Prevalence and predictors of injection drug use and risky sexual behaviors among adolescents in substance treatment.

BACKGROUND AND OBJECTIVES: The longitudinal risk for human immunodeficiency virus (HIV) infection following adolescent substance treatment is not known. Therefore, it is not known if adolescent substance treatment should include HIV prevention interventions. To address this important research gap, this study evaluates the longitudinal prevalence and predictors of injection drug use (IDU) and sex risk behaviors among adolescents in substance treatment. METHODS: Participants were 260 adolescents (13-18 years) in substance treatment and 201 community control adolescents (11-19 years). Participants were assessed at baseline and follow-up (mean time between assessments = 6.9 years for the clinical sample and 5.6 years for the community control sample). Outcomes included self-report lifetime history of IDU, number of lifetime sex partners and frequency of unprotected sexual intercourse. RESULTS: At baseline, 7.5% of the clinical sample, compared to 1.0% of the community control sample had a lifetime history of IDU (χ12=10.53, p = .001). At follow-up, 17.4% of the clinical sample compared to 0% of the community control sample had a lifetime history of IDU (χ12=26.61, p = .0005). The number of baseline substance use disorders and onset age of marijuana use significantly predicted the presence of lifetime IDU at follow-up, after adjusting for baseline age, race, and sex. The clinical sample reported more lifetime sex partners and more frequent unprotected sex than the community control sample at baseline and follow-up. CONCLUSIONS: Many adolescents in substance treatment develop IDU and report persistent risky sex. Effective risk reduction interventions for adolescents in substance treatment are needed that address both IDU and risky sex.

Item response theory analysis of DSM-IV cannabis abuse and dependence criteria in adolescents.

OBJECTIVE: To examine three aspects of adolescent cannabis problems: do DSM-IV cannabis abuse and dependence criteria represent two different levels of severity of substance involvement, to what degree do each of the 11 abuse and dependence criteria assess adolescent cannabis problems, and do the DSM-IV items function similarly across different adolescent populations? METHOD: We examined 5,587 adolescents ages 11 to 19, including 615 youths in treatment for substance use disorders, 179 adjudicated youths, and 4,793 youths from the community. All of the subjects were assessed with a structured diagnostic interview. Item response theory was used to analyze symptom endorsement patterns. RESULTS: Abuse and dependence criteria were not found to represent different levels of severity of problem cannabis use in any of the samples. Among the 11 abuse and dependence criteria, problems cutting down and legal problems were the least informative for distinguishing problem users. Two dependence criteria and three of the four abuse criteria indicated different severities of cannabis problems across samples. CONCLUSIONS: We found little evidence to support the idea that abuse and dependence are separate constructs for adolescent cannabis problems. Furthermore, certain abuse criteria may indicate severe substance problems, whereas specific dependence items may indicate less severe problems. The abuse items in particular need further study. These results have implications for the refinement of the current substance use disorder criteria for DSM-V.

Test of alternative hypotheses explaining the comorbidity between attention-deficit/hyperactivity disorder and conduct disorder.

There is significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD). The conclusions of studies that examined the causes of comorbidity between ADHD and CD conflict, with some researchers finding support for the three independent disorders model and others finding support for the correlated risk factors model. We tested these models and eleven alternative hypotheses using the same analytical approach. The participants were 110 monozygotic twin pairs and 181 dizygotic twin pairs recruited from the Colorado Learning Disabilities Research Center Twin Study. The three independent disorders model did not fit the data, whereas the correlated risk factors model fit the data well. Several other comorbidity models fit the data as well as or better than the correlated risk factors model. The results suggest that correlated risk factors are a better explanation for the comorbidity between ADHD and CD than a third, independent ADHD+CD subtype.

Intimate Partner Violence and Animal Abuse in an Immigrant-Rich Sample of Mother-Child Dyads Recruited From Domestic Violence Programs.

We examined rates of animal abuse in pet-owning families experiencing intimate partner violence (IPV). We also examined whether higher levels of IPV (as measured by subscales from the Conflict Tactics Scales) predicted increased risk for partner-perpetrated animal abuse. Our sample included 291 mother-child dyads, where the mothers sought services from domestic violence agencies. Nearly half the sample is comprised of Mexican immigrants. Mothers reported that 11.7% of partners threatened to harm a pet and 26.1% actually harmed a pet, the latter of which represents a lower rate than in similar studies. When examining animal abuse by "Hispanic status," follow-up analyses revealed significant omnibus differences between groups, in that non-Hispanic U.S.-born partners (mostly White) displayed higher rates of harming pets (41%) than either U.S.-born or Mexican-born Hispanic groups (27% and 12.5%, respectively). Differences in rates for only threatening (but not harming) pets were not significant, possibly due to a small number of partners ( n = 32) in this group. When examining whether partners' IPV predicted only threatening to harm pets, no IPV subscale variables (Physical Assault, Psychological Aggression, Injury, or Sexual Coercion) were significant after controlling for income, education, and Hispanic status. When examining actual harm to pets, more Psychological Aggression and less Physical Assault significantly predicted slightly higher risk of harm. However, Mexican-born partners had nearly 4 times lower risk of harming a pet. Overall, these results suggest that Hispanic men who are perpetrators of IPV are less likely to harm pets than non-Hispanic perpetrators of IPV, particularly if Mexican-born. Considering that the United States has a significant proportion of Mexican immigrants, it may be worthwhile to explore the topics of IPV and animal abuse within this group.

A genome-wide scan for loci influencing adolescent cannabis dependence symptoms: evidence for linkage on chromosomes 3 and 9.

OBJECTIVE: Cannabis is the most frequently abused illicit substance among adolescents and young adults. Genetic risk factors account for part of the variation in the development of cannabis dependence symptoms; however, no linkage studies have been performed for cannabis dependence symptoms. This study aimed to identify such loci. METHOD: Three hundred and twenty-four sibling pairs from 192 families were assessed for cannabis dependence symptoms. Probands (13-19 years of age) were recruited from consecutive admissions to substance abuse treatment facilities. The siblings of the probands ranged in age from 12 to 25 years. A community-based sample of 4843 adolescents and young adults was utilized to define an age- and sex-corrected index of cannabis dependence vulnerability. DSM-IV cannabis dependence symptoms were assessed in youth and their family members with the Composite International Diagnostic Instrument-Substance Abuse Module. Siblings and parents were genotyped for 374 microsatellite markers distributed across the 22 autosomes (average inter-marker distance=9.2cM). Cannabis dependence symptoms were analyzed using Merlin-regress, a regression-based method that is robust to sample selection. RESULTS: Evidence for suggestive linkage was found on chromosome 3q21 near marker D3S1267 (LOD=2.61), and on chromosome 9q34 near marker D9S1826 (LOD=2.57). CONCLUSIONS: This is the first reported linkage study of cannabis dependence symptoms. Other reports of linkage regions for illicit substance dependence have been reported near 3q21, suggesting that this region may contain a quantitative trait loci influencing cannabis dependence and other substance use disorders.

Modeling rater disagreement for ADHD: are parents or teachers biased?

The present study is the first to utilize twin modeling to examine whether parent-teacher disagreement for ADHD ratings is due to parent or teacher bias, or due to raters observing different but valid ADHD behaviors. A joint analysis was conducted with 106 twin pairs, including twins selected for ADHD and control twin pairs. Total ADHD scores were analyzed using multiple rater models that estimate genetic and environmental contributions common to both raters and unique to each rater. Results suggest that 1) disagreement in ADHD ratings is strongly due to parents and teachers observing different ADHD behaviors, some of which is valid and some of which is due to bias, and 2) parents may be more biased than teachers in their ADHD ratings.

The family transmission of adolescent alcohol abuse and dependence.

OBJECTIVE: This study examines the familial transmission of alcohol abuse and dependence to adolescents. METHOD: Male adolescents recruited from a treatment program for substance problems, matched controls, and all available biological parents and siblings were assessed with a structured psychiatric interview assessing Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, based diagnoses of alcohol abuse and alcohol dependence. A total of 2,612 individuals from 911 families were interviewed. Structural equation modeling estimated tetrachoric correlations among family members, the proportion of variance in abuse and dependence attributable to parent-offspring transmission, and the effects of assortative mating and horizontal transmission among siblings. RESULTS: Tetrachoric correlations among siblings and parent-offspring ranged from .19 to .34 for abuse and dependence. Mother-father correlations were .14 and .37 for abuse and dependence, respectively. Modeling of familial transmission showed that 33% of the variance in abuse and 56% of the variance in dependence was accounted for by factors transmitted from parents. The effects of assortative mating could not be dropped from the abuse model without significant loss of model fit but could be dropped from the dependence model. Horizontal transmission among siblings could be dropped from both models without significant loss of fit. CONCLUSIONS: These results suggest that aggregation of alcohol abuse and alcohol dependence in families of male probands is significantly influenced by parental transmission of risk but is not reliably influenced by horizontal sibling effects such as sibling interactions or cohort effects. Spousal resemblance was found to be an important source of familial aggregation for alcohol abuse but not alcohol dependence.

The relation between sluggish cognitive tempo and DSM-IV ADHD.

To test the relation between sluggish cognitive tempo (SCT) and DSM-IV ADHD symptoms, parent and teacher ratings of the 18 DSM-IV ADHD items and five potential SCT items were obtained in a community sample of 8-18 year-old twins that was overselected for ADHD and learning disabilities (n = 296). Confirmatory factor analyses revealed that a three-factor model provided the best fit to the data for both parent and teacher ratings. DSM-IV inattention and hyperactivity-impulsivity symptoms loaded on two factors consistent with the DSM-IV model, and five SCT symptoms loaded primarily on a third factor. The SCT and inattention factors were highly correlated, whereas SCT and hyperactivity-impulsivity were weakly related. Both raters indicated that children meeting symptom criteria for the combined and inattentive subtypes exhibited significantly more SCT symptoms than those meeting symptom criteria for hyperactive-impulsive type and the comparison group without ADHD. Children meeting symptom criteria for the inattentive type exhibited significantly more SCT symptoms than those meeting criteria for the combined type, based on teacher ratings. These results suggest that SCT is an internally consistent construct that is significantly associated with DSM-IV inattention.

The association between cannabinoid receptor 1 gene (CNR1) and cannabis dependence symptoms in adolescents and young adults.

OBJECTIVE: This study examined the genetic association between variation in the cannabinoid receptor 1 (CNR1) gene and cannabis dependence symptoms. METHOD: Adolescent and young adult subjects were recruited from three settings: a treatment program for youth with substance use disorders, the criminal justice system, and the community. A case-control sample consisted of 224 cases who endorsed at least one dependence symptom and 108 controls who tried cannabis but endorsed no symptoms. A family-based sample of 219 families was also analyzed. RESULTS: Case-control analysis identified a nominal association between SNP rs1049353 and having one or more cannabis dependence symptoms (p=.029), but the association did not hold up in a combined sample. Family-based analysis found a trend for the same SNP (p=.07). We did not replicate a previous report that SNP rs806380 was associated with the development of cannabis dependence. CONCLUSION: These results provide inconclusive evidence of association between rs1049353/rs806380 and the development of cannabis dependence, and underscore the importance of replicating results of genetic association studies. Additional family-based studies are needed to clarify the role of the CNR1 gene, and its various SNPs, in the development of cannabis use disorders.