Caregiver and self-report of mental health symptoms in 9-year old children with prenatal cocaine exposure

Objective

To assess the effect of prenatal cocaine exposure on mental health symptoms in 9-year old children controlling for potential confounders.

Methods

332 children (170 prenatally cocaine-exposed (PCE), 162 non cocaine-exposed (NCE) were assessed using self (Dominic Interactive; DI) and caregiver report (Child Behavior Checklist; CBCL).

Results

Higher levels of PCE were associated with caregiver report of clinically elevated aggressive and delinquent behavior. With each increased unit of PCE, children were 1.3 times more likely to be rated as aggressive (OR = 1.30, 95% CI: 1.02-1.67, p < 0.04). For each increased unit of PCE, girls were 2 times more likely to be rated as having delinquent behavior (OR = 2.08, 95% CI: 1.46-2.96, p < 0.0001). PCE status was also associated with increased odds of delinquent behavior (OR = 2.41; 95% CI: 1.16-4.97, p = 0.02), primarily due to the increased risk among girls with PCE. While girls with PCE status were 7 times more likely than NCE girls to have delinquent behaviors (OR = 7.42; 95% CI: 2.03-27.11, p < 0.002) boys with PCE did not demonstrate increased risk (OR = 0.98; 95% CI: 0.36-2.65, p > 0.97). Foster or adoptive parents were more likely to rate their PCE children as having more thought problems, inattention, delinquent behavior, aggression, externalizing and overall problems (p < 0.05) than biologic mothers or relative caregivers. Higher 2nd trimester tobacco exposure was associated with increased odds of caregiver reported anxiety (OR = 1.73; 95% CI 1.06-2.81, p < 0.03) and marijuana exposure increased the odds of thought problems (OR = 1.68; 95% CI 1.01-2.79, p < 0.05). Children with PCE self-reported fewer symptoms of oppositional defiant disorder (ODD) compared to NCE children (OR = 0.44, 95% CI: 0.21-0.92, p < 0.03). Greater tobacco exposure was associated with increased odds of child reported ODD (OR = 1.24; 95% CI 1.03-1.78, p < 0.03).

Conclusion

Higher PCE was associated with disruptive behaviors including aggression and delinquent behavior among girls by caregiver report, but not child report. These findings highlight the need for early behavioral assessment using multiple informants in multi-risk children.     

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.     

Prenatal cocaine exposure and small-for-gestational-age status: effects on growth at 6 years of age

Objective

To evaluate the impact of prenatal cocaine exposure and small-for-gestational-age (SGA) status on childhood growth.

Study design

Cocaine exposure was defined by history or meconium metabolites. Hierarchical linear modeling was used to examine cocaine exposure and SGA status on growth, while controlling for exposure to other drugs and alcohol use.

Results

At birth cocaine-exposed infants (n = 364) had significantly lower growth parameters compared to non-exposed children (n = 771). At 6 years, weight was similar between exposed and unexposed children. SGA infants continued to be growth impaired. There was a significant interaction between prenatal cocaine exposure and SGA status at 6 years. The negative effects of cocaine on weight and height were greater among non-SGA than SGA children (432 vs. 280 gm, and 0.7 and 0.5 cm, respectively) while negative effects of SGA status on weight and height were larger in non-cocaine exposed compared to the exposed children (2.3 kg vs.1.6 kg and 2.2 and 1.0 cm).

Conclusions

Children exposed to prenatal cocaine were similar in weight to non-exposed children at 6 years of age. Cocaine had an unexplained greater detrimental effect on non-SGA than SGA children. SGA status at birth has an independent detrimental effect on childhood growth.     

Executive dysfunction in chronic cocaine users: an exploratory study

Introduction

Chronic cocaine use is associated with some executive deficits. We assessed executive functions using ecologically valid tests in chronic cocaine users.

Objectives

To investigate the relationship between executive deficits and three measures of severity of cocaine use: years of use, quantity used, and frequency of use.

Methods

Twenty-four cocaine users were compared with twenty-seven community controls. We used Student's t-test and Chi-squared to compare means and categorical variables, respectively. Linear regression analyses for the adjusted comparative analysis between cases and controls, and severity of cocaine use among cocaine users were performed.

Results

Chronic cocaine users performed worse on measures of attention and working memory (Forward and Backward Digit Span, p < .001), set-shifting abilities (difference score between the Trail Making B and A, TMB-A, p = .006), cognitive test of mental flexibility and response inhibition (Rule Shift Cards) (p < .001), and prefrontal functioning (Wisconsin Card Sorting Test, WCST, p = .023) than controls. Years of cocaine use were associated with deficits in the Backward Digit Span (p = .041; CI 95%: −.760 to −.002), the TMB-A (p = .026; CI 95%: .687 to 9.761), the Zoo Map (p = .034; CI 95%: −.480 to −.021), and the Rule Shift Cards (p = .006; CI 95%: −.836 to −.164), among others. Quantity of cocaine use was associated with executive deficits measured by the Forward Digit Span (p = .007; CI 95%: −.727 to −.133), the TMB-A (p = .021; CI 95%: 5.304-57.945), and the number of perseverative errors in the WSCT (p = .002; CI 95%: −10.654 to −2.800). Frequency of cocaine was associated with deficits in the Backward Digit Span (p = .042; CI 95%: −1.548 to −.030).

Conclusions

Chronic use of cocaine is associated with executive deficits, which may influence patients’ functionality, prognosis, and therapeutic failure.     

The effects of prenatal cocaine on language development at 10 years of age

Objective

To examine the long term effects of prenatal cocaine exposure (PCE) on the language development of 10-year-old children utilizing a prospective design, controlling for confounding drug and environmental factors.

Participants

Children exposed to cocaine in utero (PCE; n = 175) and non-exposed children (NCE; n = 175) were followed prospectively to 10 years of age and were compared on language subscales of the Test of Language Development-Intermediate 3rd Edition (TOLD-I:3) and phonological processing as measured by the Comprehensive Test of Phonological Processing (CTOPP).

Methods

Multivariate analysis of covariance (MANCOVA), linear regression, and logistic regressions were used to evaluate the relationship of prenatal cocaine exposure to language development, while controlling for confounders.

Results

After controlling for confounding variables, prenatal cocaine effects were observed for specific aspects of language including syntax (Sentence Combining subtest of the TOLD-I:3, p = 0.001), semantics (Malopropism subtest of the TOLD-I:3, p = 0.05) and phonological processing (Phonological Awareness subscale, p = 0.01). The caregiver factors of vocabulary, HOME, and psychological symptoms also had consistent effects on language subtests and phonological processing scores. Children with PCE who experienced foster or adoptive care had enhanced language development compared to those living with birth mothers or in relative care. Cocaine exposed girls had lower scores on the phonological awareness subscale of the CTOPP than non-exposed girls.

Conclusions

PCE has subtle effects on specific aspects of language development and phonological processing at age 10, even after controlling for confounding variables. Environmental factors (i.e., postnatal lead exposure, home environment, and caregiver vocabulary and psychological symptoms) also impact language skills at 10 years. Adoptive or foster care appears to enrich PCE children's linguistic environment and protects children against language delay in the PCE sample.     

Preadolescent behavior problems after prenatal cocaine exposure: Relationship between teacher and caretaker ratings (Maternal Lifestyle Study)

Background

We previously reported an association between prenatal cocaine exposure (PCE) and childhood behavior problems as observed by the parent or caretaker. However, these behavior problems may not manifest in a structured environment, such as a school setting.

Objective

We determined whether there is an association between PCE and school behavior problems and whether ratings of behavior problems from the teacher differ from those noted by the parent or caretaker.

Methods

The Maternal Lifestyle Study, a multicenter study, enrolled 1388 children with and without PCE at one month of age for longitudinal assessment. Teachers masked to prenatal drug exposure status completed the Teacher Report Form (TRF/6-18) when children were 7, 9, and 11 years old. We also administered the Child Behavior Checklist-parent report (CBCL) to the parent/caretaker at same ages and then at 13 years. We performed latent growth curve modeling to determine whether high PCE will predict externalizing, internalizing, total behavior, and attention problems at 7 years of age and whether changes in problems' scores over time differ between those exposed and non-exposed from both teacher and parent report. Besides levels of PCE as predictors, we controlled for the following covariates, namely: site, child characteristics (gender and other prenatal drug exposures), family level influences (maternal age, depression and psychological symptomatology, continuing drug use, exposure to domestic violence, home environment, and socioeconomic status), and community level factors (neighborhood and community violence).

Results

The mean behavior problem T scores from the teacher report were significantly higher than ratings by the parent or caretaker. Latent growth curve modeling revealed a significant relationship between intercepts of problem T scores from teacher and parent ratings; i.e., children that were rated poorly by teachers were also rated poorly by their parent/caretaker or vice versa. After controlling for covariates, we found high PCE to be a significant predictor of higher externalizing behavior problem T scores from both parent and teacher report at 7 years (p = 0.034 and p = 0.021, respectively) in comparison to non-PCE children. These differences in scores from either teacher or caregiver were stable through subsequent years or did not change significantly over time. Boys had higher T scores than girls on internalizing and total problems by caretaker report; they also had significantly higher T scores for internalizing, total, and attention problems by teacher ratings; the difference was marginally significant for externalizing behavior (p = 0.070). Caretaker postnatal use of tobacco, depression, and community violence were significant predictors of all behavior problems rated by parent/caretaker, while lower scores on the home environment predicted all behavior outcomes by the teacher report.

Conclusions

Children with high PCE are likely to manifest externalizing behavior problems; their behavior problem scores at 7 years from either report of teacher or parent remained higher than scores of non-exposed children on subsequent years. Screening and identification of behavior problems at earlier ages could make possible initiation of intervention, while considering the likely effects of other confounders.     

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.     

Exposure to alcohol during adolescence alters the aversive and locomotor-activating effects of cocaine in adult rats

Objectives

The present study assessed the effect of adolescent alcohol exposure on the later aversive and locomotor-activating effects of cocaine.

Methods

Male rats were exposed to alcohol or vehicle for 10 days [postnatal day (PND) 30-39; 2 g/kg IP]. Taste aversion conditioning began on PND 65. During aversion conditioning, subjects were presented with saccharin followed by cocaine (32 mg/kg; 15, 180 or 300 min post saccharin) or saline. Following each injection, animals were placed in locomotor chambers for 1 h. To determine if any effects seen were specific to the adolescent developmental period, the procedure was replicated in adult animals.

Results

Animals exposed to vehicle during adolescence showed significant aversions at all time delays. Animals exposed to ethanol during adolescence showed a decrease in consumption only at the 15 and 180 min delays. Groups exposed to alcohol during adolescence showed a decrease in gross, and an increase in fine, motor activity in response to cocaine. Animals exposed to alcohol during adulthood also showed attenuated taste aversions.

Conclusions

Exposure to ethanol during adolescence attenuated the aversive effects of cocaine and altered its locomotor-activating effects. Although this effect is not specific to adolescence, this is the time when alcohol use is typically initiated so that such exposure may enhance later abuse liability of cocaine.     

Prenatal and postnatal cocaine exposure predict teen cocaine use

Preclinical studies have identified alterations in cocaine and alcohol self-administration and behavioral responses to pharmacological challenges in adolescent offspring following prenatal exposure. To date, no published human studies have evaluated the relation between prenatal cocaine exposure and postnatal adolescent cocaine use. Human studies of prenatal cocaine-exposed children have also noted an increase in behaviors previously associated with substance use/abuse in teens and young adults, specifically childhood and teen externalizing behaviors, impulsivity, and attention problems. Despite these findings, human research has not addressed prior prenatal exposure as a potential predictor of teen drug use behavior. The purpose of this study was to evaluate the relations between prenatal cocaine exposure and teen cocaine use in a prospective longitudinal cohort (n = 316) that permitted extensive control for child, parent and community risk factors. Logistic regression analyses and Structural Equation Modeling revealed that both prenatal exposure and postnatal parent/caregiver cocaine use were uniquely related to teen use of cocaine at age 14 years. Teen cocaine use was also directly predicted by teen community violence exposure and caregiver negativity, and was indirectly related to teen community drug exposure. These data provide further evidence of the importance of prenatal exposure, family and community factors in the intergenerational transmission of teen/young adult substance abuse/use.     

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.     

A new look at quantifying tobacco exposure during pregnancy using fuzzy clustering

Background

Prenatal tobacco exposure is a risk factor for the development of externalizing behaviors and is associated with several adverse health outcomes. Because pregnancy smoking is a complex behavior with both daily fluctuations and changes over the course of pregnancy, quantifying tobacco exposure is a significant challenge. To better measure the degree of tobacco exposure, costly biological specimens and repeated self-report measures of smoking typically are collected throughout pregnancy. With such designs, there are multiple, and substantially correlated, indices that can be integrated via new statistical methods to identify patterns of prenatal exposure.

Method

A multiple-imputation-based fuzzy clustering technique was designed to characterize topography of prenatal exposure. This method leveraged all repeatedly measured maternal smoking variables in our sample data, including (a) cigarette brand; (b) Fagerstrom nicotine dependence item scores; (c) self-reported smoking; and (d) cotinine level in maternal urine and infant meconium samples. Identified exposure groups then were confirmed using a suite of clustering validation indices based on multiple imputed datasets. The classifications were validated against irritable reactivity in the first month of life and birth weight of 361 neonates (Male_{_n} = 185; Female_{_n} = 176; Gestational Age__Mean = 39 weeks).

Results

This proposed approach identified three exposure groups, non-exposed, lighter-tobacco-exposed, and heavier-tobacco-exposed based on high-dimensional attributes. Unlike cut-off score derived groups, these groupings reflect complex smoking behavior and individual variation of nicotine metabolism across pregnancy. The identified groups predicted differences in birth weight and in the pattern of change in neonatal irritable reactivity, as well as resulted in increased predictive power. Multiple-imputation-based fuzzy clustering appears to be a useful method to categorize patterns of exposure and their impact on outcomes.     

Prenatal exposure to multiple toxic heavy metals and neonatal neurobehavioral development in Shanghai, China

Background

Epidemiological studies examining the effects of prenatal toxic heavy metals exposure on neonatal development at the population-based level are limited.

Objective

To explore prenatal exposure levels to toxic heavy metals and examine whether exposure is associated with neonatal development.

Methods

A stratified multi-stage cluster sampling methodology was used to investigate 1652 mother-infant pairs from 2008 through 2009 in Shanghai. Cord blood concentrations of Pb, Hg, Cd, As, Tl and NBNA (Neonatal Behavioral Neurological Assessments) were tested. We defined three different exposure levels (low, medium and high) according to the considered safe values.

Results

The median blood Pb, Hg, Cd, As and Tl concentrations were 41 μg/L, 1.88 μg/L, 0.03 μg/L, 0.86 μg/L and 0.02 μg/L, respectively, which all were in the level considered safe. Increasing exposure to Cd, Hg, As and Tl during pregnancy was associated with decreasing NBNA scores. High level-exposure (exceeding the level considered safe) of Hg, Cd and Tl had lower NBNA scores compared to medium and low levels (both in the level considered safe), which implied that the level considered safe of these heavy metals was safe for the newborns' development. The mean decreasing scores of NBNA was 0.61, 1.50 and 0.84 (total score = 40) with high-level exposure of Hg, Cd and Tl, respectively. The medium-level exposure (in the level considered safe) to As had lower NBNA scores compared to low-level exposure, which implied that level of considered safe for As was not safe to the newborns' development. However, prenatal Pb high-exposure did not affect NBNA scores either by single or multiple factor analysis. In addition, important contribution factors for heavy metals pollutants were diet, lifestyle and housing renovation.

Conclusions

Prenatal heavy metals except Pb exposures were associated with NBNA. The adverse effect of medium-level As warrants the need to further investigate the safe range of As.     

Motor and cognitive outcomes through three years of age in children exposed to prenatal methamphetamine

Background

Methamphetamine (MA) use among pregnant women is an increasing problem in the United States. The impact of prenatal MA exposure on development in childhood is unknown.

Objective

To examine the effects of prenatal MA exposure on motor and cognitive development in children at 1, 2, and 3 years of age.

Design/methods

IDEAL enrolled 412 mother-infant pairs at four sites (Tulsa OK, Des Moines IA, Los Angeles CA, and Honolulu HI). MA subjects (n = 204) were identified by self report or GC/MS confirmation of amphetamine and metabolites in infant meconium. Comparison subjects (n = 208) were matched (race, birth weight, maternal education, and type of insurance), denied amphetamine use, and had a negative meconium screen. Both groups included prenatal alcohol, tobacco and marijuana use, but excluded use of opiates, lysergic acid diethylamide, phencyclidine or cocaine only. The Peabody Developmental Motor Scales (PDMS-2) were administered to the infants at the 1 and 3 year visits. This analysis includes a subsample (n = 350) of the IDEAL study with completed 1 and/or 3 year visits (n = 330 and 281, respectively). At each annual visit we also conducted the Bayley Scales of Infant Development (BSID-II) as a general evaluation of mental and motor development. The BSID-II analysis includes a subsample (n = 356) of the IDEAL study with completed 1, 2, and/or 3 year visits (n = 331, 288, and 278 respectively). GLM analysis conducted on the PDMS-2 and BSID-II examined the effects of MA exposure and heavy MA exposure (≥ 3 days of use/week), with and without covariates. Longitudinal analyses were used to examine the effects of MA exposure on changes in motor and cognitive performance over time.

Results

Heavy MA exposure was associated with significantly lower grasping scores than some and no use at 1 year (P = 0.018). In longitudinal analysis, lower grasping scores associated with any MA exposure and heavy exposure persisted to 3 years. There were no effects of MA exposure, including heavy exposure, on the Bayley Mental Development Index (MDI) or Psychomotor Development Index (PDI) at any or across age.

Conclusions

There were no differences in cognition as assessed by the BSID-II between the groups. There was a subtle MA exposure effect on fine motor performance at 1 year with the poorest performance observed in the most heavily exposed children. By 3 years, no differences in fine motor performance were observed. These findings suggest MA exposure has modest motor effects at 1 year that are mostly resolved by 3 years.     

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.     

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.     

Beliefs and attitudes regarding drug treatment: Application of the Theory of Planned Behavior in African-American cocaine users

Background

The Theory of Planned Behavior (TPB) can provide insights into perceived need for cocaine treatment among African American cocaine users.

Methods

A cross-sectional community sample of 400 (50% rural) not-in-treatment African-American cocaine users was identified through respondent-driven sampling in one urban and two rural counties in Arkansas. Measures included self-reports of attitudes and beliefs about cocaine treatment, perceived need and perceived effectiveness of treatment, and positive and negative cocaine expectancies. Normative beliefs were measured by perceived stigma and consequences of stigma regarding drug use and drug treatment. Perceived control was measured by readiness for treatment, prior drug treatment, and perceived ability to cut down on cocaine use without treatment.

Findings

Multiple regression analysis found that older age (standardized regression coefficient β = 0.15, P < 0.001), rural residence (β = − 0.09, P = 0.025), effectiveness of treatment (β = 0.39, P < 0.001), negative cocaine expectancies (β = 0.138, P = 0.003), experiences of rejection (β = 0.18, P < 0.001), need for secrecy (β = 0.12, P = 0.002), and readiness for treatment (β = 0.15, P < 0.001) were independently associated with perceived need for cocaine treatment.

Conclusions

TPB is a relevant model for understanding perceived need for treatment among African-American cocaine users. Research has shown perceived need to be a major correlate of treatment participation. Study results should be applicable for designing interventions to encourage treatment participation.     

A single-day paradigm of self-regulated human cocaine administration

Prior work by our group has shown the feasibility, safety, and validity of a multi-day, multi-dose paradigm of self-regulated cocaine administration in humans. The current work sought to consolidate these methods in a single-day design focused on reducing logistical complexity, decreasing research burden to human subjects, and increasing suitability for medication development designs.

Methods

Eleven experienced cocaine users participated in a 6-hour, single-day design, consisting of one safety/eligibility and three experimental cocaine periods (during which subjects were allowed to self-administer 8, 16, and 32 mg/70 kg cocaine doses under a fixed-ratio 1:5 minute timeout schedule). Changes in cocaine-induced cardiovascular response, self-administration behavior, and subjective effects were assessed.

Results

Procedures were well tolerated by participants, and no significant adverse events were noted. Significant (p < 0.05), changes in measures of cocaine self-administration (e.g., responses, infusions, interinfusion intervals, consumption, and plasma levels), cardiovascular response (HR), and subjective effects (“high”) were observed. In contrast, cocaine-induced increases in other vital signs (e.g., SBP, DBP) and subjective effect measures (e.g., paranoia) did not differ between doses.

Conclusions

These data support the safety, tolerability and validity of our single-day design. Depending on the application, such methods may afford advantages for assessing the self-regulation of cocaine administration behavior in humans (e.g., including medication development designs).     

Chronic hepatitis C virus infection and increases in viral load in a prospective cohort of young, HIV-uninfected injection drug users

Background

Chronic hepatitis C (HCV) infection, defined as persistent RNA (viral load) for at least 6 months, accounts for up to 50% of all cirrhosis, end-stage liver disease and liver cancer cases. Moreover, elevated HCV viral load is consistently associated with high infectivity and poor therapy response. This study aims to identify modifiable behavioral correlates both chronic HCV infection and increases in viral load over time among injection drug users (IDUs).

Methods

Cross-sectional and longitudinal analyses were performed using self-interview and serological data from a prospective cohort study (2002-2006) among young (age 18-35), HIV-negative, HCV therapy-naïve IDUs (n = 113) from metropolitan Chicago, Illinois, USA.

Results

After adjustment for age, gender and race/ethnicity, using drugs measured or mixed in someone else's syringe (odds ratio = 2.7, 95% confidence interval: 1.1, 6.7) was associated with chronic (n = 75, 66%) versus resolved (n = 38, 34%) HCV infection status. Among chronically-infected IDUs, injecting with a new, sterile syringe infrequently (<1/2 half the time when injecting) compared to frequently (1/2 the time or more when injecting) was associated with increases in viral load over time after adjusting for age, gender, race/ethnicity and time effects.

Conclusions

Reductions in risky injection-related practices among young IDUs may ameliorate both the burden of chronic HCV infection-related liver disease and elevated viral load-related poor treatment response.     

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

Background

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

Methods

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

Results

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

Conclusions

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

Childhood predictors of first chance to use and use of cannabis by young adulthood

Aims

To prospectively examine the linkage between childhood antecedents and progression to early cannabis involvement as manifest in first chance to try it and then first onset of cannabis use.

Methods

Two consecutive cohorts of children entering first grade of a public school system of a large mid-Atlantic city in the mid 1980s (n = 2311) were assessed (mean age 6.5 years) and then followed into young adulthood (15 years later, mean age 21) when first chance to try and first use were assessed for 75% (n = 1698) of the original sample. Assessments obtained at school included standardized readiness scores (reading; math) and teacher ratings of behavioral problems. Regression and time to event models included covariates for sex, race, and family disadvantage.

Results

Early classroom misconduct, better reading readiness, and better math readiness predicted either occurrence or timing of first chance to try cannabis, first use, or both. Higher levels of childhood concentration problems and lower social connectedness were not predictive.

Conclusions

Childhood school readiness and behavioral problems may influence the risk for cannabis smoking indirectly via an increased likelihood of first chance to use. Prevention efforts that seek to shield youths from having a chance to try cannabis might benefit from attention to early predictive behavioral and school readiness characteristics. When a youth's chance to try cannabis is discovered, there are new windows of opportunity for prevention and intervention.