Patterns Of Cocaine Use Research Articles

MGlu5 inhibition in the basolateral amygdala prevents estrous cycle-dependent changes in cue-induced cocaine seeking

Drug associated cues are a common relapse trigger for individuals recovering from cocaine use disorder. Sex and ovarian hormones influence patterns of cocaine use and relapse vulnerability, with studies indicating that females show increased cue-induced craving and relapse vulnerability compared to males. In a rodent model of cocaine craving and relapse vulnerability, cue-induced cocaine seeking behavior following weeks of withdrawal from extended-access cocaine self-administration is higher in females in the estrus stage of the reproductive (estrous) cycle (Estrus Females) compared to both Males and females in all other stages (Non-Estrus Females). However, the neuronal substrates and cellular mechanisms underlying these sex differences is not fully understood. One region that contributes to both sex differences in behavioral responding and cue-induced cocaine seeking is the basolateral amygdala (BLA), while one receptor known to play a critical role in mediating cocaine seeking behavior is metabotropic glutamate receptor 5 (mGlu5). Here we assessed the effects of BLA mGlu5 inhibition following prolonged withdrawal from cocaine self-administration on observed estrous cycle-dependent changes in cue-induced cocaine seeking behavior. We found that BLA microinjections of the mGlu5 antagonist MTEP selectively reduced the enhanced cue-induced cocaine seeking normally observed in Estrus Females while having no effect on cocaine seeking in Males and Non-Estrus Females. These findings identify a unique interaction between cocaine-exposure, estrous cycle fluctuations and BLA mGlu5-dependent transmission on cue-induced cocaine seeking behavior.

Effects of Intermittent- vs Long-Access Cocaine Self-Administration on Addiction-Like Behaviors and NAc Glutamatergic Plasticity

Long Access self-administration procedures (LgA, 6hrs+/day) have become the gold-standard in the addiction field because they produce addiction-like behaviors, and changes in brain not seen following shorter drug access (1-2 hrs/day). However, Zimmer and colleagues recently developed an intermittent access self-administration procedure (IntA) to better model the patterns of cocaine use seen in addicts. IntA produces more robust addiction-like behaviors compared to LgA (cocaine-motivation, reinstatement, and cocaine-seeking) despite much less drug intake. Whether these distinct patterns of cocaine exposure produce similar or different alterations in nucleus accumbens (NAc) function is poorly understood, and there is limited understanding of the behavioral effects of IntA across sex.

Longitudinal changes in network engagement during cognitive control in cocaine use disorder

BackgroundCocaine use disorder (CUD) is characterized by poor cognitive control and has limited empirically supported treatment options. Furthermore, an understanding of brain mechanisms underlying CUD is at a relatively early stage. Thus, this study aimed to investigate longitudinal alterations in functional neural networks associated with cognitive control in cocaine use disorder (CUD). MethodsSecondary analysis was performed on data from 44 individuals who participated in three randomized clinical trials for CUD and completed an fMRI Stroop task both at baseline and post-treatment. Independent component analysis (ICA) was performed to assess changes in functional network engagement and investigate associations with cocaine-use behaviors. Mixed linear models were performed to test for longitudinal effects on network engagement and relationships with baseline patterns of cocaine use (i.e., past-month frequency and lifetime years of use) and periods of abstinence/use between scans (i.e., percent negative urine toxicology and maximum days of contiguous abstinence). ResultsSix functional networks were identified as being related to cognitive control and/or exhibiting changes in engagement following treatment. Results indicated that engagement of amygdala-striatal, middle frontal and right-frontoparietal networks were reduced over time in CUD. Less change in the amygdala-striatal network was associated with greater lifetime years of cocaine use. Additional analyses revealed that negative toxicology results and achievement of continuous abstinence were associated with greater engagement of the right-frontoparietal network. ConclusionsNeural systems that underlie cognitive control may change over time in individuals with CUD. A longer history of cocaine-use may hinder changes in network activity, potentially impeding recovery.

Hair Testing for Classic Drugs of Abuse to Monitor Cocaine Use Disorder in Patients Following Transcranial Magnetic Stimulation Protocol Treatment.

Simple SummaryHair testing for classic drugs of abuse offers the possibility of longer detection times (for drug substances) when compared to urine analysis. Hair analysis is routinely used to detect drug abuse in forensic cases and clinical toxicology, whereas it is rarely used at addiction clinics to monitor the clinical efficacy of therapeutic interventions. Here, we explore for the first time whether hair analysis might represent a valid tool to track the clinical improvements in a population of patients with cocaine use disorder (CocUD) who underwent a repetitive transcranial magnetic stimulation (rTMS) treatment.In recent years, hair has become an alternative biological specimen for drug testing in the fields of forensic and clinical toxicology. The advantages of hair testing include larger detection windows (months/years), depending on the length of the hair shaft, compared to those of urine/blood (hours to 2–4 days for most drugs). Segmental hair analysis can disclose a month-to-month (considering 1 cm segment cuts) information of drug exposure (single or repeated) and potentially identify patterns of drug use/administration. Repetitive transcranial magnetic stimulation (rTMS) was recently proposed as a valid tool for therapeutic purposes in addictions, including cocaine use disorder (CocUD). Here, we proposed hair testing analyses of classic drugs of abuse in a clinical setting to monitor the clinical changes in treatment-seeker CocUD patients undergoing protocol treatments with rTMS stimulating the left dorsolateral prefrontal cortex (l-DLPFC). We collected hair samples from nine CocUD patients at different stages from the beginning of treatments. Hair sample analyses revealed significant changes in the patterns of cocaine use, according to the negativity of urine screening tests and the clinical reductions of craving. These data, albeit preliminary, suggest that hair testing analysis of classic drugs of abuse could be extended to clinical settings to monitor the clinical efficacy of innovative therapeutic interventions, such as rTMS.

Cocaine and Marijuana Polysubstance Use and Cocaine Use Disorder: Investigating Mediated Effects through Patterns of Cocaine Use

Objectives Cocaine use is on the rise and it is comorbid with marijuana use. We examined the association between lifetime cocaine + marijuana polysubstance use (CM PSU) versus cocaine only and lifetime cocaine use disorder (CocUD) and examined the potential mediation by cocaine use patterns. Methods: A total of 2,968 lifetime cocaine users were identified from the National Epidemiologic Survey on Alcohol and Related Conditions-III. Mediation analysis was utilized to examine cocaine use quantity, frequency, and duration as potential mediators in the association between CM PSU and CocUD. A parallel multiple mediator model and a structural equation model were used, respectively, to examine: (1) the individual contribution of cocaine use quantity, frequency, and duration, and (2) combined contribution as a set specified by a latent variable. Results: Cocaine users were divided into 2,782 (93.7%) CM polysubstance users and 186 (6.3%) cocaine only users. CM PSU was associated with decreased risk of CocUD, but after including the mediators, the association was no longer significant. Examined separately, only quantity was found to be a significant mediator over and above frequency and duration, while the latent variable with three cocaine use pattern indicators explained 56.6% of the total association between CM PSU and CocUD. Conclusions: Compared to cocaine only users, CM polysubstance users were less likely to use cocaine heavily; this lower intensity of cocaine use was in turn associated with decreased risk of CocUD. Future research is warranted to determine the nature of the association between CM PSU and reduced CocUD.

Longitudinal patterns of cocaine use among patients receiving injectable hydromorphone or diacetylmorphine for the treatment of opioid use disorder: A growth curve modeling approach

Background and aimsCocaine use is prevalent among people receiving injectable opioid agonist treatment. Investigations of cocaine use in this population have been descriptive and the potential heterogeneity existing in patterns of use have not been characterized. As such, among patients receiving injectable opioid agonist treatment, this study aimed to: 1) quantify intra- and inter-individual variation in cocaine use over 24-months and; 2) determine how predictors of interest explained this variation. MethodsParticipants were patients receiving injectable opioid agonist treatment for opioid use disorder. Study visits were completed at baseline prior to receiving treatment, and 3,6,9,12,18, and 24 months after baseline. A multi-level regression approach to growth curve modeling was employed to estimate and explain intra- (within-person) and inter-individual (between-person) variation in cocaine use. ResultsSignificant intra and inter-individual variation in cocaine use was identified over 24-months. Treatment engagement was on average associated with reductions in the prior month number of days of cocaine use (range: 0–30)(Estimate (standard error): -0.05(0.02), p = 0.003). On average, men reported less cocaine use compared to women (Estimate (standard error): -5.91(1.57), p=<0.001), and participants reporting ever regularly using cocaine at baseline reported more cocaine use over 24-months compared to participants reporting never regularly using cocaine (Estimate (standard error): 4.72 (1.91), p = 0.013). ConclusionsSignificant reductions in cocaine use were observed and significant heterogeneity in patterns of cocaine use was identified. These heterogeneous cocaine use profiles suggest that an individualized approach to care will be critical in responding to patients’ cocaine use in injectable opioid agonist treatment.

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

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. 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. 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. 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.

Between Careers, Networks and LGBT Circuits – An Ethnographic Approach to the Styles and Patterns of Cocaine use in São Paulo

Between Careers, Networks and LGBT Circuits – An Ethnographic Approach to the Styles and Patterns of Cocaine use in São Paulo

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

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

Between the lines, networks and lgbtq+ circuits – an ethnographic approach to the styles and patterns of cocaine use in São Paulo/Brazil

This article is the result of long years of ethnographic research in the city of São Paulo with cocaine users in different territories and circuits, especially LGBTQ+ consumers in the central region of the state capital. The research was constructed with direct observations and with the employment of interviewed with 11 “key informants”", who narrates about their own consumption and the users of their networks of friendships, which they knew better in two different moments in 1994 and 2006. It makes a brief critical commentary on the “state of the art” in this field of study, with particular attention to the production of the social sciences. This research seeks to understand the learning about the use of illicit drugs (cocaine), the forms of user control, the rituals and patterns of use, as well as the life trajectories of cocaine users. Finally, it shows the role played by cocaine in different socio-cultural contexts, particularly the use of cocaine in sexual and homoerotic contexts.

Sex differences in incentive-sensitization produced by intermittent access cocaine self-administration

Intermittent Access (IntA) cocaine self-administration, which models intermittent patterns of cocaine use in humans during the transition to addiction, is especially effective in producing incentive-sensitization and other addiction-like behavior in male rats. However, female rats show more robust psychomotor sensitization than males, and following initial use, women develop problematic patterns of drug use more readily than men. We hypothesized, therefore, that female rats might be more susceptible to the incentive-sensitization produced by IntA experience. To assess changes in motivation for cocaine, using a behavioral economic indicator of cocaine demand ("elasticity" of demand curves), and other addiction-like behavior, as a function of IntA cocaine self-administration experience in male and female rats. IntA experience produced a progressive increase in motivation for cocaine in both males and females, as indicated by a decrease in the elasticity of cocaine demand curves, and this persisted undiminished following 14days of abstinence. However, IntA produced a more rapid and greater increase in motivation for cocaine (incentive-sensitization) in females than males. Females also consumed more cocaine than males, although this did not predict changes in motivation. On the other hand, there were no sex differences in the preferred level of cocaine consumption when cost was low (Q0), nor in cocaine- or cue-induced reinstatement of drug-seeking behavior. The observation that females are more susceptible to incentive-sensitization when intermittently exposed to cocaine may provide a mechanism for the more rapid development of problematic drug use in females ("telescoping effect") reported in clinical studies.

The limited impact that cocaine use patterns have on neurocognitive functioning in individuals with cocaine use disorder

It is well-documented in the literature that cocaine use is associated with neurocognitive impairment. The manner in which patterns of cocaine use, such as years of use, recent use over the past month, and daily amount of cocaine use, moderate neurocognition has been studied in a relatively piecemeal manner. Hence, the purpose of the study was to evaluate whether cocaine use patterns modulate neurocognition in individuals with cocaine use disorder. Cocaine users who were cocaine-negative ( n=125) were divided into tertiles based on cocaine use patterns and the performances of the highest and lowest groups were compared on the following cognitive measures: Continuous Performance Task-II, n-back, and Hopkins Verbal Learning Task-Revised. Participants with cocaine use disorder who used for more years (25.2±0.6 versus 10.1±0.6 years; mean±standard error of the mean) and who had more recent cocaine use over the past month (26.3±0.5 versus 6.0±0.6 days) did not differ significantly on any of the neurocognitive variables when compared to those with use patterns of shorter duration and less frequency (all p's >0.05). Lastly, participants reporting the greatest amount daily cocaine use (1.8±0.0 g) demonstrated better performance on an auditory working memory task when compared to those with the lowest daily use (0.7±0.0 g; p=0.04). While one might expect that individuals who used greater amounts of cocaine over longer periods of time would demonstrate relatively poorer performance on measures of neurocognition, particularly in the initial phase of abstinence, our findings did not confirm this. While speculative, a potential explanation for these findings is that after an individual uses cocaine for a certain number of years, or uses a specific amount over time, then the deleterious effects of cocaine on neurocognition stabilizes, and increased duration of cocaine use does not further exacerbate those impairments.

The Effects of Excitatory and Inhibitory Social Cues on Cocaine-Seeking Behavior.

Social partners influence the likelihood of using drugs, developing a substance use disorder and relapse to drug use after a period of abstinence. Preclinical studies report that social cues influence the acquisition of cocaine use, the escalation of cocaine use over time, and the compulsive patterns of cocaine use that emerge during an extended binge. The purpose of this study was to examine the effects of social cues on the reinstatement of cocaine-seeking behavior after a period of abstinence. Male rats were obtained at weaning, assigned to triads (three rats/cage), reared to adulthood and implanted with intravenous catheters. Rats from each triad were then assigned to one of three conditions: (1) test rats were trained to self-administer cocaine and were tested for reinstatement; (2) cocaine partners were trained to self-administer cocaine and were predictive of response-contingent cocaine delivery; and (3) abstinent partners were not given access to cocaine and were predictive of extinction. The test rats alternated social partners every 5 days for 20 days such that responding was reinforced with cocaine in the presence of the cocaine partner (S+) for 10 days and not reinforced with cocaine in the presence of the abstinent partner (S−) for 10 days. Responding of the test rats was then extinguished over 7 days under isolated conditions. Tests of reinstatement were then conducted in the presence of the cocaine partner and abstinent partner under extinction conditions. Neither social partner reinstated responding relative to that observed on the final day of extinction; however, responding was greater in the presence of the cocaine partner (S+) than the abstinent partner (S−) during the reinstatement test. These data fail to demonstrate that a social partner reinstates cocaine-seeking behavior after a period of abstinence, but they do indicate that social partners can serve as either excitatory or inhibitory discriminative stimuli to influence drug-seeking responses.

Methadone maintenance therapy and viral suppression among HIV-infected opioid users: The impacts of crack and injection cocaine use

BackgroundMethadone maintenance therapy (MMT) is associated with improved HIV treatment outcomes among people who use drugs (PWUD). The extent to which these benefits are sustained in the context of ongoing cocaine use is unclear. We assessed differential impacts of MMT on HIV viral load (VL) suppression in relation to discrete patterns of cocaine use. MethodsData was drawn from ACCESS, a prospective cohort of HIV-positive PWUD in Vancouver, Canada. Generalized linear mixed-effects were used to model the independent effect of MMT on VL suppression across strata of frequency of cocaine injection and crack smoking (≥daily versus <daily), after adjustment for confounders. ResultsThe analysis included 397 HIV-positive opioid users who completed ≥1 study interview between 2005 and 2014. At baseline, 304 (77%) reported participation in MMT, 37 (9%) ≥daily cocaine injection, and 158 (40%) ≥daily crack smoking. In adjusted analyses, MMT remained independently associated with increased odds of VL suppression in both strata of crack smokers (AOR=3.11, 95% CI: 1.86–5.21 and AOR=1.48, 95%CI: 1.04–2.09, for ≥daily and <daily smokers, respectively), and among <daily cocaine injectors (AOR=1.88, 95%CI 1.38–2.56), but not among ≥daily cocaine injectors (AOR=1.37, 95%CI 0.53–3.49). Longer retention on MMT was positively associated with VL suppression in all strata of cocaine injection and crack smoke. ConclusionsExposure to MMT was associated with increased odds of VL suppression among HIV- positive opioid users regardless of crack use. However, this beneficial effect of MMT was lost among frequent cocaine injectors with shorter retention on MMT.

Predicting Outcome in Public Addiction Services Using Data Collected During Routinely Assessment Procedures

The study examined the ability of several baseline variables to predict retention and treatment outcome in a cohort study that included 137 participants with heroin and cocaine addiction attending a public addiction service in Italy. Predictors included past drug use, intravenous use, initial urine drug screen results, cocaine and heroin craving and self-reported psychiatric symptoms. Severe depression and, in a lesser extent, anxiety symptoms, predicted lower retention. Only intravenous use was a significant predictor of cocaine use in the whole sample. Positive urine for cocaine and intravenous use predicted worse outcome among heroin addicts. Three Symptoms Checklist-90 (SCL-90) scales scores were associated with lower cocaine and heroin use. Multiple logistic regression showed that cocaine positivity and more structured psychosocial treatment predicted successful outcome. Results highlight the prognostic value of carefully assessing patterns of cocaine use and co-use, routes of administration and psychiatric symptoms at the beginning of treatment, especially in heroin addicts.

Cocaine users and self-regulation mechanisms

Purpose – The prevalence of cocaine use has been increasing since the mid-1990s in many European countries, Italy included. There is a large variety of patterns of cocaine use in natural settings, but on the whole, the existence of different patterns of cocaine use remains widely unknown to drug professionals, as well as to public opinion. The purpose of this paper is to investigate patterns and trajectories of use, the meaning of use within the context of users’ life styles, the perception of controlled/uncontrolled use, personal strategies to keep drug use “under control”. Design/methodology/approach – This paper illustrates findings from a qualitative study among 115 cocaine users. Participants were recruited using the snow ball sampling (a minimum lifetime experience of 20 instances of cocaine use was required). Findings – The findings confirm the variability of cocaine use trajectories and the prevalent tendency towards more moderate patterns of use. Such variability is in patent contrast to the disease model of addiction and its assumed predetermined linear trajectories. Set, and particularly setting and all the environmental factors, such as life events, appear to be the variables that can better explain the dynamic course of patterns of use. Research limitations/implications – The main limit concerns the non-randomisation in the selection of the nominees. Participants were recruited in the night entertainment scene of the main Tuscan cities through personal contacts of staff from risk reduction facilities: in spite of the personal and confidential approach, the number of “non institutionalized” users willing to collaborate was too low, therefore the authors decided to omit the randomisation. Social implications – The findings bear social implications as they can contribute to a change in the social representation of users so as to reduce the stigma. They can also prompt innovation in the operational models of drug services. Originality/value – It is the first qualitative research from the “control” perspective ever led in Italy.

Powder and crack cocaine use among opioid users: is all cocaine the same?

Problematic cocaine use is highly prevalent and is a significant public health concern. However, few investigations have distinguished between the 2 formulations of cocaine (ie, powder and crack cocaine) when examining the characteristics of cocaine use. Moreover, research has yet to assess the patterns of powder and crack cocaine use among opioid users, a clinical population in which problematic cocaine use is increasingly common. Using a within-subjects design, this study examined whether opioid users reported different patterns and features of powder and crack cocaine use, along with distinct trajectories and consequences of use. Seventy-three clients enrolled in a low-threshold methadone maintenance treatment were interviewed regarding their lifetime use of powder and crack cocaine. Compared with crack cocaine, initiation and peak use of powder cocaine occurred at a significantly younger age. In relation to recent cocaine use, participants were significantly more likely to report using crack cocaine than using powder cocaine. Differences in routes of administration, polysubstance use, and criminal activity associated with cocaine use were also found between the 2 forms of cocaine. Results suggest that it may not be appropriate to consider powder and crack cocaine as diagnostically and clinically equivalent. As such, researchers may wish to distinguish explicitly between powder and crack cocaine when assessing the characteristics and patterns of cocaine use among substance users and treat these 2 forms of cocaine separately in analyses.

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

To determine predictors of changes in amount of cocaine use among regular users outside treatment services. 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). Three Spanish cities: Barcelona, Madrid and Seville 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. 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. 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. 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.

Patterns and Predictors of Changes in Substance Use in Individuals With Schizophrenia and Affective Disorders

Objective: This study examined patterns and predictors of changes in substance use over 1 year in individuals with schizophrenia and affective disorders. We examined patterns of cocaine use over time, baseline predictors of continued cocaine use over 1 year, and predictors of transitions into and out of drug use and treatment. Methods: We recruited 240 individuals with schizophrenia and affective disorders who met DSM-IV criteria for current cocaine dependence or cocaine dependence in early full or sustained full remission and assessed them five times over 12 months. Results: There was no change over time in either the proportion of the sample with at least 1 day of cocaine use in the past month or in the average number of days of cocaine use among those who reported any use. Baseline variables assessing actual substance use were found to predict a decreased likelihood of cocaine use. Several such variables—including self-reported use of cocaine, positive urinalysis results for marijuana, and positive urinalysis results for cocaine—were predictive of transitions into and out of outpatient substance abuse treatment. Readiness to change variables such as self-efficacy and temptation to use drugs showed different predictive patterns for the schizophrenia and affective disorder groups. Conclusions: These findings illustrate how drug use may show a cyclical pattern for those with serious mental illness, in which more severe use—characterized by greater frequency of use and associated problems—is followed by decreased use over time.

Cocaine use trajectories of club drug-using young adults recruited using time-space sampling

Cocaine is the most widely used club drug. Yet, little is known about how patterns of cocaine use vary over time among young adults of diverse gender and sexual identities. This study used latent class growth analysis to identify trajectories of cocaine use over a year and explored individual and substance use factors associated with these trajectories. A sample of 400 young adults (mean age = 23.9 years) with recent club drug use were recruited from New York City bars and nightclubs using time-space sampling. Participants completed quantitative measures at baseline, 4-, 8- and 12-months follow-up. A 4-class model fit the data best. Patterns were: Consistent use (48%), Inconsistent use (14%), Decreasing Likelihood of use (28%), and Consistent non-use (11%). Those most likely to be in the Consistent use class had the highest frequency of baseline club drug dependence ( χ 2 (3, 397) = 15.1, p < .01), cocaine dependence ( χ 2 (3, 397) = 18.9, p < .01), recent alcohol use ( χ 2 (3, 397) = 12.48, p < .01), and drug sensation-seeking ( χ 2 (3, 397) = 9.03, p < .01). Those most likely to be in the Consistent Non-use class had the highest frequency of baseline marijuana use ( χ 2 (3, 397) = 2.71, p < .05). Contrary to hypotheses, there were no differences in most-likely trajectory class by gender/sexual-orientation, age, ethnicity, education, employment status, or income. Findings highlight the diversity of cocaine use patterns over time among young adults, and the personal and substance use characteristics that are associated with each.