Crack cocaine trajectories among users in a midwestern American city

Peripheral neurotrophin levels during controlled crack/cocaine abstinence: a systematic review and meta-analysis

Cocaine/crack abstinence periods have higher risk of relapse. Abstinence as initial part of the recovery process is affected by learning and memory changes that could preserve the addictive cycle. To further understand how the interruption of cocaine/crack consumption affects neurotrophin level we performed the present systematic review and meta-analysis following the PRISMA statement (number CRD42019121643). The search formula was conducted in PubMed, Web of Science, Embase, ScienceDirect, and Google Scholar databases. The inclusion criterion was cocaine use disorder in 18 to 60-year-old people, measuring at least one neurotrophin in blood before and after a controlled abstinence period. Studies without pre-post design were excluded. Five investigations had nine different reports, four of them were subjected to a meta-analysis (n = 146). GRADE risk of bias method was followed. Individual studies reported increased peripheral brain derived neurotrophic factor (BDNF) after abstinence, evidence pooled by Hedge's g showed no significant change in BDNF after abstinence. Relevant heterogeneity in the length of the abstinence period (12-32 days), last cocaine/crack consumption monitoring and blood processing were detected that could help to explain non-significant results. Further improved methods are suggested, and a potential BDNF augmentation hypothesis is proposed that, if true, would help to understand initial abstinence as a re-adaptation period influenced by neurotrophins such as the BDNF.

Patterns of reduced use and abstinence in multi-site randomized controlled trials of pharmacotherapies for cocaine and methamphetamine use disorders

BACKGROUND

Many individuals with cocaine or methamphetamine use disorders who enter treatment do not achieve abstinence but reduce their use of the target drug. We aimed to compare change in pattern of drug use (i.e., achieving "abstinence", "reduced use" or no reduction in use) among participants in randomized controlled trials (RCTs) of treatment of cocaine and methamphetamine use disorder, irrespective of the type of treatment.

METHODS

The data were drawn from 10 multi-site pharmacotherapy RCTs of cocaine (n = 1,134) and methamphetamine (n = 555) use disorders. The outcome patterns and their sociodemographic and clinical correlates were compared in cocaine and methamphetamine RCTs, using multinomial logistic regression models. Analyses were adjusted for missing data, clustering within RCTs, socio-demographic and baseline clinical characteristics, and treatment arms.

RESULTS

Those in cocaine RCTs were more likely to experience reduced use compared to participants in methamphetamine RCTs (20.6% vs. 13.2%, respectively), but less likely to experience "abstinence" (7.6% vs. 20.3%; Chi-squared = 14.20, df = 2, P < 0.001). Differences in "abstinence" persisted after adjustment for baseline covariates. Association of sociodemographic and clinical correlates with outcomes differed in cocaine and methamphetamine RCTs.

CONCLUSION

A sizeable proportion of individuals in RCTs of pharmacological treatment for stimulant use disorder who do not attain "abstinence" nevertheless reduce their use. The outcome patterns of drug use are different for cocaine and methamphetamine use disorders and reliance on abstinence as the sole outcome may obscure these differences.

Identification of Typologies of Cocaine Use Based on Quantity, Frequency, and Duration of Use: A Latent Profile Analysis

OBJECTIVES

We identified the patterns of cocaine use during individuals' heaviest use period by considering quantity, frequency, and duration simultaneously and examined the correlates and risk profile for these patterns.

METHODS

Latent profile analysis was conducted among the 3117 individuals who reported lifetime use of cocaine in the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) with quantity, frequency, and duration used as indicators. Logistic regression analyses examined factors associated with subtype membership based on patterns of cocaine use and the relationships between these patterns and cocaine use disorder (CocUD) and its severity.

RESULTS

Four patterns were identified: a "low use" class (72.6%), a "moderate use" class (8.2%), a "daily use" class (17.9%), and a "very high quantity use" class (1.3%). Relative to non-Hispanic White and the "low use" class, non-Hispanic Black was associated with increased odds to be in the "moderate use" and "daily use" classes. Higher prevalence of smoking crack cocaine and poly-route use was observed among the "very high quantity use" class relative to other classes; increased risk of using other substances was associated with the "daily use" class. Higher levels of cocaine use were associated with higher risks of CocUD and worse severity compared to the "low use" class.

CONCLUSIONS

People who use cocaine are heterogeneous with different patterns of use and risks of CocUD. Reducing cocaine smoking and poly-route of use should be placed as the same priority as decreasing very high quantity of use in interventions.

Patterns of Cocaine Use During Treatment: Associations With Baseline Characteristics and Follow-Up Functioning

OBJECTIVE

Abstinence outcomes are typically prioritized in the treatment of cocaine use disorder while ignoring patterns of low-frequency cocaine use. This study examined patterns of cocaine use frequency during treatment and evaluated how these patterns related to baseline characteristics and functioning outcomes 6 and 12 months after treatment.

METHOD

We used a pooled dataset (N = 720) from seven randomized clinical trials for cocaine use disorder. The Addiction Severity Index (ASI) was used to assess functioning. Repeated-measures latent class analysis was used to derive patterns of cocaine use.

RESULTS

Three patterns were identified: abstinence (10.6%), low-frequency use (approximately 1 day/week; 66.3%), and persistent frequent use (approximately 4 days/week; 23.1%). The low-frequency group was associated with male gender, younger age, and a criminal justice referral. The abstinent group had the highest alcohol problem severity score at baseline. At Month 6, the low-frequency group reported lower problem severity than the persistent frequent use group across multiple ASI areas, including the cocaine use as well as psychological, family, employment, and legal domains. At Month 12, the low-frequency group did not differ from the abstinent group in problem severity on any ASI domain and, relative to the persistent frequent use group, had lower cocaine use and employment problem severity.

CONCLUSIONS

These findings highlight the importance of adopting a harm reduction approach and recognizing the potential clinical benefits associated with nonabstinent outcomes.

Health outcomes associated with crack-cocaine use: Systematic review and meta-analyses

BACKGROUND

Crack-cocaine use is prevalent largely in socio-economically marginalized populations in the Americas. Its use has been associated with diverse health outcomes, yet no recent or systematic reviews of these exist.

METHODS

A systematic review of health outcomes associated with crack-cocaine use was performed, using MEDLINE, Scopus, Web of Science, CINAHL, PsycINFO, and LILACS up to October 2016. Search terms included crack-cocaine and health outcome-related keywords, targeting peer-reviewed studies on quantified health outcomes associated with crack-cocaine use. Random effects meta-analyses produced pooled odds ratios. Levels of evidence for major results were assessed using the GRADE approach. A review protocol was registered with PROSPERO (CRD42016035486).

RESULTS

Of 4700 articles returned, 302 met eligibility criteria, reporting on health outcomes for 14 of 22 ICD-10 chapters. Conclusive evidence and meta-analyses showed positive associations between crack-cocaine use and blood/sexually transmitted diseases (HIV and hepatitis C virus, others); moderate evidence and meta-analyses supported associations with neonatal health, and violence. There were mixed associations for mental and other health outcomes, yet insufficient evidence to perform meta-analyses for many categories (e.g., mortality). Most underlying research was of limited or poor quality, with crack-cocaine commonly assessed as a secondary covariate.

CONCLUSIONS

Crack-cocaine use was associated with a range of health outcomes, although it was unclear if there was direct causal impact, interactions between risk factors, or external drivers of both crack-cocaine use and outcomes. Rigorous epidemiological studies are needed to systematically assess health outcomes of crack-cocaine use and underlying pathways, also to inform evidence-based interventions.

Addictions Neuroclinical Assessment: A Neuroscience-Based Framework for Addictive Disorders

This article proposes a heuristic framework for the Addictions Neuroclinical Assessment that incorporates key functional domains derived from the neurocircuitry of addiction. We review how addictive disorders (ADs) are presently diagnosed and the need for new neuroclinical measures to differentiate patients who meet clinical criteria for addiction to the same agent while differing in etiology, prognosis, and treatment response. The need for a better understanding of the mechanisms provoking and maintaining addiction, as evidenced by the limitations of current treatments and within-diagnosis clinical heterogeneity, is articulated. In addition, recent changes in the nosology of ADs, challenges to current classification systems, and prior attempts to subtype individuals with ADs are described. Complementary initiatives, including the Research Domain Criteria project, that have established frameworks for the neuroscience of psychiatric disorders are discussed. Three domains-executive function, incentive salience, and negative emotionality-tied to different phases in the cycle of addiction form the core functional elements of ADs. Measurement of these domains in epidemiologic, genetic, clinical, and treatment studies will provide the underpinnings for an understanding of cross-population and temporal variation in addictions, shared mechanisms in addictive disorders, impact of changing environmental influences, and gene identification. Finally, we show that it is practical to implement such a deep neuroclinical assessment using a combination of neuroimaging and performance measures. Neuroclinical assessment is key to reconceptualizing the nosology of ADs on the basis of process and etiology, an advance that can lead to improved prevention and treatment.

Multiplex crack smoking and sexual networks: associations between network members' incarceration and HIV risks among high-risk MSM

This study examined HIV risks in the multiplex crack-smoking and sexual networks of incarcerated drug-using men who have sex with men (MSM) and their associates. We estimated the associations between the network members' incarceration, self-reported HIV infection, and trading sex for money. Our analytic sample consisted of 508 crack-smoking or sexual partnerships of 273 high-risk MSM. Network members were specified by (1) crack smoking and sexual behavior or (2) crack smoking only. Longer incarceration of the crack-smoking and sexual network members was associated with self-reported HIV infection (AOR = 1.61, p < 0.05), which extended up to one's partners' partners' partners (AOR = 1.63, p < 0.05). Similar results were found for trading sex (AOR = 2.77, p < 0.05). The findings of the study call for the development of a system-level HIV intervention among former incarcerated MSM and their associates.

Examining Risk for Frequent Cocaine Use: Focus on an African American Treatment Population

BACKGROUND

Cocaine use and its consequences are disproportionately higher and more severe among African Americans compared to other ethnic/racial groups.

OBJECTIVES

The aims of this study were to examine a risk model specific for African American users and assess whether risk varies as a function of sex.

METHODS

270 African American adults in a residential drug treatment facility completed measurements assessing first and past year crack/cocaine use frequency, childhood trauma, and stress reactivity. Multiple linear regression analysis was used to examine the unique effect of each predictor variable on past year crack/cocaine frequency. Sex was included as a moderator variable in the regression analysis.

RESULTS

All predictor variables were positively correlated with past year crack/cocaine use. However, sex differences were also observed: females reported higher rates of childhood emotional abuse, childhood sexual abuse, and stress reactivity-as well as past year crack use and cocaine use-than males. Regression analyses were performed with sex, first year use, and stress reactivity emerging as the only significant predictors for frequency of crack and cocaine use among all study participants. Moreover, sex differences were observed in the influence of first year crack use frequency on past year crack use frequency, such that the effect was stronger for males than for females. Conclusion/Importance: This study offers a clearer understanding of the risk factors for crack and cocaine abuse specific to African Americans, as well as sex specific pathways to risk, providing useful implications for future prevention and treatment efforts.

Comportamento violento entre usuários de crack

<p>Considerando a relevância do uso abusivo de crack na atualidade brasileira e sua relação com a violência, este estudo propõe-se a analisar a associação entre comportamento violento —delitivo, auto e hetero<br />agressivo— entre os usuários de crack e variáveis sociodemográficas e de uso de drogas. Realizado estudo quantitativo, transversal, com amostra de conveniência, com 72 homens usuários de crack em tratamento nas Comunidades Terapêuticas de seis cidades da região Oeste<br />do Estado de Minas Gerais (Brasil). Os dados foram analisados estatisticamente no Statistical Package for<br />the Social Sciences Versão 17.0, utilizando-se teste qui-quadrado para verificação de diferenças estatisticamente<br />significantes. Os resultados apontam associação do tráfico com número de pedras consumidas e de tratamentos realizados; de prisão ou detenção com baixa escolaridade,<br />ser solteiro e idade de início do uso de droga ilícita; de tentativa de suicídio com o tempo máximo de<br />abstinência e de heteroagressão com idade de início do uso de droga ilícita e frequência diária do uso de crack. O uso de crack pode contribuir para o desenvolvimento de comportamento violento —delitivo, auto e heteroagressivo.</p>

Trajectory of substance use after an HIV risk reduction intervention

BACKGROUND

Research assessments can confound the results of treatment outcome studies and can be themselves an intervention or form of aftercare.

OBJECTIVE

To determine the trajectory of substance use and substance severity in a sample of African American cocaine users participating in a community-based sexual risk reduction trial.

METHODS

Out-of-treatment participants were recruited using Respondent-Driven Sampling in two African American majority counties in rural Arkansas. They participated in either the sexual risk reduction condition or an active control focused on access to social services. They were interviewed at baseline, post-intervention, and 6 and 12 months post-intervention. Substance use outcome measures were use of crack cocaine, powder cocaine, marijuana, alcohol, and the Addiction Severity Index Alcohol and Drug Severity composites. A random sample of participants completed qualitative interviews post-12-month interview.

RESULTS

251 were enrolled. Substance use outcomes did not differ among the two conditions at any point in the study. Use of measured substances and the ASI composites significantly decreased between baseline and post-intervention (p < 0.01), decreases that persisted at the 12-month assessment period compared to baseline. Qualitative findings suggested that many participants identified increased awareness of their drug use and need to control it through the programs. Participants also noted strong bonding with interviewers.

CONCLUSION

Clinical trials may have positive unexpected outcomes in terms of reduced substance use even though the trial is not substance use focused. Behavioral interventions for drug users that are not focused specifically on reducing drug use may nonetheless have unanticipated positive associations with reductions in drug use.

Effectiveness of secondary prevention and treatment interventions for crack-cocaine abuse: a comprehensive narrative overview of English-language studies

There are an estimated several million crack-cocaine users globally; use is highest in the Americas. Most crack users are socio-economically marginalized (e.g., homeless), and feature elevated risks for morbidity (e.g., blood-borne viruses), mortality and crime/violence involvement, resulting in extensive burdens. No comprehensive reviews of evidence-based prevention and/or treatment interventions specifically for crack use exist. We conducted a comprehensive narrative overview of English-language studies on the efficacy of secondary prevention and treatment interventions for crack (cocaine) abuse/dependence. Literature searches (1990-2014) using pertinent keywords were conducted in main scientific databases. Titles/abstracts were reviewed for relevance, and full studies were included in the review if involving a primary prevention/treatment intervention study comprising a substantive crack user sample. Intervention outcomes considered included drug use, health risks/status (e.g., HIV or sexual risks) and select social outcome indicators. Targeted (e.g., behavioral/community-based) prevention measures show mixed and short-term effects on crack use/HIV risk outcomes. Material (e.g., safer crack use kit distribution) interventions also document modest efficacy in risk reduction; empirical assessments of environmental (e.g., drug consumption facilities) for crack smokers are not available. Diverse psycho-social treatment (including contingency management) interventions for crack abuse/dependence show some positive but also limited/short-term efficacy, yet likely constitute best currently available treatment options. Ancillary treatments show little effects but are understudied. Despite ample studies, pharmaco-therapeutic/immunotherapy treatment agents have not produced convincing evidence; select agents may hold potential combined with personalized approaches and/or psycho-social strategies. No comprehensively effective 'gold-standard' prevention/treatment interventions for crack abuse exist; concerted research towards improved interventions is urgently needed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predictors of change in cocaine use in a street-recruited cohort of young cocaine users

AIM

To determine predictors of changes in amount of cocaine use among regular users outside treatment services.

DESIGN

Longitudinal study-we estimated the proportion of subjects who increased or decreased cocaine use and assessed possible predictors related to these changes among a street-recruited cohort of young regular cocaine users (RCU).

SETTING

Three Spanish cities: Barcelona, Madrid and Seville

PARTICIPANTS

A total of 720 RCU aged 18-30 years not regularly using heroin were recruited in the community during 2004-06 (Itinere Project). Follow-up interviews (n = 501) were carried out at 12-24 months.

MEASUREMENTS

The average amount of cocaine used weekly was calculated taking into account the number of days of use and the usual quantity (g/day). A multinomial logistic regression approach was used to investigate the association between changes in amount of cocaine use (i.e. difference exceeded 33.3% of baseline level) after 12-24 months, and baseline socio-demographic characteristics, nightlife, patterns of cocaine use and use of alcohol and other psychoactive drugs.

FINDINGS

Cocaine use baseline average level was 2.14 g/week [95% confidence interval (CI) = 2.02-2.42]. It decreased in 71.5% of subjects and increased in 14.1%. In multinomial analysis, negative associations were found between decreasing cocaine use and high levels of alcohol consumption and using an increasing number of psychoactive drugs. Moreover, low education level, having used cocaine frequently in houses and reporting cocaine binges were associated with increasing cocaine use.

CONCLUSIONS

A street-recruited cohort of cocaine users in Spain showed a significant reduction in cocaine use over a period of 12-24 months. High consumption of alcohol and increasing use of other psychoactive drugs decreased the probability of reducing cocaine use.

Current interventions to reduce sexual risk behaviors and crack cocaine use among HIV-infected individuals

The dual global epidemics of crack cocaine use and HIV have resulted in a large number of people living with HIV who use crack cocaine, many of whom continue to engage in unprotected sex. Crack use also increases the rate of HIV progression. Consequently, there is an urgent need for effective interventions to decrease crack use and unprotected sex and to improve antiretroviral therapy (ART) adherence in this population. This article reviews the recent published literature on interventions for reducing crack use and unprotected sex among people living with HIV. Only a few intervention outcome studies targeting exclusively HIV positive crack cocaine users were identified, whereas other studies used a mixed sample. Some interventions focused on reducing crack use and several focused on reducing sex-risk behaviors. Consequently, there is a critical need for efficacious interventions that address crack use, risky sex and ART adherence among people living with HIV.

Treatment of female and male inpatient crack users: a qualitative study

OBJECTIVE: To map treatment trajectories in a sample of male and female crack users through their narratives about the course of treatment seeking and their attempts to access health care services in Brazil. METHODS: Qualitative study of a purposive sample (five female and nine male hospitalized crack users) using semi-structured interviews. The interviews were transcribed and data explored using content analysis. RESULTS: Respondents reported difficulties getting access to hospitalization, relapse after discharge, and abandonment of treatment. There seems to be a peculiar model of behavior for women and men while dealing with craving for crack: while women got involved with prostitution and consequently became infected with HIV, every men of the sample reported criminal involvement. CONCLUSIONS: The relationship between relapse and a social environment conducive to consumption, associated with belief or disbelief in spiritual support, prostitution, and the legal complications arising from the use of crack, are relevant issues and should be taken into consideration in the development of preventive actions aimed at this specific population.

Trajectories of drug use and mortality outcomes among adults followed over 18 years

BACKGROUND

For adults in general population community settings, data regarding long-term course and outcomes of illicit drug use are sparse, limiting the formulation of evidence-based recommendations for drug use screening of adults in primary care.

OBJECTIVE

To describe trajectories of three illicit drugs (cocaine, opioids, amphetamines) among adults in community settings, and to assess their relation to all-cause mortality.

DESIGN

Longitudinal cohort, 1987/88-2005/06.

SETTING

Community-based recruitment from four cities (Birmingham, Chicago, Oakland, Minneapolis).

PARTICIPANTS

Healthy adults, balanced for race (black and white) and gender were assessed for drug use from 1987/88-2005/06, and for mortality through 12/31/2008 (n = 4301)

MEASUREMENTS

Use of cocaine, amphetamines, and opioids (last 30 days) was queried in the following years: 1987/88, 1990/91, 1992/93, 1995/96, 2000/01, 2005/06. Survey-based assessment of demographics and psychosocial characteristics. Mortality over 18 years.

RESULTS

Trajectory analysis identified four groups: Nonusers (n = 3691, 85.8%), Early Occasional Users (n = 340, 7.9%), Persistent Occasional Users (n = 160, 3.7%), and Early Frequent/Later Occasional Users (n = 110, 2.6%). Trajectories conformed to expected patterns regarding demographics, other substance use, family background and education. Adjusting for demographics, baseline health status, health behaviors (alcohol, tobacco), and psychosocial characteristics, Early Frequent/Later Occasional Users had greater all-cause mortality (Hazard Ratio, HR = 4.94, 95% CI = 1.58-15.51, p = 0.006).

LIMITATIONS

Study is restricted to three common drugs, and trajectory analyses represent statistical approximations rather than identifiable "types". Causal inferences are tentative.

CONCLUSIONS

Four trajectories describe illicit drug use from young adulthood to middle age. Two trajectories, representing over one third of adult users, continued use into middle age. These persons were more likely to continue harmful risk behaviors such as smoking, and more likely to die.

Factors Affecting the Adequacy and Preferability of Semiparametric Groups-Based Approximations of Continuous Growth Trajectories

Psychologists have long been interested in characterizing individual differences in change over time. It is often plausible to assume that the distribution of these individual differences is continuous in nature, yet theory is seldom so specific as to designate its parametric form (e.g., normal). Semiparametric groups-based trajectory models (SPGMs) were thus developed to provide a discrete approximation for continuously distributed growth of unknown form. Previous research has demonstrated the adequacy of the approximation provided by SPGM but only under relatively narrow, theoretically optimal conditions. Under alternative conditions, which may be more common in practice (e.g., higher dimension random effects, smaller sample sizes), this study shows that approximation adequacy can suffer. Furthermore, this study also evaluates whether SPGM's discrete approximation is preferable to a parametric trajectory model that assumes normally distributed random effects when in fact the distribution is modestly nonnormal. The answer is shown to depend on distributional characteristics of both repeated measures (binary or continuous) and random effects (bimodal or skewed). Implications for practice are discussed in light of empirical examples on externalizing behavior.

Latex agglutination test based on single-chain Fv recombinant antibody fragment

Recombinant antibodies have been proposed as invaluable tools for various therapeutic and diagnostic purposes. Here, we describe the development of a novel latex agglutination test (LAT) using single-chain Fv recombinant antibody fragment for the detection of K99(+) enterotoxigenic Escherichia coli strains. For the production of a single-chain Fv antibody fragment (scFv) against the major colonization factor (FanC) of K99 antigen, the scFv gene was integrated into a bacterial expression vector under the control of T7 promoter. After high-level expression of soluble scFv (approximately 50 mg/l) in flask cultivation of E. coli DE3 and purification, scFv was immobilized on different latex particles, and then, these sensitized beads were used in LAT. Results obtained with our latex reagents revealed that the recombinant antibody-coated particles were able to give a good agglutination signal with purified antigen, intact cells displaying this protein and clinical specimens. The strength of agglutination of scFv-coated beads for antigen was comparable to that of polyclonal anti-K99-coated particles. However, the assay proved to be simple and rapid, similar to conventional LATs, and owing to more convenient and economical production of recombinant antibodies, they can be considered as a useful reagent for replacing monoclonal antibodies in LATs.

Evolution of drug use in a cohort of treated crack cocaine users

OBJECTIVE

To analyze the evolution of drug use among treated crack cocaine users.

METHODS

A cohort originally comprising 131 crack addicts admitted to a detoxification unit in the city of São Paulo, Southeastern Brazil, between 1992 and 1994 were followed up on three occasions: 1995-96, 1998-99, and 2005-06. Variables investigated included demographical data, risky sexual behaviors, intake patterns for crack and other substances, incarceration, disappearance, and death. Statistical analysis was carried out using chi-square tests, multinomial logistic regression and Cox regression.

RESULTS

Among the patients evaluated, 43 were crack-free (12 months or longer), 22 were users, 13 were imprisoned, two were missing, and 27 were deceased. Three groups with distinct post-discharge drug use patterns were identified. Safe sexual behavior (condom use) was correlated with stable abstinence (p=0.001). Positive HIV test upon admission (p=0.046), use of snorted cocaine in the last year (p=0.001), and lifetime use of snorted cocaine (132 months or longer) (p=0.000) were associated with long term use of crack cocaine. History of intravenous cocaine use increased the probability of death at 12 years by 2.5 fold (p=0.031) (95%CI: 1.08; 5.79).

CONCLUSIONS

Recurrence and persistence of crack use in the years following discharge reflect new modalities of drug use. On the other hand, stable abstinence patterns provide evidence of the feasibility of recovery from crack addiction.

"To Numb Out and Start to Feel Nothing": Experiences of Stress Among Crack-Cocaine Using Women in a Midwestern City

The study uses qualitative interviews conducted with 19 crack using women to explore their experiences of stress and their views regarding the relationship between stress and drug use. Fifteen of the women participated in follow-up interviews conducted 5-7 years after the baseline. Life history interviews unveiled a pattern of close connection between the intensity of women's drug use and the level of stress they experienced in relation to their past adversities and current life circumstances. The majority of the women viewed stress as an important causal explanation of their drug use. Tensions related to romantic relationships, traumatic childhood, motherhood failures, unabated grief, and humiliating experiences of "crack life" were discussed as the most common sources of psychosocial stress. Most women had very limited positive coping resources and skills. Crack use was perceived as a very common, although highly maladaptive, way to deal with stress. Implications for interventions are discussed.

Surviving crack: a qualitative study of the strategies and tactics developed by Brazilian users to deal with the risks associated with the drug

BACKGROUND

Due to marginalization, trafficking violence, conflicts with the police and organic and social psychological problems associated with the drug, crack is one of the most devastating drugs currently in use. However, there is evidence that some users manage to stay alive and active while using crack cocaine for many years, despite the numerous adversities and risks involved with this behavior. In this context, the aim of the present study was to identify the strategies and tactics developed by crack users to deal with the risks associated with the culture of use by examining the survival strategies employed by long-term users.

METHOD

A qualitative research method was used involving semi-structured, in-depth interviews. Twenty-eight crack users fulfilling a pre-defined enrollment criterion were interviewed. This criterion was defined as the long-term use of crack (i.e., at least four years). The sample was selected using information provided by key informants and distributed across eight different supply chains. The interviews were literally transcribed and analyzed via content analysis techniques using NVivo-8 software.

RESULTS

There was diversity in the sample with regard to economic and education levels. The average duration of crack use was 11.5 years. Respondents believed that the greatest risks of crack dependence were related to the drug's psychological effects (e.g., cravings and transient paranoid symptoms) and those arising from its illegality (e.g., clashes with the police and trafficking). Protection strategies focused on the control of the psychological effects, primarily through the consumption of alcohol and marijuana. To address the illegality of the drug, strategies were developed to deal with dealers and the police; these strategies were considered crucial for survival.

CONCLUSIONS

The strategies developed by the respondents focused on trying to protect themselves. They proved generally effective, though they involved risks of triggering additional problems (e.g., other dependencies) in the long term.

A prospective study of substance use and housing stability in a homeless population

OBJECTIVES

This study examined self-report and urine test data about homeless substance use over time, prospectively comparing substance use with attainment of stable housing.

METHODS

400 homeless people systematically sampled from shelters and streets in St. Louis, Missouri were assessed with structured diagnostic interviews and urine substance testing annually over 2 years. Nearly two-thirds (n = 255) completed all three assessments, constituting the sample for this prospective study.

RESULTS

More than half (55%) of this homeless sample had detectable cocaine use during the study. Most cocaine users continued using during the next 2 years and failed to achieve and maintain stable housing. Cocaine use in the first follow-up year predicted housing patterns over the next 2 years, independent of lifetime diagnosis of cocaine use disorder. Alcohol abuse/dependence in the 2-year follow-up period did not predict housing outcomes.

CONCLUSIONS

The course of cocaine use and abuse/dependence, but not continuing alcohol addiction, was associated with subsequent attainment of stable housing, especially cocaine use in the first prospective year. Replication of these findings in other locations to determine generalizability may have implications for designing housing service models.

Body mass trajectories through adulthood: results from the National Longitudinal Survey of Youth 1979 Cohort (1981-2006)

BACKGROUND

Most studies describing change in body mass through adulthood model an 'average' trajectory bearing the same functional form in the underlying population. Latent-class growth modelling has revealed the presence of several underlying body mass/obesity trajectory groups among children and adolescents, but has not been applied to capture adult body mass trajectories. We apply the technique to identify adult body mass trajectory groups, risk factors for group membership and (time-varying) modifiers of trajectory level within each group, and assess association between group membership and important health outcomes in midlife.

METHODS

Body mass trajectory groups, from age 18 to 49 years, were identified using latent-class growth modelling based on the National Longitudinal Survey of Youth 1979 (n = 9681). Role of gender, race/ethnicity and age cohort as risk factors for group membership, and of highest grade of education completed, years of urban living, years in employment, years in poverty and years married as modifiers of trajectory level was evaluated.

RESULTS

Four trajectory groups, 'normal weight', 'overweight', 'late adulthood obesity' and 'early adulthood obesity' were identified. Males, Blacks and those born later had higher odds of being in the three latter groups. More education and years married lowered the trajectory within each group. The prevalence of most health outcomes was lowest in the 'normal weight' group, somewhat greater in the 'overweight' group, greater again in the 'late adult obesity group' and highest in the 'early adulthood obesity' group.

CONCLUSION

Regular body mass index screening and monitoring in early adult life may identify a person as belonging to one of these four groups early, and allow the individual and health-care providers opportunities to initiate behavioural or other interventions better tailored to the specific group.

Two-year trajectory of stimulant use in 18- to 21-year-old rural African Americans

Little is known about stimulant use trajectories of rural African American youth. The purpose of the present study is to explore substance use over 24 months in 98 African Americans, ages 18 to 21, who used cocaine or methamphetamine 30 days prior to baseline. The majority was male, unemployed, and had not graduated from high school. At baseline, almost half of the participants met criteria for abuse/dependence of cocaine--the primary stimulant used--which decreased to 25% by the final follow-up. Similar decreases were noted in rates of alcohol and marijuana abuse/dependence, although monthly use remained high. Participants reported minimal utilization of mental health or substance abuse services, but demonstrated significant improvements on physical and mental health measures. In summary, cocaine use declined, but other substances were used at high rates, suggesting a significant need for intervention services that address multisubstance use in rural areas.

Sustainability of intervention effects of an evidence-based HIV prevention intervention for African American women who smoke crack cocaine

BACKGROUND

HIV prevention intervention efficacy is often assessed in the short term. Thus, we conducted a long-term (mean 4.4 years) follow-up of a woman-focused HIV intervention for African American crack smokers, for which we had previously observed beneficial short-term gains.

METHODS

455 out-of-treatment African American women in central North Carolina participated in a randomized field experiment and were followed up to determine sustainability of intervention effects across three conditions: the woman-focused intervention, a modified NIDA intervention, and a delayed-treatment control condition. We compared these groups in terms of HIV risk behavior at short-term follow-up (STFU; 3-6 months) and long-term follow-up (LTFU; average 4 years).

RESULTS

The analyses revealed two distinct groups at STFU: women who either eliminated or greatly reduced their risk behaviors (low-risk class) and women who retained high levels of risk across multiple risk domains (high-risk class). At STFU, women in the woman-focused intervention were more likely to be in the low HIV risk group than the women in control conditions, but this effect was not statistically significant at LTFU. However, low-risk participants at STFU were less likely to be retained at LTFU, and this retention rate was lowest among women in the woman-focused intervention.

CONCLUSIONS

Short-term intervention effects were not observed over 4 years later, possibly due to differential retention across conditions. The retention of the highest risk women presents an opportunity to extend intervention effects through booster sessions for these women.

Longitudinal relationship between psychological distress and multiple substance use: results from a three-year multisite natural-history study of rural stimulant users

OBJECTIVE

Substance use is associated with poor mental health, but little is known regarding how use of multiple substances is associated with mental health, particularly longitudinally, in community studies. This article examines this issue in a large (N = 710), natural-history study of rural stimulant (cocaine and/or methamphetamine) users in three states.

METHOD

Respondent-driven sampling recruited recent (past-30-day) stimulant users in three counties each in Arkansas, Kentucky, and Ohio. Participants were interviewed every 6 months for 3 years. Mental health was measured by the Brief Symptom Inventory, and prior 6 months' substance use was measured for 17 possible substances. Data analysis used generalized estimating equations for longitudinal data with the Global Severity Index of the Brief Symptom Inventory as the dependent variable at each interview and substance use as predictor variables measured by number of substances used in the past 6 months and, separately, the 17 individual substances, adjusting for use of substance-use treatment, demographics, and recruitment site.

RESULTS

On average, both Global Severity Index score and use of many substances declined over the course of study. Global Severity Index score was significantly associated with (a) greater number of substances used in the past 6 months (p < .0001) and (b) use of crack cocaine, methamphetamine, and nonprescription use of prescription painkillers and tranquilizers.

CONCLUSIONS

Multiple and specific substances appear to incrementally increase psychological distress. Users of cocaine and methamphetamine are present in rural areas; these associations with poor psychological health raise concerns regarding availability of local treatment services for individuals with mental-health problems, as well as substance abuse.

Estratégias desenvolvidas por usuários de crack para lidar com os riscos decorrentes do consumo da droga

OBJETIVOS: O objetivo deste estudo foi identificar, sob a ótica de usuários de crack, quais são as estratégias que eles utilizam para minimizar ou evitar os riscos decorrentes do consumo de crack. MÉTODO: Utilizou-se método qualitativo de pesquisa, desenvolvido mediante entrevistas semiestruturadas em profundidade. Foi entrevistada uma amostra intencional por critérios, composta por 30 usuários de crack, selecionados por meio de informantes-chave e distribuídos em oito diferentes cadeias. As entrevistas foram transcritas literalmente, inseridas e analisadas no software NVivo 8, com exploração dos dados mediante a técnica de análise de conteúdo. RESULTADOS: Os entrevistados acreditam que os maiores riscos decorrentes da dependência do crack sejam os relacionados aos efeitos psíquicos da droga, como fissura, sintomas paranoides transitórios e sintomas depressivos, assim como os decorrentes da ilegalidade dela, como a polícia e as questões referentes ao tráfico. Entretanto, os riscos de complicações físicas do consumo quase não foram apontados. As estratégias se concentraram no controle dos efeitos psíquicos, principalmente pelo consumo de álcool e maconha. Para lidar com as consequências da ilegalidade da droga, mostraram se preocupar com a postura que adotam perante o traficante e a polícia. CONCLUSÕES: As estratégias desenvolvidas pelos usuários focam na tentativa de se autoprotegerem principalmente dos episódios de violência e no alívio de sintomas desagradáveis causados pela droga - principalmente fissura e sintomas paranoides transitórios. Essas estratégias podem parecer efetivas a curto prazo, porém apresentaram riscos de longo prazo, tais como dependência de álcool e maconha.

Among long-term crack smokers, who avoids and who succumbs to cocaine addiction?

Crack cocaine is a highly addictive drug. To learn more about crack addiction, long-term crack smokers who had never met the DSM-IV criteria for lifetime cocaine dependence were compared with those who had. The study sample consisted of crack users (n=172) from the Dayton, Ohio, area who were interviewed periodically over 8 years. Data were collected on a range of variables including age of crack initiation, frequency of recent use, and lifetime cocaine dependence. Cocaine dependence was common with 62.8% of the sample having experienced it. There were no statistically significant differences between dependent and non-dependent users for age of crack initiation or frequency of crack use. In terms of sociodemographics, only race/ethnicity was significant, with proportionally fewer African-Americans than whites meeting the criteria for cocaine dependence. Controlling for sociodemographics, partial correlation analysis showed positive, statistically significant relationships between lifetime cocaine dependence and anti-social personality disorder, attention deficit/hyperactivity disorder, and lifetime dependence on alcohol, cannabis, amphetamine, sedative-hypnotics, and opioids. These results highlight the importance addressing race/ethnicity and comorbid disorders when developing, implementing, and evaluating interventions targeting people who use crack cocaine. Additional research is needed to better understand the role of race/ethnicity in the development of cocaine dependence resulting from crack use.