Differences in impulsivity and risk-taking propensity between primary users of crack cocaine and primary users of heroin in a residential substance-use program

Crack cocaine use is more associated with impulsivity and a propensity to take risks than heroin use, yet no studies have examined this relationship in the absence of acute drug effects. The current study examined impulsivity (using the Delay Discounting Task) and risk-taking propensity (using the Balloon Analogue Risk Task) across independent groups of primary crack cocaine users with minimal heroin use (n = 16) and primary heroin users with minimal crack cocaine use (n = 11) in residential treatment, with all participants drug abstinent during participation. Crack cocaine users evidenced greater levels of impulsivity and risk-taking propensity, with only the difference in impulsivity persisting after controlling for age and gender. These data hold potential theoretical importance in understanding differences between crack cocaine and heroin users, as the findings cannot be attributed solely to acute pharmacological drug effects.     

Routes of drug administration, differential affiliation, and lifestyle stability among cocaine and opiate users: implications to HIV prevention

Types of drugs used and routes of administration were assessed, and correlations to social affiliation, HIV status, and lifestyle stability were explored among 672 street-recruited drug users in Baltimore. Participants reported 63 patterns of drug use, which were categorized into five groups: (1) only sniff heroin; (2) smoke crack and may snort cocaine; (3) sniff heroin and smoke crack; (4) inject heroin and cocaine; and (5) inject heroin and cocaine, smoke crack, and may snort heroin. Social network analysis revealed that heroin sniffers and crack smokers both tended to associate with those with similar drug use patterns. High symptoms of drug dependence were observed among heroin users irrespective of mode of administration. Injectors reported higher rates of hospitalization compared to noninjectors even after adjusting for HIV status. Implications to HIV prevention and drug use transitions are discussed.     

Risk factors in the relationship between gender and crack/cocaine

Female inner-city substance users evidence greater crack/cocaine use and are more likely to be dependent on this drug than on any other drug. Additionally, female inner-city substance users evidence greater crack/cocaine use and are more likely to be dependent on this drug than their male counterparts, despite no consistent difference demonstrated in use and dependence across other drugs. Because no published work has empirically examined the factors underlying this link between females and crack/cocaine, the current study examined the role of theoretically relevant personality and environmental variables. Among 152 (37% female) individuals in a residential substance-use treatment program, females evidenced greater use of crack/cocaine (current and lifetime heaviest) and were significantly more likely to evidence crack/cocaine dependence than their male counterparts. In contrast, no gender differences were found for any other substance across alcohol, cannabis, and hallucinogens (including PCP). Surprisingly, females were more impulsive than their male counterparts, with impulsivity serving as a risk factor in the relationship between gender and crack/cocaine dependence and lifetime heaviest use. Females also evidenced higher levels of negative emotionality and childhood abuse, but neither variable served as a risk factor in the relationship between gender and crack/cocaine dependence or use. Limitations and future directions are discussed, including the need for further exploration of impulsivity across its various dimensions as well as the inclusion of additional variables such as social context variables to account more fully for this complex link between gender and crack/cocaine.     

An enumeration method of determining the prevalence of users and operatives of cocaine and heroin in Central Harlem

INTRODUCTION: The investigators estimated the number and characteristics of crack, powder cocaine and heroin users and distributors ("operatives") in Central Harlem. METHODS: Central Harlem was divided into 45 primary sampling units (PSUs) with 2 years of drug allegation data from the New York Police Department (NYPD) organized in three strata, those having high, middle or low levels of allegations. In nine randomly selected PSUs, interviewers employed chain referral sampling procedures that were steered by using a nomination technique. RESULTS: Within sampled PSUs, 657 respondents nominated 5756 others for a total of 6413. Seven indicators identified 1007 unique individuals among 2835 nominated by two or more respondents, totaling to 4585 unique persons. These drug users and operatives were divided by the total number of persons in these PSUs according to the 1990 census to estimate the number of drug users and distributors in the 36 PSUs not sampled and for all 98,725 residents of Central Harlem. Approximately 13.4% of Central Harlem residents were estimated to be users of crack, powder cocaine and/or heroin with no roles in drug distribution. Approximately 6.7% of Central Harlem residents were estimated to be operatives of these drugs, some of whom may also have been users. CONCLUSIONS: Enumeration techniques can be a basis for projecting prevalence estimates for crack, powder cocaine and heroin users and operatives in a large urban geographic area.     

Heroin and amphetamine users display opposite relationships between trait and neurobehavioral dimensions of impulsivity

The multidimensional construct of impulsivity is implicated in all phases of the addiction cycle. Substance dependent individuals (SDIs) demonstrate elevated impulsivity on both trait and laboratory tests of neurobehavioral impulsivity; however our understanding of the relationship between these different aspects of impulsivity in users of different classes of drugs remains rudimentary. The goal of this study was to assess for commonalities and differences in the relationships between trait and neurobehavioral impulsivity in heroin and amphetamine addicts. Participants included 58 amphetamine dependent (ADIs) and 74 heroin dependent individuals (HDIs) in protracted abstinence. We conducted Principal Component Analyses (PCA) on two self-report trait and six neurobehavioral measures of impulsivity, which resulted in two trait impulsivity (action, planning) and four neurobehavioral impulsivity composites (discriminability, response inhibition efficiency, decision-making efficiency, quality of decision-making). Multiple regression analyses were used to determine whether neurobehavioral impulsivity is predicted by trait impulsivity and drug type. The analyses revealed a significant interaction between drug type and trait action impulsivity on response inhibition efficiency, which showed opposite relationships for ADIs and HDIs. Specifically, increased trait action impulsivity was associated with worse response inhibition efficiency in ADIs, but with better efficiency in HDIs. These results challenge the unitary account of drug addiction and contribute to a growing body of literature that reveals important behavioral, cognitive, and neurobiological differences between users of different classes of drugs.     

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.     

Prescribing drug of choice to opiate dependent drug users: a comparison of clients receiving heroin with those receiving injectable methadone at a West London drug clinic

Fifty-eight long-term treatment resistant opiate-dependent drug users were offered the choice of receiving injectable heroin or injectable methadone at a West London drug clinic. Drugs were dispensed on-site at the clinic with weekend take-home. There was no routine ongoing supervised injecting. A ceiling dose of 200 mg/day of heroin or methadone was set. One-third chose injectable methadone. Compared to those choosing heroin, these drug users were less likely to have used heroin or crack/cocaine before entering treatment, and were more likely to have previously received treatment with injectable methadone. Drug users reported choosing methadone because it was their primary drug of addiction, and compared with heroin has a longer duration of action and increased strength. Problems with each drug were reported: those choosing heroin complained that the upper dose limit was too low to maintain them adequately, and some receiving methadone complained of discomfort while injecting intravenously. While those choosing each drug had different baseline characteristics, both groups were well retained in treatment and at 3 months made significant reductions in drug use and crime, which were sustained over the 12-month follow-up period. There was no significant difference between treatment outcome between each group. There is an urgent need to conduct randomized controlled trials to establish the effectiveness of prescribing injectable methadone and heroin to inform policy and practice.     

Adversity among drug users: relationship to impulsivity

Illicit substance users experience adverse life events, but few studies have examined the role of impulsivity in these events. The present investigation sought to establish a link between negative life experiences and a trait measure of impulsivity and demonstrate that this association remains even accounting for potential confounds. Participants were 330 heroin and cocaine users recruited from the community for a health service research study. Participants completed a structured interview that assessed topics including drug and alcohol use, impulsivity, and negative life events. This group of drug users reported high rates of adverse life events in the 6 months prior to the assessment. No specific substance abuse/dependence diagnosis or combination of diagnoses was associated with adversity. Number of substance-related diagnoses was associated with adverse life events, but not when adjusting for impulsivity. Experience of these events was significantly associated with impulsivity (p<.001), above and beyond the shared relation with demographic variables, substance abuse and dependence, and number of substance-related diagnoses. These findings document the high frequencies of recent adverse life events among illicit drug users and indicate that trait impulsivity is associated with increased risk of these life events.     

Cigarette smoking, illicit drug use, and routes of administration among heroin and cocaine users

Cigarette smoking is ubiquitous among illicit drug users. Some have speculated that this may be partially due to similarities in the route of administration. However, research examining the relationship between cigarette smoking and routes of administration of illicit drugs is limited. To address this gap, we investigated sociodemographic and drug use factors associated with cigarette smoking among cocaine and heroin users in the Baltimore, Maryland community (N=576). Regular and heavy cigarette smokers were more likely to be White, have a history of a prior marriage, and have a lower education level. Regular smoking of marijuana and crack was associated with cigarette smoking, but not heavy cigarette smoking. Injection use was more common among heavy cigarette smokers. In particular, regular cigarette smokers were more likely to have a lifetime history of regularly injecting heroin. Optimal prevention and treatment outcomes can only occur through a comprehensive understanding of the interrelations between different substances of abuse.     

Contrasting Trajectories of Heroin,Cocaine, and Methamphetamine Use

ABSTRACT

Current literature has shown that heroin addiction is characterized by long periods of regular use persisting over the life course, whereas the course of stimulant use is less understood. The current study examined long-term trajectories of drug use for primary heroin, cocaine (crack/powder cocaine), and methamphetamine (meth) users. The analyses used data from five studies that collected longitudinal information using the Natural History Instrument, including 629 primary heroin users, 694 cocaine users, and 474 meth users. Drug use trajectories over the 10 years since initiation demonstrated the persistence of use over time for all three drugs, with heroin use at the highest level (13 to 18 days per month), cocaine at the lowest level (8 to 11 days), and meth in between (approximately 12 days per month). Application of growth mixture models revealed five distinctive groups: Consistently High Use (n = 545), Increasing Use (n = 260), Decreasing Use (n = 254), Moderate Use (n = 638), and Low Use (n = 100). Heroin users were disproportionately overrepresented in the Consistently High Use group and underrepresented in the Low Use group; cocaine and meth users were mostly in the Moderate Use group. Users in the High Use group also had earlier onsets of drug use and crime, longer incarceration durations, and were the least employed. Clinical/service policy and practice need to recognize and adapt to the specific patterns and needs of users of different drugs while being mindful of the stage drug users are at in their life course.     

Contrasting trajectories of heroin, cocaine, and methamphetamine use

Current literature has shown that heroin addiction is characterized by long periods of regular use persisting over the life course, whereas the course of stimulant use is less understood. The current study examined long-term trajectories of drug use for primary heroin, cocaine (crack/powder cocaine), and methamphetamine (meth) users. The analyses used data from five studies that collected longitudinal information using the Natural History Instrument, including 629 primary heroin users, 694 cocaine users, and 474 meth users. Drug use trajectories over the 10 years since initiation demonstrated the persistence of use over time for all three drugs, with heroin use at the highest level (13 to 18 days per month), cocaine at the lowest level (8 to 11 days), and meth in between (approximately 12 days per month). Application of growth mixture models revealed five distinctive groups: Consistently High Use (n = 545), Increasing Use (n = 260), Decreasing Use (n = 254), Moderate Use (n = 638), and Low Use (n = 100). Heroin users were disproportionately overrepresented in the Consistently High Use group and underrepresented in the Low Use group; cocaine and meth users were mostly in the Moderate Use group. Users in the High Use group also had earlier onsets of drug use and crime, longer incarceration durations, and were the least employed. Clinical/service policy and practice need to recognize and adapt to the specific patterns and needs of users of different drugs while being mindful of the stage drug users are at in their life course.     

Sexual risk and HIV infection among drug users in New York City: a pilot study

Measures of sexual health were assessed during 2008-2009 in a New York City sample of 102 injection and noninjection users of heroin, cocaine, or crack. There was considerable overlap and transitioning between crack smoking and injecting. Crack users were also significantly more likely to be gay, lesbian, or bisexual than other drug users. In multivariate analysis, HIV infection was independently associated with crack use and with being gay or bisexual. In New York City, HIV prevention for drug users has focused on syringe access, safe injection, and drug user treatment, but further progress in HIV control will require strategies to address sexual health among people who use drugs. The study's limitations are noted.     

Street-outreach improves detection but not referral for drug users with latent tuberculosis, New York City

Street outreach in two New York City communities, Harlem and the South Bronx, between May 2001 and March 2003, provided tuberculin skin test (TST) screening to illicit drug users outside the traditional health care system. Persons who used heroin, cocaine, and/or crack were offered a TST, incentives to return for TST reading, and further evaluation if TST was positive. Of 809 participants, 530 (66%) accepted a TST and 81% (429/530) returned for TST reading. Of 429 participants, 40 (9%) were TST positive. Participants found TST positive did not differ from those found TST negative in previous drug user treatment or drug use practices including snorting heroin, sniffing cocaine, smoking crack, and injecting drugs of any kind. Of the 40 participants found TST positive, the 21 who tested TST positive for the first time were more likely to be male (p = .03) and noninjectors (p = .02), than the 19 who had tested TST positive in the past. Only two newly identified persons pursued follow-up care. Street recruitment expanded testing. Better follow-up strategies are needed. The study's limitations are noted.     

Polysubstance use among alcoholics.

Contemporary alcoholics often use multiple substances, but there is little systematic research on this. This study examines the drug use comorbidity of alcoholics (DSM diagnosis, frequency and quantity of drug use); the relationship between drinking and drug use; the relative severity of alcohol- and drug-related problems; and the validity of reports of illicit drug use. Data on substance use were collected from 248 treatment-seeking alcoholics using an expanded Time-line Follow-Back (TLFB) interview. Self-reports of substance use were validated with data from biological specimens (urine and hair). Lifetime diagnosis of joint alcohol and drug dependence/abuse was 64%. Two-thirds (68%) reported using drugs in the past 90 days: 33% powder cocaine; 29% crack cocaine; 15% heroin, and 24% cannabis. The mean proportions of exposed days on which users reported consuming a substance were 57% (alcohol), 26% (powder cocaine), 46% (crack cocaine), 47% (heroin), and 29% (cannabis). Subjects reported consuming an average of 14 standard drinks on a drinking day and $67 worth of drugs on a using day. Drug users reported drinking less than nonusers on a drinking day. Frequency of drinking and drug use were positively correlated; almost all drug users reported simultaneous drinking and drug use; and they rated drugs as the bigger problem. Considerable under-reporting of drug use occurred for the previous 3-4 days, but was more accurate for the previous month.     

Multiple drug use: patterns and practices of heroin and crack use in a population of opiate addicts in treatment

One hundred and sixteen opiate addicts attending treatment services in south London were interviewed about their drug use patterns. In the month before interview, 90% reported heroin use, while 60% had used crack cocaine and 58% alcohol. In the same period, 70% of participants reported multiple drug use, particularly concurrent heroin and crack cocaine use. Of the patients who reported using other drugs with heroin, two-third used crack cocaine, 11% diazepam, 9% methadone and 8% cocaine powder. Twenty-six per cent of crack users sample had injected crack cocaine, which provides confirmation of the increasing prevalence of this recent trend in studies using similar samples. Male participants were significantly more likely to use benzodiazepines with heroin, while women were more likely to use crack alongside heroin (and used larger quantities). These findings have implications for the treatment and management of multiple drug users, for whom opiates may be only a part of their drug-using repertoire.     

Supporting the habit: income generation activities of frequent crack users compared with frequent users of other hard drugs.

US Federal sentencing guidelines punish possession of crack cocaine very differently from powder cocaine, based partially upon the assumption that crack users engage more frequently in criminal behavior to pay for their habit. This article analyzed frequent users (those who have used at least 15 of the last 30 days) of crack with subgroups of less frequent hard drug users in terms of various income generation activities reported during the past 30 days. The sample consists of 602 African-Americans who were current (in past 30 days) users or sellers of cocaine powder, crack, and heroin. They were carefully recruited from randomly selected blocks in the Central Harlem area of New York City and interviewed extensively in 1998-1999. Their IGAs were classified into six categories. Compared with not-frequent (less than 15 days) hard drug users, frequent crack and multiple hard drug users were equally likely to be involved in drug distribution activities, but were significantly less likely to have full-time jobs, part-time jobs, aid to families with dependent children or welfare support. They had much higher odds ratios for non-drug related illegal (theft mainly) income generation activities and sex work among women. Often, gender and birth cohort variables had higher odds ratios with specific income generation activities than the frequent use of the primary drug(s). This evidence suggests that very frequent crack users have been stigmatized by, are largely excluded from, and perform very marginal economic roles in the legal economic system (jobs and welfare), the illegal economic system, and even in the hard drug distribution system.     

The attitudes of heroin users and matched non-users to drugs and drug users.

Compared with matched controls, heroin users were more tolerant of substance use and perceived themselves as slightly more unemployed, depressed, neat and aggressive. Both groups thought crack cocaine, heroin and alcohol dangerous. Heroin users were most in favour of cannabis, followed by controls who had used cannabis, with only controls who had never used cannabis being against it. It is concluded that the stereotype of a heroin user was not strongly believed by these heroin users or their peers.     

Factors for employment: a case-control study of fully employed and unemployed heroin users

The purpose of this article is to characterize fully employed users of heroin, compare them with their unemployed counterparts, and identify demographic, human, and social capital and drug misuse factors that are differentially associated with full employment. A nested case-control research design was used to identify 122 fully employed users (cases) and 466 unemployed users (controls) from a larger study of African American, Hispanic, and non-Hispanic White men and women who were active heroin injectors and sniffers and recruited from the streets of Miami-Dade County, Florida, between July 1997 and February 2000. Multivariate logistic regression techniques were used to analyze data from the Modified AIDS Risk Behavior Questionnaire. Findings indicated that employed users were more likely to possess human capital and social capital and less likely to use crack cocaine than unemployed users. Intervention to increase and sustain the employability of persons who misuse heroin is essential. Protocols that enhance human capital and social capital and reduce the misuse of drugs will benefit programs that seek to improve the employment status of persons who misuse heroin. The study's limitations are noted.