Violence among men and women in substance use disorder treatment: A multi-level event-based analysis

Background

This study examined associations between acute alcohol and drug use and violence towards others in conflict incidents (overall, partner, and non-partner conflict incidents) by men and women recruited from substance use disorder (SUD) treatment.

Methods

Semi-structured interviews were used to obtain details about interpersonal conflict incidents (substance use, whether specific conflicts were with intimate partners or non-partners) in the 180 days pre-treatment. Participants for this study were selected for screening positive for past-year violence (N = 160; 77% men, 23% women).

Results

Multi-level multinomial regression models showed that after adjusting for clustering within individual participants, the most consistent predictors of violence across models were acute cocaine use (significant for overall, intimate partner and non-partner models), acute heavy alcohol use (significant for overall and non-partner models), and male gender (significant in all models).

Conclusions

This study was the first to explicitly examine the role of acute alcohol and drug use across overall, partner and non-partner conflict incidents. Consistent with prior studies using a variety of methodologies, alcohol, cocaine use and male gender was most consistently and positively related to violence severity (e.g., resulting in injury). The results provide important and novel event-level information regarding the relationship between acute alcohol and specific drug use and the severity of violence in interpersonal conflict incidents.     

Telehealth-delivered group smoking cessation for rural and urban participants: feasibility and cessation rates

Background

Large-group behavioral smoking cessation interventions are effective for helping people quit smoking, but have not been evaluated using videoconferencing technology for rural and remote participants who have no access to in-person cessation programs. The objectives of this study were to provide and evaluate an evidence-based group smoking cessation program for rural/remote smokers wishing to quit through a Telehealth videoconferencing link at their local Health Centre.

Methods

From September 2005 through April 2008, eight separate eight-session, 4 month long smoking cessation group programs were offered both in person to urban participants in Calgary and at up to six rural sites simultaneously via Telehealth videoconferencing. Quit rates were assessed at program completion, 6 and 12 month follow-up. Participants also provided evaluations of the program and technology.

Results

554 smokers participated in the program: 370 in Calgary and 184 at various remote sites. Sixteen Telehealth sites participated from across Alberta and one site from the Northwest Territories. After program completion, continuous abstinence rates using the most conservative intent-to-treat method were 27.5% in Calgary and 25.5% for the rural Telehealth sites. Quit numbers were much higher using only Available Data at 39.2% for Calgary and 37.2% for the rural sites. Similar rates were maintained over the 12-month follow-up. Program evaluations were positive.

Conclusions

It is possible to offer effective smoking cessation to small groups of patients in rural or remote locations through Telehealth videoconferencing technology, which produces quit rates similar to in-person groups.     

Psychosocial treatments for cocaine dependence: the role of depressive symptoms

Background

The association between cocaine use and depression has been frequently observed. However, less is known about the significance of depression in the treatment of cocaine use disorders. This study examined possible interrelations between drug use and depression severity among cocaine-dependent patients in psychosocial treatments for cocaine dependence.

Methods

Monthly assessed drug use and depression severity scores of N = 487 patients during 6-month psychosocial treatments for cocaine dependence were analyzed using hybrid latent growth models.

Results

Results indicated a moderate but statistically significant (z = 3.13, p < .01) influence of depression severity on increased drug use in the upcoming month, whereas drug use did not affect future depression severity.

Conclusions

Findings suggest that depression symptoms are an important predictor of drug use outcomes during psychosocial treatments for cocaine dependence and, hence, underline the importance of adequately addressing depression symptoms to improve treatment outcomes.     

Effects of the selective sigma receptor ligand, 1-(2-phenethyl)piperidine oxalate (AC927), on the behavioral and toxic effects of cocaine

Background

Sigma receptors represent a unique structural class of proteins and they have become increasingly studied as viable medication development targets for neurological and psychiatric disorders, including drug abuse. Earlier studies have shown that cocaine and many other abused substances interact with sigma receptors and that antagonism of these proteins can mitigate their actions.

Methods

In the present study, AC927 (1-(2-phenethyl)piperidine oxalate), a selective sigma receptor ligand, was tested against the behavioral and toxic effects of cocaine in laboratory animals.

Results

Acute administration of AC927 in male, Swiss Webster mice significantly attenuated cocaine-induced convulsions, lethality, and locomotor activity, at doses that alone had no significant effects on behavior. Subchronic administration of AC927 also attenuated cocaine-induced conditioned place preference in mice, at doses that alone had no effects on place conditioning. In drug discrimination studies in male, Sprague-Dawley rats, AC927 partially substituted for the discriminative stimulus effects of cocaine. When it was administered with cocaine, AC927 shifted the cocaine dose-response curve to the left, suggesting an enhancement of the discriminative stimulus effects of cocaine. In non-human primates, AC927 was self-administered, maintaining responding that was intermediate between contingent saline and a maintenance dose of cocaine.

Conclusion

The ability of AC927 to elicit some cocaine-like appetitive properties and to also reduce many cocaine-induced behaviors suggests that it is a promising lead for the development of a medication to treat cocaine abuse.     

How drug policy should (not) be: institutionalised young people's perspectives

Background

Drug prevention is insufficiently tailored to the needs of vulnerable groups and often concentrates on the general population.

Methods

A qualitative youth-centred design, based on group techniques was used to ask vulnerable young people about their needs and expectations regarding drug prevention practices. Participants comprised 160 young people, aged 12-21 years who had emotional and behavioural disorders and who lived in institutions in the mental health care system in Flanders.

Results

Findings showed that common prevention and education practices are often insufficient or not applicable to the participants’ situation. The young people criticised the institutions’ reaction to drug use because it tried to control and sanction their use and paid scant attention to their reasons for drug use. They also held negative views about drug treatment. Their experiences had taught them that control and sanctioning were the dominant reactions to drug use.

Conclusion

If drug (prevention) policy is to appeal to vulnerable young people, their views on what would make a good prevention policy must be taken into account.     

Initiation and persistence of alcohol use in United States Black, Hispanic, and White male and female youth

Background

The relation between early and frequent alcohol use and later difficulties is quite strong. However, the degree that alcohol use persists, which is often a necessary cause for developing alcohol-related problems or an alcohol use disorder, is not well studied, particularly with attention to race and gender. A novel statistical approach, the Multi-facet Longitudinal Model, enables the concurrent study of age of initiation and persistence.

Methods

The models were applied to longitudinal data on youth alcohol use from ages 12 through 19, collected in the (U.S.) National Longitudinal Survey of Youth 1997 cohort (N = 8984).

Results

Results confirmed that Black adolescents initiate alcohol use at later ages than do White youth. Further, after initiation, White adolescents were substantially more likely than Black adolescents to continue reporting alcohol use in subsequent years. Hispanic teens showed an intermediate pattern. Gender differences were more ambiguous, with a tendency for boys to be less likely to continue drinking after initiation than were girls.

Conclusions

Novel findings from the new analytic models suggest differential implications of early alcohol use by race and gender. Early use of alcohol might be less consequential for males who initiate alcohol use early, Black, and Hispanic youth than for their female and White counterparts.     

Evaluation of the hydrolytic activity of a long-acting mutant bacterial cocaine in the presence of commonly co-administered drugs

Background

Cocaine toxicity is a prevalent problem in the Unites States for which there is currently no FDA-approved pharmacotherapy. We have developed a bacterial cocaine esterase (CocE) towards this indication. A thermostabilized mutant of CocE (DM-CocE) retains the hydrolytic activity of the wild-type esterase, rapidly hydrolyzing cocaine into the inactive metabolites ecgonine methyl ester and benzoic acid, and can prevent cocaine toxicities in rodent and non-human primate models. To advance DM-CocE towards clinical use, we examine here how the hydrolytic activity of DM-CocE is altered by some drugs commonly co-administered with cocaine.

Methods

We employed a spectrophotometric cocaine hydrolysis assay to evaluate whether pharmacologically relevant doses of alcohol, nicotine, morphine, phencyclidine, ketamine, methamphetamine, naltrexone, naloxone, or midazolam would alter the Michaelis-Menten kinetics of DM-CocE for cocaine. Mass spectrometry was used to evaluate interaction with diazepam as this drug interferes with the absorbance spectra of cocaine critical for the spectrophotometric assay.

Results

Alcohol, nicotine, morphine, phencyclidine, ketamine, methamphetamine, naltrexone, naloxone, and midazolam did not alter cocaine hydrolysis by DM-CocE. However, diazepam significantly slowed DM-CocE cocaine hydrolysis at very high concentrations, most likely through interaction of the phenyl ring of the benzodiazepine with the active site of DM-CocE.

Conclusions

DM-CocE does not display significant drug interactions, with the exception of diazepam, which may warrant further study as DM-CocE progresses towards a clinically used pharmacotherapy for cocaine toxicity. Alternate benzodiazepines, e.g., midazolam could be used to avoid this potential interaction.     

Regulation of cocaine self-administration in humans: Lack of evidence for loading and maintenance phases

Background

In rodents, cocaine self-administration under a fixed-ratio schedule and with timeout intervals limited to the duration of the infusions is characterized by an initial burst of drug intake (loading) followed by more stable infusion rates (maintenance). We sought to examine whether similar phases might characterize self-regulated cocaine use in humans.

Methods

31 Non-treatment seeking, cocaine dependent subjects participated in three (8, 16, and 32 mg/70 kg/infusion), self-regulated, 2-h cocaine self-administration sessions under a fixed-ratio 1, 5-min timeout schedule. Data were assessed for visual (e.g., by graphs of cumulative numbers of infusions) and statistical evidence of change in phase (by step-function analyses of individual infusion rates).

Results

Graphs of cumulative infusions over time suggested a single, linear rate of self-administration over 2 h at each cocaine dose. Statistical analyses of infusion data by generalized estimating equation (GEE) models also failed to support a loading/maintenance pattern (suggesting, if anything, the possibility of increasing infusion rates over time).

Conclusions

Our findings fail to support the existence of distinct loading and maintenance phases of self-regulated cocaine administration in humans at behaviorally relevant doses. Several factors may account for these observations including differences between humans and rodents in self-regulated drug intake.     

The transition to harm reduction: understanding the role of non-governmental organisations in Malaysia

Background

The transition of drug policy from prohibition to harm reduction has never been easy. The deeply entrenched belief in prohibition shared by policy makers and religious leaders provided little room for alternatives, and change came only slowly. The non-governmental organisations (NGOs) in Malaysia played a pivotal role in effecting such a change. Understanding how they did so may be instructive for other similarly placed countries.

Methods

Data collected via reviews of published secondary sources, media reports and in-depth interviews with pioneers of harm reduction drawn from NGOs, medical practitioners and the police were analysed to construct the paper.

Results

The policy change was the outcome of competition between three groups in the drug policy subsystem - the state, the Muslim religious lobby and the NGOs. Developments such as the poor outcomes from the prohibition programmes and the outbreak of HIV/AIDS did not change policy but did lead to a rethink of core beliefs in the state alliance and spawned a state-NGO partnership. The subsequent failure to meet the Millennium Development Goal with respect to HIV/AIDS in 2005 - was seen as a failure of the Health Ministry which then led the final charge for a policy change arguing that a health crisis was imminent. The NGOs played a pivotal role in this process by educating their partners in the state coalition, by drawing academics and medical practitioners into advocacy and by engaging the religious lobby (albeit with varying success). They were also frontline players in implementing harm reduction programmes and successfully deflected criticisms from unconvinced Islamic groups away from the state.

Conclusion

Given their central role in the needle-syringe exchange programme, the NGOs are well positioned to convince injecting drug users to opt for voluntary medical treatment. This can potentially reduce both the harm from drug use and the prevalence of it.     

Internet-based group contingency management to promote abstinence from cigarette smoking: a feasibility study

Background

In contingency management (CM) interventions, monetary consequences are contingent on evidence of drug abstinence. Typically, these consequences are contingent on individual performance. Consequences contingent on group performance may promote social support (e.g., praise).

Methods

Thus, to combine social support with the monetary incentives of CM, we integrated independent and interdependent group contingencies of reinforcement into an Internet-based intervention to promote smoking abstinence. Breath carbon monoxide (CO) measures were compared between treatment conditions and a baseline control condition. Thirteen participants were divided into 5 groups or “teams” (n = 2-3 per team). Each participant submitted video recordings of CO measurement twice daily via the Internet. Teammates could monitor each other's progress and communicate with one another through an online peer support forum. During a 4-day tapering condition, vouchers exchangeable for goods were contingent on gradual reductions in breath CO. During a 10-day abstinence induction condition, vouchers were contingent on abstinence (CO ≤ 4 ppm). In both treatment conditions, concurrent independent and interdependent group contingencies were arranged (i.e., a mixed contingency arrangement).

Results

Less than 1% of CO samples submitted during baseline were ≤ 4 ppm, compared to 57% submitted during abstinence induction. Sixty-five percent of participants’ comments on the online peer support forum were rated as positive by independent observers. Participants rated the intervention favorably on a treatment acceptability questionnaire.

Conclusion

The results suggest that the intervention is feasible and acceptable for promoting abstinence from cigarette smoking.     

Prenatal exposure to bisphenol A and phthalates and infant neurobehavior

Objective

To examine the association of prenatal exposure to bisphenol A and select common phthalates with infant neurobehavior measured at 5 weeks.

Methods

We compared the concentration of maternal urinary metabolites of bisphenol A and phthalates at two distinct time points in pregnancy (16w, 26w) with scores on the NICU Network Neurobehavioral Scale (NNNS) at 5 weeks of age in a cohort of 350 mother/infant pairs.

Results

Prenatal exposure to BPA was not significantly associated with neurobehavioral outcomes at 5 weeks. Significant associations between prenatal exposure to measured phthalates and infant neurobehavioral outcomes differed by type of phthalate and were only seen with exposure measured at 26 weeks. Higher total di-butyl phthalate (DBP) metabolites at 26w were associated with improved behavioral organization evidenced by decreased arousal (p = .04), increased self-regulation (p = .052), and decreased handling (p = .02). In males, higher total di-2-ethylhexyl phthalate (DEHP) metabolites at 26w were associated with more nonoptimal reflexes (p = .02).

Conclusion

The association between prenatal phthalate exposure and infant neurobehavior differed by type of phthalate and was evident only with exposure measured at 26w. Prenatal exposure to DBP was associated with improved behavioral organization in 5-week-old infants. Prenatal exposure to DEHP was associated with nonoptimal reflexes in male infants. There was no evidence of an association between prenatal BPA exposure and infant neurobehavior.     

5-HT induces temporomandibular joint nociception in rats through the local release of inflammatory mediators and activation of local β adrenoceptors

Objectives

The present studies assessed the effects of adolescent and adult ethanol exposure on the rewarding effects of cocaine as measured with the conditioned place preference procedure.

Methods

Male rats were exposed to intraperitoneal (IP) injections of ethanol or vehicle for 10 days [postnatal days (PNDs) 30-39 or PNDs 70-79; 2 mg/kg]. Place preference conditioning began on PND 65 or PND 105, respectively, and consisted of a baseline test followed by four conditioning cycles with either 0, 5, 10 or 20 mg/kg cocaine. Following the fourth conditioning cycle a final preference test was performed. Changes in time on the drug-paired side between the baseline and final test were analyzed.

Results

Animals exposed to vehicle (during adolescence or adulthood) showed a significant place preference at 20 mg/kg cocaine. Animals exposed to ethanol (during adolescence or adulthood) showed a significant place preference at 10 mg/kg cocaine.

Conclusions

Exposure to ethanol (adolescents or adults) sensitized the rewarding effects of cocaine. This may indicate an increase in the abuse liability of cocaine following a history of ethanol exposure.     

Markers of abuse liability of short- vs long-acting opioids in chronic pain patients: A randomized cross-over trial

Background

Abuse liability is thought to possibly be lower in long- than in short-acting opioids because lower peak serum levels may be less likely to induce psychoactive effects.

Methods

We compared patient responses to extended-release morphine, hydrocodone plus acetaminophen, and placebo in a randomized, double-blind crossover study using markers of abuse liability. Patients indicated their craving for drugs on 5 visual analog scales (VASs), completed the Addiction Research Center Inventory, and underwent cue reactivity testing. To perform the latter, subjects watched a video intended to produce a positive or a negative affect, after which a vial of medication was or was not presented (the cue) and then indicated their craving for drugs on 5 different VASs (the reactivity).

Results

Differences in Addiction Research Inventory scores were statistically significant but clinically unimportant. Neuropsychological test results were mixed and unrelated to the medications studied. Cue reactivity did not differ among conditions but was uniformly high.

Conclusions

Using several markers of abuse liability, long-acting opioids do not have lower abuse potential than do short-acting opioids or placebo. Although cue reactivity did not differ among the conditions, uniformly high results in these patients suggest that it may have some value as a component of abuse liability testing.     

Concurrent heroin use among methadone maintenance clients in China

Background

The study examined concurrent illicit heroin use among methadone maintenance clients in China and its association with clients' demographic characteristics, treatment experience, and personal social network.

Methods

Face-to-face surveys were conducted with 178 clients randomly recruited from six methadone maintenance treatment (MMT) clinics in Sichuan, China. Concurrent heroin use was measured based on self-report of heroin use during the past 30 days and a confirmatory urine morphine test. The participants' demographic characteristics and treatment factors were measured and examined. The drug use status of their family members and friends was also assessed.

Results

A total of 80 participants (44.9%) who either reported illicit heroin use in the past 30 days or had a positive urine test were defined as using heroin concurrently. Having drug-using friends was significantly associated with increased concurrent heroin use. Longer length of treatment (2 years or longer) was associated with increased concurrent heroin use. Among those who had both drug-using family members and friends, more women (71.4%) than men (50.0%) used heroin. For those who had no drug-using family members or friends, more men (34.8%) than women (20.8%) used heroin.

Discussion

Study findings indicate an urgent need to address concurrent illicit heroin use among MMT clients. Further examination of the influence of social networks on concurrent drug abuse behavior is encouraged. Results also highlight the importance of understanding gender differences in treatment seeking and behavioral changes, which is crucial to the development of gender-specific treatment strategies.     

Early adolescent cocaine use as determined by hair analysis in a prenatal cocaine exposure cohort

Background

Preclinical and other research suggest that youth with prenatal cocaine exposure (PCE) may be at high risk for cocaine use due to both altered brain development and exposure to unhealthy environments.

Methods

Participants are early adolescents who were prospectively enrolled in a longitudinal study of PCE prior to or at birth. Hair samples were collected from the youth at ages 10½ and 12½ (N = 263). Samples were analyzed for cocaine and its metabolites using ELISA screening with gas chromatography/mass spectroscopy (GC/MS) confirmation of positive samples. Statistical analyses included comparisons between the hair-positive and hair-negative groups on risk and protective factors chosen a priori as well as hierarchical logistical regression analyses to predict membership in the hair-positive group.

Results

Hair samples were positive for cocaine use for 14% (n = 36) of the tested cohort. Exactly half of the hair-positive preteens had a history of PCE. Group comparisons revealed that hair-negative youth had significantly higher IQ scores at age 10½; the hair-positive youth had greater availability of cigarettes, alcohol, and other drugs in the home; caregivers with more alcohol problems and depressive symptoms; less nurturing home environments; and less positive attachment to their primary caregivers and peers. The caregivers of the hair-positive preteens reported that the youth displayed more externalizing and social problems, and the hair-positive youth endorsed more experimentation with cigarettes, alcohol, and/or other drugs. Mental health problems, peer drug use, exposure to violence, and neighborhood characteristics did not differ between the groups. Regression analyses showed that the availability of drugs in the home had the greatest predictive value for hair-positive group membership while higher IQ, more nurturing home environments, and positive attachment to caregivers or peers exerted some protective effect.

Conclusion

The results do not support a direct relationship between PCE and early adolescent experimentation with cocaine. Proximal risk and protective factors—those associated with the home environment and preteens' caregivers—were more closely related to early cocaine use than more distal factors such as neighborhood characteristics. Consistent with theories of adolescent problem behavior, the data demonstrate the complexity of predicting pre-adolescent drug use and identify a number of individual and contextual factors that could serve as important foci for intervention.     

Initiation to drug injection among street youth: a gender-based analysis

Objective(s)

To estimate the incidence rate of initiation into drug injection and to identify predictors of initiation into drug injection separately among street girls and boys.

Design

Data from two consecutive prospective street youth cohort studies (1995-2001 and 2001-2005) were used to conduct these analyses, stratified by gender.

Methods

Data were collected using semi-annual interviewer-administered questionnaires. Variables from the following domains were considered in Cox regression models: socio-demographic characteristics, early and current substance abuse, marginalization, childhood traumatic sexual events and injection exposure.

Results

Of the 946 youth who had never injected drugs at study entry, 86.4% completed at least two questionnaires representing 243 girls and 574 boys. Incidence rates of injection of 7.0 and 5.9 per 100 person-years were observed among these girls and boys respectively. Among girls, cocaine or crack use (adjusted hazard ratio (AHR) = 1.97), heroin use (AHR = 2.86), homelessness (AHR = 2.49) and hanging out regularly with people who inject (AHR = 4.46) all independently increased risk of first injection. Among boys, age decreased risk of initiating injection (AHR = 0.90/year), while cocaine or crack use (AHR = 2.14), heroin use (AHR = 3.56), homelessness before age 16 (AHR = 1.68), incest or rape before age 14 (AHR = 1.98) and hanging out regularly with people who inject (AHR = 1.66) all independently increased this risk.

Conclusions

Our findings suggest similar rates of initiation among girls and boys; however, factors associated with initiation vary by gender. This might lead to the design of more effective programs to prevent initiation into drug injection.     

A randomized controlled trial of Structural Ecosystems Therapy for HIV medication adherence and substance abuse relapse prevention

Background

Substance abuse in women with HIV/AIDS overshadows other priorities, including health care. Substance abuse may cause women to avoid health care systems and not adhere to their medication regimen.

Methods

A randomized controlled trial tested the efficacy of Structural Ecosystems Therapy (SET) relative to a psychoeducational Health Group (HG) in 126 HIV+ women in recovery. SET, a 4-month intervention, focused on building family support for relapse prevention and HIV medication adherence. Over 12-month follow-up, women were assessed for drug use and medication adherence every 2 months; CD4 T-cell count and HIV viral load were assessed every 4 months.

Results

Levels of drug use did not differ by condition. There was a significant difference in curvature of the rates of change in drug use with SET increasing and then decreasing and HG decreasing and then increasing. Women in SET were more likely to increase substance abuse services in response to relapse and separate from drug using household members than were women in HG. These two changes explained the decline in drug use observed within SET between 6 and 12 months. SET showed declines in medication adherence but increases in CD4 T-cell count relative to HG. The increase in CD4 T-cell count in SET was related to increasing proportions of women in SET taking antiretroviral medications.

Conclusion

The results of the trial were mixed. Women in SET did not show better drug use or medication adherence outcomes, but did show improvement in CD4 T-cell count and theoretical mechanisms of action on drug relapse.     

Estimated effect of prenatal cocaine exposure on examiner-rated behavior at age 7 years

Prenatal cocaine exposure has been linked to increased child behavior difficulties in some studies but not others.

Objective

The primary aim was to estimate the relationship between in utero cocaine exposure and child behavioral functioning at age 7 years with ratings made by blinded examiners during a structured testing session. A second aim was to examine whether caregiver drug use and psychological problems might mediate suspected relationships between prenatal cocaine exposure and aspects of examiner-rated behavior.

Methods

407 children (212 cocaine-exposed, 195 non-exposed) participating in the longitudinal Miami Prenatal Cocaine Study (MPCS) were rated with regard to their behavior during a neuropsychological assessment conducted at age 7 years. Raters were trained research psychometricians blinded to drug exposure status. Individual behavioral items were summarized and the cocaine-behavior relationship was estimated within the context of latent variable modeling, using Mplus software.

Results

Two latent variables, Behavioral Regulation and Sociability, were derived via exploratory latent structure analysis with promax rotation. Prenatal cocaine exposure, statistically controlling for child sex, test age, and prenatal exposure to alcohol, tobacco, and marijuana, was associated with Behavioral Regulation (estimated slope ß = − 0.25; 95% CI = − 0.48, − 0.02; p = 0.04) but not Sociability (estimated slope ß = − 0.03; 95% CI = − 0.26, 0.20; p = 0.79). Neither postnatal drug use by caregivers nor the severity of their psychological problems at age 5 follow-up predicted levels of child Behavioral Regulation or Sociability at age 7 years (p > 0.10).

Conclusions

Examiner ratings of child behavior at age 7 revealed less optimal behavioral regulation for prenatally cocaine-exposed compared to non-exposed children, in contrast with what had been previously found from parent-report data. This evidence highlights the potential value of trained observers in assessing behavioral outcomes of children exposed in utero to drugs and other toxicants.     

Deficits in default mode network activity preceding error in cocaine dependent individuals

Background

Cocaine dependence is associated with cognitive deficits and altered task-related cerebral activation in cognitive performance (see Li and Sinha, 2008, for a review). Relatively little is known whether these individuals are also impaired in regional brain activation of the default mode network (DMN). We demonstrated previously that greater activation of the default brain regions precedes errors in a stop signal task performed by healthy controls (SST, Li et al., 2007). We seek to determine whether individuals with cocaine dependence are impaired in DMN activity, specifically activity preceding error, as compared to the healthy people. We also examine the relation to years of cocaine use.

Methods

Individuals with cocaine dependence (CD, n = 23) and demographics-matched healthy controls (HC, n = 27) performed a SST that employed a tracking procedure to adjust the difficulty of stop trials and elicit errors approximately half of the time. Blood oxygenation level dependent (BOLD) signals of go trials preceding stop error as compared to those preceding stop success trials were extracted with generalized linear models using statistical parametric mapping.

Results

HC showed activation of bilateral precuneus and posterior cingulate cortices and ventromedial prefrontal cortex (vmPFC) preceding errors during the SST. In contrast, despite indistinguishable stop signal performance, CD did not show these error predicting activations. Furthermore, the effect size of error-preceding vmPFC activation was inversely correlated with years of cocaine use.

Conclusions

These findings indicate DMN deficits and could potentially add to our understanding of the effects of chronic cocaine use on cerebral functions in cocaine dependence. Work to further clarify potential changes in functional connectivity and gray matter volume is warranted to understand the relevance of DMN to the pathology of cocaine misuse.     

Gender differences in physical and mental health outcomes among an aging cohort of individuals with a history of heroin dependence

Background

This paper examines the health status and functioning of an aging cohort of individuals with a history of heroin dependence with a focus on gender differences.

Method

Study subjects were originally sampled from methadone maintenance clinics in California in the 1970s and completed follow-up interviews in 2005-09. Out of the original study sample (N = 914), 343 participants (44.3% female) were interviewed (70.6% of those not deceased). Bivariate analyses examined gender differences in participants' overall health status and physical and mental health problems. Scores on SF-36 scales were compared with general population norms by gender and age, as well as between participants in the study sample who did and did not report past-year drug use.

Results

Average age of the study sample was 58.3 (SD = 4.9) years for males and 55.0 (SD = 4.1) years for females. There were no significant gender differences in past-year drug use (38% of sample) or injection drug use (19%). Women reported significantly more chronic health problems and psychological distress compared with men, and overall poorer health and functioning compared with general population norms. Men under 65 had poorer physical health and social functioning compared with population norms. Men in the study sample reporting past-year substance use had poorer physical functioning, but less bodily pain, than non-users, whereas women with past-year substance use had poorer mental health than other women.

Conclusion

Individuals with a history of heroin dependence have poorer health and functioning than their counterparts in the general population. At a younger age, women reported poorer overall health status and more chronic health and mental health problems than men. Study findings may inform interventions for this population, particularly related to gender-specific treatment needs.