Differences in impulsivity and sexual risk behavior among inner-city crack/cocaine users and heroin users

The current study utilized a sample of 123 inner-city drug users in residential treatment, comparing sexual risk behavior (SRB) across primary users of (a) heroin and not crack/cocaine, (b) crack/cocaine and not heroin, and (c) both heroin and crack/cocaine. Additional analyses also examined impulsivity as a mediator of drug choice and SRB. Results indicated that SRB was higher in primary crack/cocaine users than in primary heroin users, with those using both drugs evidencing intermediate levels of SRB. Beyond differences in SRB, a similar pattern across drugs was found for impulsivity. Finally, impulsivity mediated the relationship between drug choice and SRB. Although further research is necessary to establish causal relationships, these results support a relationship between SBR and crack/cocaine, and suggest that disinhibition processes including impulsivity may underlie this relationship.     

Differences between methamphetamine users and cocaine users in treatment

To better understand the distinguishing characteristics of methamphetamine users versus cocaine users, we conducted a retrospective chart review of the 345 patients admitted to an outpatient stimulant treatment program during 1995--1997. Analyses revealed an increase in methamphetamine patients over the 3-year period, and that these patients were more likely than cocaine patients to be male, Caucasian, and gay or bisexual. Methamphetamine patients were also more likely to be HIV-positive, engage in behaviors such as using and sharing needles that place them at high risk for HIV transmission, have a psychiatric diagnosis, and be on psychiatric medications. The two populations did not differ in treatment adherence, as measured by clinic attendance, drug-free urines, and successful completion of treatment. These findings suggest that highly specialized substance abuse treatments for methamphetamine patients may not be needed. Resources may be directed toward addressing their medical and psychiatric diagnostic issues by providing ancillary services to stimulant treatment programs.     

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

Background

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

Methods

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

Results

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

Conclusions

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

Cognitive impulsivity in cocaine and heroin polysubstance abusers

RATIONALE: Chronic abuse of psychoactive substances produces significant deficits in executive control functions (ECF). These deficits are prominent in different domains associated with cognitive impulsivity, including response inhibition and decision-making. The extent and nature of these deficits may depend on the principal substance of abuse. OBJECTIVES: To analyse response inhibition and decision-making performance in abstinent polysubstance abusers (PSA) of cocaine and heroin, and healthy participants. METHODS: We used univariate and multivariate analyses of variance to compare the performances of cocaine and heroin PSA and healthy controls on several well-validated measures of response inhibition (Stroop, 5-Digit Test and Go/No Go Task) and decision-making (Iowa Gambling Task). Post-hoc exploratory analyses of the results from the Go/No Go task were conducted to examine specific effects of task switching on the pattern of omission/commission errors in the PSA groups. RESULTS: Cocaine but not heroin PSA showed significant deficits on several measures of response inhibition, when compared to controls. Reversal of task contingencies in the Go/No Go task primarily altered the commission error rate in cocaine PSA, and the omission error rate in heroin PSA. In contrast, both cocaine and heroin PSA showed poorer performance on decision-making compared to controls. CONCLUSIONS: Assuming the relevance of polysubstance involvement, cocaine abuse seems to differentially correlate with motor impulsivity skills, while both substances seem to be equally linked to the inability to decide advantageously in complex decision-making tasks. Possible discrepancies in the neurological and psychological effects of these drugs are discussed.     

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

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

Differences between adult non-drug users versus alcohol,cocaine and concurrent alcohol and cocaine problem users

Concurrent drug use is a serious public health concern with significant morbidity and mortality associated with the combined use of alcohol and cocaine. Multinomial logistic regression was used to assess differences between non-drug users and alcohol, cocaine and concurrent problem users incorporating data from the 2005 National Survey on Drug Use and Health. Results demonstrated that alcohol and cocaine use is associated with mental health disturbance, other drug use and adverse social consequences. Furthermore, concurrent users were more likely to report cigarette and marijuana use as well as lifetime STDs and arrest for breaking the law. Study results have implications for planning prevention and treatment services differentially for alcohol, cocaine and concurrent users and support the need for more intense resources allocated to the prevention and treatment of the concurrent use of alcohol and cocaine.     

Predictors of heroin abstinence in opiate substitution therapy in heroin-only users and dual users of heroin and crack

AimsTo analyse predictors of heroin abstinence in opiate substitution therapy (OST) based on frequency of crack use and its interactions with other predictors in a clinical non-experimental setting.DesignRetrospective study.SettingA community drug service in London, UK.Participants325 clients starting OST between 2010 and 2014 (197 methadone and 128 buprenorphine).MeasurementsLogistic regression models (a general model and separate models for methadone and buprenorphine) assessed demographic and clinical data as predictors of heroin abstinence at one year after treatment start (or at the date of transfer to another service).FindingsFor the general model participants choosing methadone were more likely to use heroin at follow up (OR = 2.36, 95% CI: 1.40–3.17) as were daily crack users on methadone (OR = 2.62, 95% CI: 0.96–7.16).For the methadone model only daily crack use predicted heroin use at follow up (OR = 2.62, 95% CI: 0.96–7.16).For buprenorphine, higher amounts of baseline heroin use, lower buprenorphine dose and daily drinking predicted heroin use at follow up (OR = 0.85, 95% CI: 0.75–0.95; OR = 1.31, 95% CI: 1.06–1.60 and OR = 6.04, 95% CI: 1.26–28.92). Both use of cannabis and depression increased likelihood of heroin abstinence for clients not using crack compared to occasional (OR = 6.68, 95% CI: 0.37–119.59; OR = 106.31, 95% CI: 3.41–3313.30) and daily (OR = 57.49 (95% CI: 2.37–1396.46; OR = 170.99 (95% CI: 4.61–6339.47) users.ConclusionsMost of the predictors in the general model were found significant only in the buprenorphine but not in the methadone model, suggesting that a general model has little predictive value. Crack use was a significant predictor of heroin abstinence at follow up in all models, however for buprenorphine only when depression or cannabis use was present. Further research is needed to assess effective treatment approaches for the growing population of dual users.     

A comparison of motivations for use among users of crack cocaine and cocaine powder in a sample of simultaneous cocaine and alcohol users

This study examined the motivations for using cocaine and alcohol comparing those who primarily smoked crack and those who primarily used cocaine powder when using simultaneously with alcohol. Motivations examined included: 1) to cope with a negative affect, 2) enhancement, 3) to be social and 4) to conform. The research design was a cross-sectional study in which clients in treatment for cocaine and alcohol problems completed a self-administered questionnaire about their substance use. Among those who primarily smoked crack or snorted cocaine when also using alcohol (n = 153), there were 93 participants who reported primarily snorting cocaine and 60 participants who primarily reported smoking crack. Bivariate analyses found that those who primarily smoked crack reported lower social motivations to use alcohol and cocaine. When adjusting for other covariates in a multivariate analysis, social motivation was still significantly different between groups. Additionally, those who primarily smoked crack were more likely to be older, report higher cocaine dependence severity, be unemployed and were less likely to have completed some post-secondary education, than those who primarily snorted cocaine. No differences were found in enhancement, coping or conformity motivations between the two groups. These results suggest that simultaneous cocaine and alcohol use may have social importance to those who primarily snort cocaine, but that this importance is less evident to those who smoke crack. Consequently, future studies examining motivations for simultaneous cocaine and alcohol use should distinguish between different routes of cocaine administration.     

Differences in orbitofrontal activation during decision-making between methadone-maintained opiate users, heroin users and healthy volunteers

Objective Previously, we reported that opiate users enrolled in methadone treatment made ‘risky’ choices on a decision-making task following a loss of points compared with heroin users and healthy volunteers. One possible explanation for this behaviour is that methadone users were less sensitive to punishment on immediately preceding unsuccessful trials.Methods We sought to explore this finding from a neural perspective by performing a post hoc analysis of data from a previous positron emission tomography study. We restricted the analysis to the opiate groups and controls, assessing differences between opiate users on methadone and those on heroin.Results We found significant over-activation in the lateral orbitofrontal cortex (OFC) in methadone users compared with both heroin users and controls concomitant with the greatest overall tendency to ‘play risky’. Heroin users showed significant under-activation in this area compared with the other two groups whilst exhibiting the greatest overall tendency to ‘play safe’. Correlational analysis revealed that abnormal task-related activation of the left OFC was associated with the dose of methadone in methadone users and with the duration of intravenous heroin use in heroin users. ‘Playing safe’ following a loss of points was also negatively correlated with the activation of pregenual anterior cingulate and insula cortex in controls, but not in opiate users.Conclusion Our findings suggest that the interplay between processes involved in integrating penalty information for the purpose of response selection may be altered in opiate users. This change was reflected differentially in task-related pattern of OFC activation depending on the opiate used.     

Incidence of psychopathology in a cohort of young heroin and/or cocaine users

A prospective study was carried out in Barcelona, Spain, to determine the incidence of mental disorders including substance use disorders (SUDs). From a cohort of 288 young adult (aged 18-30 years) cocaine and/or heroin users recruited in nonclinical settings, 158 were reinterviewed 18 months later using the Psychiatric Research Interview for Substance and Mental Disorders. During follow-up, 18% of subjects presented a new SUD, and nearly 11% a new non-SUD Axis I disorder. Incidence was highest for mood disorders (8%). Being a woman, a lower frequency of substance use at baseline, a younger age of heroin first use, and a worsening of SUD were associated with a higher likelihood of presenting a new Axis I disorder. Having received drug treatment ever (at baseline) or during follow-up was not associated with progress of SUD. An overall improvement in the psychiatric status of these young substance users was observed.     

Novelty seeking as a predictor of treatment retention for heroin dependent cocaine users

This study examined the relationship between novelty seeking between treatment retention and among heroin dependent cocaine users. Participants were treated with buprenorphine maintenance and contingency management. The Tridimensional Personality Questionnaire's (TPQ) Novelty Seeking scale was administered to 68 participants prior to buprenorphine induction. Demographics, mood and anxiety disorders, antisocial personality disorder, and substance use were also assessed. Variables with significant relationships with overall retention were entered into a logistic regression analysis. In addition, using a survival analysis, all variables with significant relationships with time to drop-out were entered into a multivariate proportional hazards regression with time dependent covariates. Results demonstrated that although high novelty seekers, in comparison to low novelty seekers, were more likely to drop-out by the end of treatment, they had higher retention rates during the early phases of treatment. It is suggested that buprenorphine and contingency management were viewed by participants as novel treatment components and thus facilitated high novelty seekers' success early in treatment. If replicated, results suggest that inclusion of novel treatment components might facilitate retention among this at-risk group.     

Polydrug use and its association with drug treatment outcomes among primary heroin,methamphetamine, and cocaine users

BackgroundPolydrug use may challenge effective treatment for substance use disorders. We evaluate whether secondary substance use modifies the association between treatment and primary drug use among primary heroin, cocaine and methamphetamine (MA) users.MethodsData were obtained from prospective cohort studies on people who use illicit drugs (PWUD) in California, USA. Using repeated monthly data on self-reported secondary substance use (heroin, cocaine, MA, alcohol or marijuana; ≥1 day in a month), primary drug use (≥1 day in a month), and treatment participation, collected via timeline follow-back, we fitted generalized linear mixed multiple regression models controlling for potential confounders to examine the interactions between treatment and secondary substance use on the odds of primary heroin, cocaine and MA use, respectively.ResultsIncluded in our study were 587 primary heroin, 444 primary MA, and 501 primary cocaine users, with a median of 32.4, 13.3 and 18.9 years of follow-up, respectively. In the absence of secondary substance use, treatment was strongly associated with decreased odds of primary drug use (adjusted odds ratios (aORs): 0.25, 95% CI: 0.24, 0.27, 0.07 (0.06, 0.08), and 0.07 (0.07, 0.09)) for primary heroin, MA, and cocaine users, respectively. Secondary substance use of any kind moderated these associations (0.82 (0.78, 0.87), 0.25 (0.21, 0.30) and 0.53 (0.45, 0.61), respectively), and these findings were consistent for each type of secondary substance considered. Moreover, we observed different associations in terms of direction and magnitude between secondary substance use and primary drug use during off-treatment periods across substance types.ConclusionThis study demonstrates secondary substance use moderates the temporal associations between treatment and primary drug use among primary heroin, MA and cocaine users. Disparate patterns of polydrug use require careful measurement and analysis to inform targeted treatment for polydrug users.     

Age and HIV risk in a national sample of injection drug and crack cocaine users

A national sample of 25,106 out-of-treatment crack cocaine and injection drug users was examined to determine the effect of aging on HIV risk behavior. Injectors and crack cocaine users aged 55 and over were compared to those who were aged 18 to 54 years of age. Results showed that the behavior risk of older persons did not differ substantially from those reported by other age groups, and that injection risk rose steadily along with age for all ages represented in the sample. The authors conclude that older persons who use illegal drugs remain at elevated risk for HIV compared to the general population, and may be in need of more targeted intervention strategies.     

Voucher reinforcement for heroin and cocaine abstinence in an outpatient drug-free program

This study examined an abstinence-contingent voucher incentive program in opiate-dependent clients enrolled in outpatient drug-free (nonmethadone) treatment. Study participants were referred from local detoxification programs and randomly assigned to voucher (n = 29) or no-voucher (n = 23) conditions. Both groups received intensive cognitive-behavioral counseling; those in the voucher condition could earn up to $1,087.50 over 3 months for submitting urines negative for both opiates and cocaine. Voucher versus no-voucher groups did not differ significantly on mean days retained in treatment (35.9 vs. 39.3 days), mean number of opiate- and cocaine-negative urines submitted (8.3 vs. 6.2), longest duration of continuous abstinence (16.8 vs. 12.1 days), or percentage of participants abstinent for 4 weeks (20.7% voucher vs. 9% no voucher). Possible reasons for negative findings are discussed. Findings suggest that voucher programs must be better tailored to the clinical population and behavioral targets being addressed.     

History of regular nonmedical sedative and/or alcohol use differentiates substance-use patterns and consequences among chronic heroin users

BackgroundConcurrent use of sedating substances (e.g. alcohol or benzodiazepines) with opioids is associated with increased negative consequences of opioid use; however, few studies have attempted to differentiate effects of using sedating substances on heroin-use outcomes. This study examines differences between heroin users who use alcohol or misuse sedatives regularly and those who do not.MethodsSubstance-use data were collected from 367 non-treatment seeking, chronic heroin-using, 18-to-55 year-old participants. We created 4 groups based on self-reported lifetime history of regular (at least weekly) substance use: heroin only (n = 95), heroin and sedatives (n = 21), heroin and alcohol (n = 151), and heroin, sedative, and alcohol (n = 100). Chi-square analyses and ANOVAs with Bonferroni post hoc tests were used to explore differences between these groups.ResultsHeroin users who denied lifetime alcohol or nonmedical sedative use regularly endorsed fewer consequences associated with any substance they had used. Total adverse consequences of heroin use (e.g. health problems) were significantly higher among those who misused sedatives regularly, irrespective of alcohol use history (F(3,361) = 10.21; p < .001). Regular alcohol use did not independently impact heroin consequences but was associated with increased use of other substances.ConclusionsAlthough polysubstance use is normative among heroin users, the risks depend on the substances used. Regular sedative use is associated with increased heroin consequences whereas regular alcohol use is not. This study refines the investigation of polysubstance use and highlights subgroup differences depending on types of substances used regularly. This knowledge is critical for understanding substance-use motivations and creating avenues for harm reduction.     

Prevalence of executive dysfunction in cocaine, heroin and alcohol users enrolled in therapeutic communities

Many studies have observed relevant executive alterations in polysubstance users but no data have been generated in terms of prevalence of these alterations. Studies of the prevalence of neuropsychological impairment can be useful in the design and implementations of interventional programs for substance abusers. The present study was conducted to estimate the prevalence of neuropsychological impairment in different components of executive functions in polysubstance users enrolled in therapeutic communities. Moreover, we estimated the effect size of the differences in the executive performance between polysubstance users and non substance users in order to know which neuropsychological tasks can be useful to detect alterations in the executive functions. Study results showed a high prevalence of executive function impairment in polysubstance users. Working memory was the component with the highest impairment proportion, followed by fluency, shifting, planning, multi-tasking and interference. Comparisons between user groups showed very similar executive impairment prevalence for all the analyzed executive components. The best discriminating task between users and controls was Arithmetic (Wechsler Adult Intelligence Scale, WAIS-III). Moreover FAS and Ruff Figural Fluency Test was discriminating for fluency, Category Test for shifting, Stroop Colour-Word Interference Test for interference, Zoo Map (Behavioural Assessment of the Dysexecutive Syndrome, BADS) for planning and Six Elements (BADS) for multi-tasking. The existence of significant prevalence of executive impairment in polysubstance users reveals the need to redirect the actuation policies in the field of drug-dependency towards the creation of treatments addressed at the executive deficits of the participants, which in turn would facilitate the individuals' compliance and final rehabilitation.     

Differential associations between impulsivity and risk-taking and brain activations underlying working memory in adolescents

Increased impulsivity and risk-taking are common during adolescence and relate importantly to addictive behaviors. However, the extent to which impulsivity and risk-taking relate to brain activations that mediate cognitive processing is not well understood. Here we examined the relationships between impulsivity and risk-taking and the neural correlates of working memory. Neural activity was measured in 18 adolescents (13–18 years) while they engaged in a working memory task that included verbal and visuospatial components that each involved encoding, rehearsal and recognition stages. Risk-taking and impulsivity were assessed using the Balloon Analogue Risk Task (BART) and the adolescent version of the Barratt Impulsiveness Scale—11 (BIS-11A), respectively. We found overlapping as well as distinct regions subserving the different stages of verbal and visuospatial working memory. In terms of risk-taking, we found a positive correlation between BART scores and activity in subcortical regions (e.g., thalamus, dorsal striatum) recruited during verbal rehearsal, and an inverse correlation between BART scores and cortical regions (e.g., parietal and temporal regions) recruited during visuospatial rehearsal. The BIS-11A evidenced that motor impulsivity was associated with activity in regions recruited during all stages of working memory, while attention and non-planning impulsivity was only associated with activity in regions recruited during recognition. In considering working memory, impulsivity and risk-taking together, both impulsivity and risk-taking were associated with activity in regions recruited during rehearsal; however, during verbal rehearsal, differential correlations were found. Specifically, positive correlations were found between: (1) risk-taking and activity in subcortical regions, including the thalamus and dorsal striatum; and, (2) motor impulsivity and activity in the left inferior frontal gyrus, insula, and dorsolateral prefrontal cortex. Therefore these findings suggest that while there may be some overlap in the neural correlates of working memory and their relationship to impulsivity and risk-taking, there are also important differences in these constructs and their relationship to the stages of working memory during adolescence.     

Latent classes of heroin and cocaine users predict unique HIV/HCV risk factors

Background

Patterns of heroin and cocaine use vary and may be associated with unique risk factors for bloodborne infections.

Methods

Latent class analysis identified sub-populations of 552 heroin and cocaine users in Baltimore, Maryland. Using latent class regression, these classes were analyzed for associations with demographic characteristics, risky behaviors, Hepatitis C, and HIV.

Results

Three classes were found: Crack/Nasal-Heroin users (43.5%), Polysubstance users (34.8%), and Heroin Injectors (21.8%). Compared to Polysubstance users, Crack/Nasal-Heroin users were almost 7 times more likely to identify as Black (OR = 6.97, 95% CI = 4.35–11.2). Sharing needles was over 2.5 times more likely among Polysubstance users than among Heroin Injectors (OR = 2.66, 95% CI = 1.49–4.75). Crack/Nasal-Heroin users were 2.5 times more likely than Polysubstance users to exchange drugs for sex (OR = 2.50, 95% CI = 1.22–5.13). Crack/Nasal-Heroin users were less likely than Heroin Injectors to have Hepatitis C (OR = 0.10, 95% CI = 0.06–0.18), but no significant differences were found for HIV.

Conclusions

Subpopulations of cocaine and heroin users differed in demographic classifications, HIV-risk behaviors, and Hepatitis C infection. All subpopulations included substantial numbers of HIV-positive individuals. Findings provide further evidence that non-injection drug users face significant infectious disease risk.