajectories over time. We applied a novel statistical approach to identify clusters of individuals with distinct patterns of change in declarative memory in HIV-seropositive (HIV+) and HIV-seronegative (HIV−) women.

Methods

1731 women from the Women’s Interagency HIV Study, a multi-center, prospective cohort study, completed the Hopkins Verbal Learning Test-Revised (HLVT-R) at >2 visits. To derive subgroups with similar patterns of decline by HIV-serostatus, we used a mixed-effects framework that modeled the trajectory of multiple declarative memory outcomes over time, while simultaneously clustering individuals.

Results

Of the 1731 participants, 1149 were HIV+ (70% Black/African American [AA]; 30% White/Other [W/O]) and 582 were HIV− (68% AA; 32% W/O). Race stratification was necessary to optimize clustering. Among HIV+AA’s, four subgroups emerged: a subgroup with minimal decline, two with accelerated decline, and one with stable but low performance. In HIV− AA, three subgroups emerged: one with minimal decline and two with accelerated decline. In multivariable-adjusted models among HIV+, individuals with accelerated decline were less educated (P < 0.001) and more likely to have a history of depression (P < 0.001) versus those with minimal decline. Similar subgroups were identified in W/O HIV+ and W/O HIV− participants.

Conclusion

We identified clinically meaningful subgroups of women with distinct phenotypes of declarative memory decline, which depend on race and HIV-serostatus using a data driven approach. Identification of underlying mechanisms and risk factors contributing to the observed differences are warranted. More broadly our modeling approach could be other populations to identify risk factors for accelerated cognitive decline and to personalize interventions.

Extended access self-administration of methamphetamine is associated with age- and sex-dependent differences in drug taking behavior and recognition memory in rats

Individuals who begin drug use during early adolescence experience more adverse consequences compared to those initiating later, especially if they are female. The mechanisms for these age and gender differences remain obscure, but studies in rodents suggest that psychostimulants may disrupt the normal ontogeny of dopamine and glutamate systems in the prefrontal cortex (PFC). Here, we studied Sprague-Dawley rats of both sexes who began methamphetamine (METH, i.v.) self-administration in adolescence (postnatal [P] day 41) or adulthood (P91). Rats received seven daily 2-h self-administration sessions with METH or saccharin as the reinforcer, followed by 14 daily long access (LgA; 6 h) sessions. After 7 and 14 days of abstinence, novel object (NOR) or object-in-place (OiP) recognition was assessed. PFC and nucleus accumbens were collected 7 days after the final cognitive test and NMDA receptor subunits and dopamine D1 receptor expression was measured. We found that during LgA sessions, adolescent-onset rats escalated METH intake more rapidly than adult-onset rats, with adolescent-onset females earning the most infusions. Adolescent-onset rats with a history of METH self-administration exhibited modest deficits in OiP compared to their adult-onset counterparts, but there was no sex difference and self-administration groups did not differ from naïve control rats. All rats displayed intact novel object recognition memory. We found no group differences in D1 and NMDA receptor expression, suggesting no long-lasting alteration of ontogenetic expression profiles. Our findings suggest that adolescent-onset drug use is more likely to lead to compulsive-like patterns of drug-taking and modest dysfunction in PFC-dependent cognition.

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.

An examination of the association between early initiation of substance use and interrelated multilevel risk and protective factors among adolescents

One of the major goals of drug use prevention programs is to delay the age of onset of substance use. What is called early initiation, usually occurring in adolescents under the age of 15, is a salient predictor of Substance Use Disorders later in adulthood. The causes of early initiation are complex and multifaceted and this has led to the identification of a rich set of risk and protective factors that influence age of onset. Nonetheless, there is little knowledge about the interdependence of these factors in their impact on early initiation. This paper addresses this question by applying Multiple Correspondence Analysis to data on family, community and social risk and protective factors from over 1200 adolescents. We find that community and to a lesser extent social factors are the most clearly associated to early initiation and we compare our results to those obtained from linear regression analyses of the same data that do not incorporate interdependence and find opposite results. We discuss the differences between linear regressions and MCA to evaluate the interplay of risk and protective factors and the implications of our findings for health policy and the design of prevention interventions aimed at delaying age of onset.

Distinct effects of cocaine and cocaine + cannabis on neurocognitive functioning and abstinence: A six-month follow-up study

BACKGROUND AND AIMS

Cannabis use is frequent among individuals with cocaine use disorder. Despite recent non-controlled studies advocating a therapeutic role of smoked cannabis, there is a paucity of evidence-based data on potential therapeutic and cognitive side-effects of this association.

METHODS

We examined 63 cocaine-addicted subjects who used cannabis more than 50 times in lifetime (COC + CAN), 24 cocaine-addicted patients who use cannabis less than 50 times (COC), and 36 controls (CON). Participants were evaluated with an extensive battery of neurocognitive tests after two weeks of supervised detoxification in an inpatient treatment program. Patients were followed up in one, three, and six months after discharge.

RESULTS

Both groups of patients performed worse than CON on working memory, processing speed, inhibitory control, mental flexibility, and decision making. COC + CAN performed worse than COC on speed processing, inhibitory control and sustained attention, while COC performed worse than COC + CAN on mental flexibility. Concomitant cannabis use did not decrease relapses to cocaine use after one, three and six months. Among COC + CAN, earlier cocaine and cannabis use, and impaired executive functioning were predictive of relapse on cocaine after six months.

CONCLUSION

Our results did not support the recommendation of smoked cannabis as a safe therapeutic approach for cocaine-addicted patients due to significant negative cognitive side-effects and absence of efficacy. Further studies investigating frontal brain morphology, neuromaturation, and prescription of the non-psychoactive constituent of cannabis sativa cannabidiol among cocaine-addicted patients who use cannabis are warranted.

The role of neurocognitive functioning, substance use variables and the DSM-5 severity scale in cocaine relapse: A prospective study

BACKGROUND

The severity of substance use disorder (SUD) is currently defined by the sum of DSM-5 criteria. However, little is known about the validity of this framework or the role of additional severity indicators in relapse prediction. This study aimed to investigate the relationship between DSM-5 criteria, neurocognitive functioning, substance use variables and cocaine relapse among inpatients with cocaine use disorder (CUD).

METHODS

128 adults aged between 18 and 45 years were evaluated; 68 (59 males, 9 females) had CUD and 60 (52 males, 8 females) were healthy controls. For the group with CUD, the use of other substances was not an exclusion criterion. Participants were tested using a battery of neurocognitive tests. Cocaine relapse was evaluated 3 months after discharge.

RESULTS

Scores for attention span and working memory were worse in patients compared to controls. Earlier onset and duration of cocaine use were related to poorer inhibitory control and global executive functioning, respectively; recent use was related to worse performance in inhibitory control, attention span and working memory. More DSM-5 criteria at baseline were significantly associated with relapse.

CONCLUSIONS

Recent cocaine use was the most predictive variable for neurocognitive impairments, while DSM-5 criteria predicted cocaine relapse at three months post treatment. The integration of neurocognitive measures, DSM-5 criteria and cocaine use variables in CUD diagnosis could improve severity differentiation. Longitudinal studies using additional biomarkers are needed to disentangle the different roles of severity indicators in relapse prediction and to achieve more individualized and effective treatment strategies for these patients.

Remittance or persistence of attention deficit-hyperactivity disorder (ADHD) and its impact on recidivism in risky driving behaviors

OBJECTIVE

Recent data regarding the persistence or remittance of attention deficit-hyperactivity disorder (ADHD) diagnosis into adulthood raise the question of its possible role in crucial public health issues, including road safety, especially when neurocognitive capacities are challenged.

METHODS

The study included 611 participants with serious traffic violations. The Spanish version of the Mini International Neuropsychiatric Interview (M.I.N.I.) was used to assess psychopathology. They were grouped into 3 diagnostic conditions: non-ADHD, persistent ADHD (ADHD-P), and remittent ADHD (ADHD-R). Several risky driving behaviors were analyzed.

RESULTS

Although participants with ADHD have more driving violations relative to non-ADHD, ADHD-R, and ADHD-P drivers have similar profiles. ADHD-R and ADHD-P drivers are more prone to perform risky and recidivistic behaviors relative to non-ADHD counterparts (P = .044 and P = .047, respectively); ADHD-R and ADHD-P participants are statistically comparable in this proneness (P = .772).

CONCLUSION

These results suggest that the underlying core deficits of ADHD-attention and other executive disabilities-persist despite the fact that some people no longer reach the threshold for clinical diagnosis.

The Role of Working Memory for Cognitive Control in Anorexia Nervosa versus Substance Use Disorder

Prefrontal cortex executive functions, such as working memory (WM) interact with limbic processes to foster impulse control. Such an interaction is referred to in a growing body of publications by terms such as cognitive control, cognitive inhibition, affect regulation, self-regulation, top-down control, and cognitive–emotion interaction. The rising trend of research into cognitive control of impulsivity, using various related terms reflects the importance of research into impulse control, as failure to employ cognitions optimally may eventually result in mental disorder. Against this background, we take a novel approach using an impulse control spectrum model – where anorexia nervosa (AN) and substance use disorder (SUD) are at opposite extremes – to examine the role of WM for cognitive control. With this aim, we first summarize WM processes in the healthy brain in order to frame a systematic review of the neuropsychological, neural and genetic findings of AN and SUD. In our systematic review of WM/cognitive control, we found n = 15 studies of AN with a total of n = 582 AN and n = 365 HC participants; and n = 93 studies of SUD with n = 9106 SUD and n = 3028 HC participants. In particular, we consider how WM load/capacity may support the neural process of excessive epistemic foraging (cognitive sampling of the environment to test predictions about the world) in AN that reduces distraction from salient stimuli. We also consider the link between WM and cognitive control in people with SUD who are prone to ‘jumping to conclusions’ and reduced epistemic foraging. Finally, in light of our review, we consider WM training as a novel research tool and an adjunct to enhance treatment that improves cognitive control of impulsivity.