Ty A. Ridenour

Measurement of the Risk for Substance Use Disorders: Phenotypic and Genetic Analysis of an Index of Common Liability

The inability to quantify the risk for disorders, such as substance use disorders (SUD), hinders etiology research and development of targeted intervention. Based on the concept of common transmissible liability to SUD related to illicit drugs, a method enabling quantification of this latent trait has been developed, utilizing high-risk design and item response theory. This study examined properties of a SUD transmissible liability index (TLI) derived using this method. Sons of males with or without SUD were studied longitudinally from preadolescence to young adulthood. The properties of TLI, including its psychometric characteristics, longitudinal risk assessment and ethnic variation, were examined. A pilot twin study was conducted to analyze the composition of TLI’s phenotypic variance. The data suggest that TLI has concurrent, incremental, predictive and discriminant validity, as well as ethnic differences. The data suggest a high heritability of the index in males. The results suggest applicability of the method for genetic and other etiology-related research, and for evaluation of individual risk.

Prediction of Cannabis Use Disorder between Boyhood and Young Adulthood: Clarifying the Phenotype and Environtype

Employing a prospective paradigm, this investigation derived the childhood phenotype and the environtype associated with risk for cannabis use disorder. Two hundred and sixteen boys were evaluated between age 10-12 on a comprehensive protocol using self, mother, and teacher reports and followed-up at ages 19 and 22 to determine the presence of cannabis use disorder. The Transmissible Liability Index (TLI) and Non-Transmissible Liability Index (NTLI) were derived using item response theory. Logistic regression was conducted to evaluate the accuracy of the indexes, singly and in combination, to predict cannabis use disorder. The TLI and NTLI together predicted with 70% and 75% accuracy cannabis use disorder manifest by age 19 and age 22. Sensitivity was 75% at both ages 19 and 22, whereas specificity was respectively 51% and 64%. The findings pertaining to sensitivity indicate that SUD risk for cannabis use disorder can be screened in childhood; however, the specificity scores demonstrate that a low score on the TLI does not inevitably portend a good prognosis up to 10 years later.

The Longitudinal Effect of Technical Assistance Dosage on the Functioning of Communities That Care Prevention Boards in Pennsylvania

This study examined the impact of on-site and off-site technical assistance (TA) dosage on the functioning of Communities That Care prevention boards in Pennsylvania. Data on board functioning were collected over three years from board member and TA providers. Results of path models indicated little overall impact of TA dosage on board functioning the subsequent year. However, on-site TA dosage did appear to influence board functioning for younger boards and for boards who were relatively better functioning. In addition, the stability of board functioning and off-site TA was moderate to strong, the stability of on-site TA dosage was low, and poor functioning sites did not receive more TA in the following year. Editors’ Strategic Implications: This paper is one of the first quantitative examinations of the impact of TA on community-based prevention or health promotion coalitions. The authors provide a number of implications for further study with respect to TA. Thus, it should be valuable to researchers and practitioners involved in the development and implementation of such community-based efforts.

Towards a comprehensive developmental model of cannabis use disorders

AIMS To develop a comprehensive risk-factor model of cannabis use disorders (CUD) based on Kendlers development model for major depression. DESIGN Risk factors were divided into five developmental tiers based on Kendlers model of depression (childhood, early adolescence, late adolescence, adulthood, past year). Hierarchical logistic regression models were used to examine the independent contribution of each risk factor. Separate models were built to predict the lifetime risk of cannabis use and the risk of CUD among those with a history of lifetime risk of cannabis use. SETTING Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) in the United States. PARTICIPANTS Participants consisted of wave 2 of the NESARC (n = 34 653). MEASUREMENTS Odds ratios (OR), Adjusted OR (AOR) and confidence intervals (95% CI) were used to determine the risk factors in each tier and with multiple models. FINDINGS After mutually adjusting for the effect of other risk factors, lifetime history of drug use disorder (AOR = 4.78, 95% CI = 1.53-14.91), past year alcohol use disorders (AOR = 6.55, 95% CI = 2.54-16.89) and independent (AOR = 1.57, 95% CI = 1.15-2.14) and dependent (AOR = 1.25, 95% CI = 1.01-1.55) stressful life events predicted lifetime cannabis use. Impulsivity (AOR = 2.18, 95% CI = 1.34-3.53), past year alcohol use disorders (AOR = 4.09, 95% CI = 2.29-7.31), greater number of Axis I disorders (AOR = 1.56, 95% CI = 1.01-2.40) and social deviance (AOR = 1.19, 95% CI = 1.08-1.32) independently increased the risk of the development of CUD, whereas religious service attendance (AOR = 0.50, 95% CI = 0.30-0.85) decreased this risk. In both models, the effect of earlier development tiers was mediated by more proximal ones. There were few gender differences in both models. CONCLUSIONS A modification of Kendlers risk factor model for major depression which stratifies risk factors into five groups (childhood, early adolescence, late adolescence, adulthood, past year) provides a useful foundation for a comprehensive developmental model of cannabis use and cannabis use disorders.

Neurobehavior disinhibition, parental substance use disorder, neighborhood quality and development of cannabis use disorder in boys.

This prospective investigation examined the contribution of neighborhood context and neurobehavior disinhibition to the association between substance use disorder (SUD) in parents and cannabis use disorder in their sons. It was hypothesized that both neighborhood context and sons neurobehavior disinhibition mediate this association. Two hundred and sixteen boys were tracked from ages 10-12 to age 22. The extent to which neighborhood context and neurobehavior disinhibition mediate the association between parental SUD and sons cannabis use disorder was evaluated using structural equation modeling. The best fitting model positioned neighborhood context and neurobehavior disinhibition as mediators of the association between parental SUD and cannabis use disorder in sons. Neurobehavior disinhibition also was a mediator of the association between neighborhood context and sons cannabis use. The implications of this pattern of association between parental SUD, neighborhood context and individual risk for SUD for improving prevention are discussed.

Deviant socialization mediates transmissible and contextual risk on cannabis use disorder development: a prospective study

AIMS This study examined the contribution of transmissible risk, in conjunction with family and peer contextual factors during childhood and adolescence, on the development of cannabis use disorder in adulthood. DESIGN The family high-risk design was used to recruit proband fathers with and without substance use disorder and track their sons longitudinally from late childhood to adulthood. SETTING The families were recruited under the aegis of the Center for Education and Drug Abuse Research in Pittsburgh, Pennsylvania. PARTICIPANTS The oldest son in the family was studied at ages 10-12, 16, 19 and 22 years. MEASUREMENTS The transmissible liability index (TLI), along with measures of quality of the parent-child relationship, cooperative behavior at home, social attitudes and peer milieu were administered to model the developmental pathway to cannabis use disorder. FINDINGS Affiliation with socially deviant peers and harboring non-normative attitudes (age 16) mediate the association between transmissible risk for substance use disorder (SUD) (age 10-12) and use of illegal drugs (age 19), leading to cannabis use disorder (age 22). CONCLUSIONS Deviant socialization resulting from transmissible risk and poor parent-child relationship is integral to development of cannabis use disorder in young adulthood.

Could a continuous measure of individual transmissible risk be useful in clinical assessment of substance use disorder? Findings from the National Epidemiological Survey on Alcohol and Related Conditions☆

OBJECTIVE Toward meeting the need for a measure of individual differences in substance use disorder (SUD) liability that is grounded in the multifactorial model of SUD transmission, this investigation tested to what degree transmissible SUD risk is better measured using the continuous Transmissible Liability Index (TLI) (young adult version) compared to alternative contemporary clinical methods. METHOD Data from 9535 18- to 30-year-olds in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions, a U.S. representative sample, were used to compute TLI scores and test hypotheses. Other variables were SUDs of each DSM-IV drug class, clinical predictors of SUD treatment outcomes, treatment seeking and usage, age of onset of SUDs and substance use (SU), and eligibility for SUD clinical trials. RESULTS TLI scores account for variation in SUD risk over and above parental lifetime SUD, conduct and antisocial personality disorder criteria and frequency of SU. SUD risk increases two- to four-fold per standard deviation increment in TLI scores. The TLI is associated with SUD treatment seeking and usage, younger age of onset of SU and SUD, and exclusion from traditional clinical trials of SUD treatment. CONCLUSIONS The TLI can identify persons with high versus low transmissible SUD risk, worse prognosis of SUD recovery and to whom extant SUD clinical trials results may not generalize. Recreating TLI scores in extant datasets facilitates etiology and applied research on the full range of transmissible SUD risk in development, treatment and recovery without obtaining new samples.

Toward Rigorous Idiographic Research in Prevention Science: Comparison Between Three Analytic Strategies for Testing Preventive Intervention in Very Small Samples

Psychosocial prevention research lacks evidence from intensive within-person lines of research to understand idiographic processes related to development and response to intervention. Such data could be used to fill gaps in the literature and expand the study design options for prevention researchers, including lower-cost yet rigorous studies (e.g., for program evaluations), pilot studies, designs to test programs for low prevalence outcomes, selective/indicated/adaptive intervention research, and understanding of differential response to programs. This study compared three competing analytic strategies designed for this type of research: autoregressive moving average, mixed model trajectory analysis, and P-technique. Illustrative time series data were from a pilot study of an intervention for nursing home residents with diabetes (N = 4) designed to improve control of blood glucose. A within-person, intermittent baseline design was used. Intervention effects were detected using each strategy for the aggregated sample and for individual patients. The P-technique model most closely replicated observed glucose levels. ARIMA and P-technique models were most similar in terms of estimated intervention effects and modeled glucose levels. However, ARIMA and P-technique also were more sensitive to missing data, outliers and number of observations. Statistical testing suggested that results generalize both to other persons as well as to idiographic, longitudinal processes. This study demonstrated the potential contributions of idiographic research in prevention science as well as the need for simulation studies to delineate the research circumstances when each analytic approach is optimal for deriving the correct parameter estimates.

Computer adaptive testing of liability to addiction: identifying individuals at risk.

BACKGROUND Employed as a quantitative measure of substance use disorder (SUD) risk, the transmissible liability index (TLI) can be useful for detecting youths requiring prevention intervention. This study was conducted to develop and evaluate a computer adaptive test (CAT) version of the TLI to identifying individuals at risk for SUD. METHODS In the first sample (N=425) of male and female subjects were recruited under aegis of the Center for Education and Drug Abuse Research in Pittsburgh, PA, USA, having a mean age of 18.8 years. A provisional CAT version of the TLI was assessed using simulation procedures. In sample 2, twins were recruited at the 2010 Twinsburg Festival in Twinsburg, OH, USA. The CAT and paper and pencil (P&P) versions of the TLI were administered to 276 twin pairs having a mean age of 19.94 years. RESULTS The simulated CAT version of the TLI predicted cannabis use disorder 2 years after initial study with 4% less accuracy (72% vs. 68%) than P&P version but with 78% reduction of items. In the twin sample, the CAT version predicted alcohol and drug use (OR=1.7 [2.1], p<.001) with 64% and 65% accuracy (sensitivity=75% [75%] and specificity=64% [65%]). CONCLUSIONS This study demonstrated that the CAT version of the TLI is an accurate and efficient measure of risk for SUD. The CAT version of the TLI potentially affords the opportunity for efficient screening of risk so that timely interventions can be implemented to prevent occurrence of SUDs having frequently lifelong consequences.

Age of Alcohol and Cannabis Use Onset Mediates the Association of Transmissible Risk in Childhood and Development of Alcohol and Cannabis Disorders: Evidence for Common Liability

Age at the time of first alcohol and cannabis use was investigated in relation to a measure of transmissible (intergenerational) risk for addiction in childhood and development of alcohol use disorder (AUD) and cannabis use disorder (CUD). It was hypothesized that age at the time of first experience with either substance mediates the association between transmissible risk and subsequent diagnosis of both disorders. The Transmissible Liability Index (TLI; (Vanyukov et al., 2009) was administered to 339 10- to 12-year-old boys (n = 254) and girls (n = 85). Age at the time of first alcohol and cannabis use, and diagnosis of AUD and CUD, were prospectively tracked to age 22. Each standard deviation unit increase in TLI severity corresponded to a reduction in age of alcohol and cannabis use onset by 3.2 months and 4.6 months, respectively. Age at the time of first alcohol use mediated the association of TLI with both AUD and CUD. Parallel results were obtained for cannabis. Whereas transmissible risk is congenerous to both AUD and CUD, its magnitude was 7 times greater in youths who initiated substance use with cannabis. TLI predicts age of first use of alcohol and cannabis that is common to developing both AUD and CUD. The ramifications of these findings for prevention are discussed.