Susan E Young | University of Colorado School of Medicine (original) (raw)

Papers by Susan E Young

Behavior Genetics, Oct 14, 2016

Developmental Psychology, 2013

Frontiers in Psychiatry, 2011

Journal of Child Psychology and Psychiatry, Jul 2, 2012

Journal of Experimental Psychology: General, May 1, 2008

Infant and Child Development, 2011

The present study examined the role of positive parenting on externalizing behaviours in a longit... more The present study examined the role of positive parenting on externalizing behaviours in a longitudinal, genetically informative sample. It often is assumed that positive parenting prevents behaviour problems in children via an environmentally mediated process. Alternatively, the association may be due to either an evocative gene–environment correlation, in which parents react to children's genetically influenced behaviour in a positive way, or a passive gene–environment correlation, where parents passively transmit a risk environment and the genetic risk factor for the behavioural outcome to their children. The present study estimated the contribution of these processes in the association between positive parenting and children's externalizing behaviour. Positive parenting was assessed via observations at ages 7, 9, 14, 24 and 36 months and externalizing behaviours were assessed through parent report at ages 4, 5, 7, 9, 10, 11 and 12 years. The significant association betwe...

Journal of Abnormal Psychology, Feb 1, 2009

Supplemental material, Friedman_Supplemental_Material for Executive Functions and Impulsivity Are... more Supplemental material, Friedman_Supplemental_Material for Executive Functions and Impulsivity Are Genetically Distinct and Independently Predict Psychopathology: Results From Two Adult Twin Studies by Naomi P. Friedman, Alexander S. Hatoum, Daniel E. Gustavson, Robin P. Corley, John K. Hewitt and Susan E. Young in Clinical Psychological Science

PLOS ONE, Nov 1, 2018

Externalizing problems (EP), including rule-breaking, aggression, and criminal involvement, are h... more Externalizing problems (EP), including rule-breaking, aggression, and criminal involvement, are highly prevalent during adolescence, but the adult outcomes of adolescents exhibiting EP are characterized by heterogeneity. Although many youths' EP subside after adolescence, others' persists into adulthood. Characterizing the development of severe EP is essential to prevention and intervention efforts. Multiple predictors of adult antisocial personality disorder (ASPD) and legal outcomes of a large sample (N = 1205) of clinically-or legally-ascertained adolescents (ages 12-19 years) with severe EP were examined. Many psychosocial predictors hypothesized to predict persistence of EP demonstrated zero-order associations with adult outcomes, but accounted for little unique variation after accounting for baseline conduct disorder symptoms (CD) and demographic factors. Baseline measures of intelligence, which explained independent variation in legal outcomes, provided the only consistent exception to this pattern, though future work is needed to parse these effects from those of socioeconomic factors. CD severity during adolescence is a parsimonious index of liability for persistence of EP into adulthood that explains outcome variance above and beyond all other demographic and psychosocial predictors in this sample.

American Journal of Medical Genetics - Neuropsychiatric Genetics, 2006

Cannabis is a major substance of abuse, and the gene encoding for the central cannabinoid recepto... more Cannabis is a major substance of abuse, and the gene encoding for the central cannabinoid receptor (CNR1) is a logical candidate gene for vulnerability toward developing symptoms of cannabis dependence. We studied four single-nucleotide polymorphisms (SNPs) in the CNR1 gene for association with having one or more symptoms of cannabis dependence in 541 adolescent subjects who had all tried cannabis five or more times. Cases (327) were defined as those who had tried marijuana and developed one or more symptoms, and controls (214) as those who had tried marijuana but developed no dependence symptoms. Cannabis dependence symptoms were assessed in these youth when they were 17 or older with the Composite International Diagnostic Interview-Substance Abuse Module. Univariate (single-marker) association tests demonstrated that SNP rs806380, located in intron 2 of the CNR1 gene, was significantly associated with developing one or more cannabis dependence symptoms, with the G allele having a protective effect (p < 0.02). This was consistent with the results of the global haplotype test (p < 0.01). One of the common haplotypes examined (present in 21% of the subjects) was significantly associated with a lower rate of having one or more cannabis dependence symptoms. Our findings provide evidence suggesting that a common CNR1 haplotype is associated with developing fewer cannabis dependence symptoms among adolescents who have experimented with cannabis.

Drug and Alcohol Dependence, Aug 1, 2004

Substance dependence (SD) and antisocial personality disorder (ASPD) are highly comorbid and aggr... more Substance dependence (SD) and antisocial personality disorder (ASPD) are highly comorbid and aggregate in families. Mating assortment may be an important process contributing to this familial aggregation. Hypothesis: Symptom counts of substance dependence, antisocial personality disorder, and retrospectively assessed conduct disorder (CD) will be correlated significantly among parents of youth in treatment for substance use and conduct problems and, separately, among parents of community controls. Methods: We examined SD, ASPD, and CD among 151 pairs of parents of adolescents in treatment for substance use and conduct problems, and in 206 pairs of parents of control subjects. Results: For average dependence symptoms (ADS) (the sum of across-drug substance dependence symptoms divided by the number of substance categories meeting minimum threshold use) mother-father correlations were 0.40 for patients and 0.28 for controls. Mother-father correlations for ASPD symptom count were 0.33 for patients and 0.26 for controls and for CD symptom count were 0.31 for patients (all P < 0.01) and 0.10 for controls (P = 0.14). Conclusions: Spousal correlations for ADS and ASPD, suggest substantial non-random mating. Results support gender differences in homogamy for SD. Behavior genetic studies of these disorders need to account for assortment to avoid biases in estimates of genetic and environmental effects.

Journal of the American Academy of Child and Adolescent Psychiatry, May 1, 2006

Drug and Alcohol Dependence, Jun 1, 2003

This study describes results from a genome-wide search for quantitative trait loci (QTL) influenc... more This study describes results from a genome-wide search for quantitative trait loci (QTL) influencing substance dependence vulnerability in adolescence. We utilized regression-based multipoint (and single-point) QTL mapping procedures designed for selected sibpair samples. Selected sibling pairs included 250 proband-sibling pairs from 192 families. Clinical probands (13-19 years of age) were drawn from consecutive admissions to substance abuse treatment facilities in the Denver metropolitan area; siblings of probands ranged in age from 12 to 25 years. In addition to the selected sample, a community-based sample of 3676 adolescents and young adults were utilized to define a clinically-significant, heritable, age- and sex-normed index of substance dependence vulnerability-a priori and independent of our linkage results. Siblings and their parents were genotyped for 374 STR micro-satellite markers distributed across the 22 autosomes (average inter-marker distance=9.2 cM). Non-parametric single-point linkage results indicated 17 markers on 11 chromosomes with nominally significant tests of linkage; six markers with LOD scores greater than 1.0 and one marker (D3S1614) with a LOD score of 2.2. Multipoint mapping corroborated two locations and provided preliminary evidence for linkage to regions on chromosome 3q24-25 (near markers D3S1279 and D3S1614) and chromosome 9q34 (near markers D9S1826 and D9S1838).

Behavior Genetics, Apr 18, 2006

Archives of General Psychiatry, Dec 1, 2003

Background: We conducted a sibling/twin/adoption study of substance initiation, use, and problem ... more Background: We conducted a sibling/twin/adoption study of substance initiation, use, and problem use, estimating the relative contribution of genetic and environmental influences on these phenotypes in adolescents. Methods: The participants were 345 monozygotic twin pairs, 337 dizygotic twin pairs, 306 biological sibling pairs, and 74 adoptive sibling pairs assessed by the Colorado Center for the Genetics and Treatment of Antisocial Drug Dependence, Denver and Boulder. The initiation, use, and problem use of tobacco, alcohol, marijuana, and other illicit drugs were assessed. Tetrachoric correlations were computed for each group, and univariate model-fitting analyses were conducted. Results: There were moderate to substantial genetic influences, with the exception of alcohol use and any drug use, and modest to moderate shared environmental influences on substance initiation, use, and problem use. For alcohol and any drug, heritability was higher and the magnitude of shared environmental influences was lower for problem use than for initiation or use. Environmental influences shared only by twin pairs had a significant effect on tobacco initiation, alcohol use, and any drug use. For tobacco use, tobacco problem use, and marijuana initiation, heritability was higher and the magnitude of shared environmental influences was lower in female than in male adolescents. There was no evidence for sex-specific genetic or shared environmental influences on any variable. Conclusions: The moderate to substantial heritabilities found for adolescents in the present study are comparable to those found in twin studies of adult substance use and substance use disorders. The finding that problem use is more heritable than initiation and use is also consistent with the results of adult twin studies. The significance of environmental influences shared only by twin pairs on tobacco initiation, alcohol use, and any drug use suggests the influences of peers, accessibility of substances, and sibling interaction.

Personality and Individual Differences, Jul 1, 1997

The purpose of this study was to assess whether personality dimensions in mothers and in their so... more The purpose of this study was to assess whether personality dimensions in mothers and in their sons predict alcohol and/or substance misuse (ASM) in severely disturbed adolescent boys who were largely from father-absent homes. The sample consisted of 42 adolescent male treatment probands and their mothers. The youths mean age was 15.8 years. All were placed in a residential center and all had conduct disorder diagnosis by DSM III-R criteria. Of the total, 86% met DSM III-R criteria for substance dependence. Alcohol and substance use and criminality were assessed through direct interview, selfreport and family interview. Maternal and adolescent personality dimensions were assessed through an abbreviated version of Cloninger's Tri-Dimensional Personality Questionnaire (TPQ; Cloninger, 1987b). The results indicated that maternal novelty seeking (NS) predicted adolescent alcohol and drug symptoms, but was not significantly related to the mother's own ASM. Probands' NS predicted their own alcohol and drug dependence symptoms. In general, maternal ASM, maternal NS and proband NS all played some role in proband ASM. At the most severe level of adolescent drug dependence, the adolescent's own NS, when coupled with high maternal NS, rendered the youth most vulnerable to increased alcohol and drug dependent symptoms. The assessment of personality dimensions adds new perspectives to the study of families of adolescents with ASM.

American journal of medical genetics, Oct 9, 2000

Comorbidity among childhood disruptive behavioral disorders is commonly reported in both epidemio... more Comorbidity among childhood disruptive behavioral disorders is commonly reported in both epidemiologic and clinical studies. These problems are also associated with early substance use and other markers of behavioral disinhibition. Previous twin research has suggested that much of the covariation between antisocial behavior and alcohol dependence is due to common genetic influences. Similar results have been reported for conduct problems and hyperactivity. For the present study, an adolescent sample consisting of 172 MZ and 162 DZ twin pairs, recruited through the Colorado Twin Registry and the Colorado Longitudinal Twin Study were assessed using standardized psychiatric interviews and personality assessments. DSM-IV symptom counts for conduct disorder and attention deficit hyperactivity disorder, along with a measure of substance experimentation and novelty seeking, were used as indices of a latent behavioral disinhibition trait. A confirmatory factor model fit to individual-level data showed a strong common factor accounting for 16-42% of the observed variance in each measure. A common pathway model evaluating the genetic and environmental architecture of the latent phenotype suggested that behavioral disinhibition is highly heritable (a 2 = 0.84), and is not influenced significantly by shared environmental factors. A residual correlation between conduct disorder and substance experimentation was explained by shared environmental effects, and a residual correlation between attention deficit hyperactivity disorder and novelty seeking was accounted for by genetic dominance. These results suggest that a variety of adolescent problem behaviors may share a common underlying genetic risk.

Drug and Alcohol Dependence, Jun 1, 2007

Objective: Cannabis is the most frequently abused illicit substance among adolescents and young a... more 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: 324 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 12-25 years. A communitybased 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 = 9.2 cM). 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.

American journal of medical genetics, Apr 18, 1997

This study describes results from an ongoing family study of adolescent boys and their families d... more This study describes results from an ongoing family study of adolescent boys and their families designed to investigate potential risk factors for substance abuse. The adolescent treatment probands have severe drug and alcohol related problems and were recruited through a residential rehabilitation program. To date, the sample includes 251 individuals: 39 male probands and their families and 34 control families matched for age and geographic location (zip code). Probands and participating family members are given a structured interview which assesses alcohol and drug problems, and various psychiatric symptoms. The purpose of the present study was to examine the coaggregation of depressive symptoms, antisocial behavior, and alcohol misuse. Multivariate pedigree analyses were performed using a model that allowed for the estimation of vertical familial transmission, residual sibling resemblance, and assortative mating. Spouse correlations were estimated at .57, .21, and .31 for antisocial behavior, depressive symptoms, and alcohol abuse, respectively. Residual sibling environment (i.e., sibling resemblance unaccounted for by parent-offspring transmission) was not found for alcohol problem symptoms, but did contribute to resemblance for antisocial behavior and depressive symptoms. The proportion of variance accounted for by vertical familial transmission was estimated at approximately 30 to 40%. More important, correlations among the transmissible family factors for these psychiatric syndromes ranged from .58 to .73, suggesting substantial overlap among the underlying familial antecedents for these disorders.

Drug and Alcohol Dependence, Feb 1, 2007

Background: Conduct disorder (CD), alcohol dependence (AD), and illicit drug dependence (IDD) fre... more Background: Conduct disorder (CD), alcohol dependence (AD), and illicit drug dependence (IDD) frequently co-occur. This paper describes the result of an investigation of the extent to which comorbid alcohol and illicit drug dependence in adolescents are explained by etiological factors in common with conduct disorder. Methods: Participants were 645 MZ twin pairs, 702 DZ twin pairs, 429 biological sibling pairs, and 96 adoptive sibling pairs, aged 12-18 years, from a community based sample. Conduct disorder was measured using the Diagnostic Interview Schedule for Children-IV. Alcohol and illicit drug dependence were assessed using the Composite International Diagnostic Interview-Substance Abuse Module (CIDI-SAM). For each outcome, subjects were categorized into those with no symptoms, those with one or more symptoms but no diagnosis, and those with a diagnosis. Results: The heritability estimates for CD, AD, and IDD were 58, 66, and 36%, respectively. The genetic correlation between AD and IDD was partially explained by the genetic risk they both share with conduct disorder. Conclusions: We conclude that conduct disorder in adolescents explains, in part, the co-occurrence of alcohol and illicit drug dependence. Specifically, the genetic contribution to their covariation is explained partially by the genetic contribution in common with conduct disorder.