Research Findings - Epidemiology and Etiology Research

Community Epidemiology Work Group

The 54th meeting of the Community Epidemiology Work Group (CEWG), chaired by Moira O'Brien, DESPR, was held in St. Louis, Missouri on June 24-27, 2003. The CEWG is composed of researchers from 21 metropolitan areas of the United States who meet semiannually to report on patterns and trends of drug abuse in their respective areas, emerging drugs of abuse, vulnerable populations and factors that may place people at risk of drug abuse and negative health and social consequences. Reports are based on a variety of drug abuse indicator data such as morbidity and mortality information, treatment data and local and State law enforcement data. Additional sources of information include criminal justice, correctional, medical and community health data, local and State survey information, and findings from qualitative research studies.

Polysubstance abuse is proliferating across CEWG areas. The abuse of an array of licit and illicit substances used in a variety of combinations is contributing to emergency department admissions and deaths. DAWN ED estimates for the first half of 2002 show that 71 percent of cocaine mentions represented multidrug episodes, as did 53 percent of the heroin mentions, 74 percent of the marijuana mentions and 54 percent of the methamphetamine mentions. Among DAWN drug-involved death mentions across 20 CEWG areas in 2001, the vast majority of deaths involving cocaine (83 percent), heroin (89 percent), methamphetamine (92 percent) and marijuana mentions (78 percent) involved more than one drug.

Methamphetamine abuse and production continue at high levels in Hawaii, west coast CEWG areas, and some southwestern areas. Abuse and manufacture of methamphetamine continue to move eastward, especially to rural areas. Methamphetamine ED mention rates in the first half of 2002 continued to be highest in west coast areas and parts of the southwest with San Francisco leading with 24 per 100,000 followed by San Diego (11), Phoenix (10), Seattle (9) and Los Angeles (8).

Marijuana indicators were mixed. Rates of marijuana ED mentions increased significantly between the first halves of 2001 and 2002 in Miami, Newark, Phoenix and San Diego but decreased in Chicago, San Francisco and Seattle. Although the proportion of primary marijuana treatment admissions in CEWG areas was high in 2002, there was little change from 2001.

Cocaine/Crack emergency department mention rates in the first half of 2002 were particularly high in Baltimore, Miami, Atlanta, Philadelphia and Chicago ranging between 120 and 140 per 100,000.

Heroin abuse indicators were relatively stable in 2002, but continued at high levels in Boston, Chicago, Detroit, Newark, Philadelphia and San Francisco.

Other Opiate abuse indicators continue to trend upward reflecting the increasing popularity of oxycodone and hydrocodone products reported by several CEWG members. Oxycodone ED mentions increased 110 percent between the first halves of 2001 and 2002 in San Francisco where ethnographic observers concurred that the use of oxycodone is on the rise. Hydrocodone ED mentioned increased nearly 79 percent between the first halves of 2001 and 2002 in Minneapolis/ St. Paul.

MDMA (methylenedioxymethamphetamine) indicators are stable or declining in most CEWG areas. MDMA ED mentions decreased in 11 CEWG areas from the first and/or second half of 2001 to the first half of 2002, with a significant increase reported only in New Orleans. The highest number of MDMA ED mentions in the first half of 2002 were in Philadelphia, Miami, San Francisco, Atlanta, Los Angeles and New York City.

Phencyclidine (PCP) indicators increased in five CEWG areas: Los Angeles, Philadelphia, Phoenix, Washington, D.C. and Texas. In Washington D.C., criminal justice sources report an increase in PCP availability and use. In Los Angeles, there was an 11 percent increase in PCP-related arrests from 2001 to 2002.

Lysergic Acid Diethylamide (LSD) indicators have been declining sharply in most CEWG areas. This is consistent with the declines in prevalence of LSD use reported by the most recent national surveys, the Monitoring the Future study (2002) and Household Survey on Drug Abuse (2001).

Student Drug Testing and Rates of Illicit Drug Use

Investigators at the University of Michigan conducted a study of the association between school drug testing practices and rates of drug use. They combined data from the 1998 through 2001 Monitoring the Future surveys, yielding a base of around 30,000 8th grade students in 260 schools, 23,000 10th grade students in 227 high schools, and 23,000 12th grade students in 235 high schools from across the nation. School drug testing policies and practices were determined from questionnaires administered to school administrators, and student drug use was ascertained from self-administered questionnaires. At each grade level studied, the investigators found virtually identical rates of drug use in the schools that have drug testing and the schools that do not. For example, in 12th grade, 36% of those in non-testing schools reported having used marijuana in the twelve months prior to the survey, versus 37% in the schools that did test. Additional analyses showed that in high schools that tested athletes, marijuana and other drug use by male athletes was not significantly different from use among male athletes in the great majority of high schools that do not test their athletes. The authors acknowledge that with only cross-sectional data they could not make definitive causal interpretations regarding the effects of drug testing; it is conceivable, for example, that the schools that instituted drug testing initially had higher use, and that drug testing reduced those levels. While the results are not conclusive, they indicate a lack of evidence for a preventive effect from student drug testing as it is commonly practiced. Yamaguchi, R., Johnston, L.D., and O'Malley, P.M. The Relationship Between Student Illicit Drug Use and School Drug-Testing Policies. Journal of School Health, 73(4), pp. 159-164, 2003.

Genetic and Environmental Factors for Drug Use Disorders in Males

This study examines whether genetic and shared environmental risk factors for substance use disorders render individuals vulnerable to use of specific substances or to substance use and related disorders in general. Data for this population-based study comes from interviews with 1196 male twin pairs determined by birth registry. Six categories of drug use and abuse/dependence were included in the models: cannabis, cocaine, hallucinogens, sedatives, stimulants, and opiates. Several important findings were reported. First, it appears from these models that one common genetic factor strongly influences the risk for both use and abuse/dependence for all substances; that is, individuals appear to be genetically vulnerable to drug abuse in general, rather than to a specific drug. This has important implications for efforts to locate genes for drug abuse vulnerability. Second, shared environmental influences also appeared largely non-specific; thus, family or peer environmental factors do not appear strongly determinative of which drug an individual uses or becomes dependent on. Third, it then appears that an individual's personal (non-shared environmental) experiences are largely responsible for determining which drug an individual uses. Both of these latter points have important implications for preventive interventions. Kendler, K.S., Jacobson, K.C., Prescott, C.A. and Neale, M.C. Specificity of Genetic and Environmental Risk Factors for Use and Abuse/Dependence of Cannabis, Cocaine, Hallucinogens, Sedatives, Stimulants, and Opiates in Male Twins. American Journal of Psychiatry, 160, pp. 687-695, 2003.

Neurobehavioral Disinhibition in Childhood Predicts Substance Use Disorder

This longitudinal study determines the extent to which boys at high-average-risk (n=47) and low-average-risk (n=65) for substance use disorder (based upon family-history of illicit drug abuse) differ on a construct of neurobehavioral disinhibition (based upon measures of affect, behavior, and neurocognition), evaluates the capacity of neurobehavioral disinhibition to predict substance use frequency at age 16, and demonstrates the utility of neurobehavioral disinhibition in predicting substance use disorder at age 19. The neurobehavioral disinhibition score significantly discriminated boys at high average risk from those at low average risk at ages 10-12. Neurobehavioral disinhibition at age 16, in conjunction with substance use frequency and risk status group, predicted substance use disorder at age 19 with 85% accuracy and accounted for 50% of the variance in Drug Use Screening Inventory overall problem density score. Neurobehavioral disinhibition was a stronger predictor of substance use disorder (odds ratio = 6.8) than substance consumption frequency (odds ratio = 3.2). Results are consistent with the notion that neurobehavioral disinhibition is a component of a liability to develop substance use disorder. Tarter, R.E., Kirisci, L., Mezzich, A., Cornelius, J.R., Pajer, K., Vanyukov, M., Gardner, W., Blackson, T. and Clark, D. Neurobehavioral Disinhibition in Childhood Predicts Early Age At Onset of Substance Use Disorder. American Journal of Psychiatry, 160(6), pp. 1078-1085, 2003.

A Twin Study of Neuropsychological Consequences of Stimulant Abuse

Previous studies document neuropsychological deficits associated with stimulant abuse, but findings are inconsistent. This study identified 50 twin pairs (aged 40-51 yrs) in which only 1 member had heavy stimulant abuse (cocaine and/or amphetamines) ending at least 1 year before the evaluation. Subjects were administered an extensive neuropsychological test battery organized into the following 5 functions: attention, executive functioning, motor skills, intelligence, and memory. Multivariate tests showed that abusers performed significantly worse than nonabusers on functions of attention and motor skills. Within each of these functions, univariate tests showed that abusers performed significantly worse on certain tests of motor skills and attention. In contrast, abusers performed significantly better on one test of attention measuring visual vigilance. Within the abuser group, higher levels of stimulant use were largely uncorrelated with neuropsychological test scores, although a few significant correlations indicated better functioning with more stimulant use. This study demonstrates that deficits in attention and motor skills persist after 1 year of abstinence from stimulant use and raises hypotheses regarding relative strengths on a vigilance task among abusers. Toomey, R., Lyons, M.J., Eisen, S.A., Xian, H., Chantarujikapong, S., Seidman, L.J., Faraone, S.V. and Tsuang, M.T. A Twin Study of Neuropsychological Consequences of Stimulant Abuse. Archives of General Psychiatry, 60(3), pp. 303-310, 2003.

Parent-Child Conflict and Childhood Externalizing Disorders

The authors sought to examine the relationship between parent-child conflict and externalizing disorders (attention deficit-hyperactivity disorder, or ADHD, oppositional defiant disorder, or ODD, and conduct disorder, or CD), which can confer increased risk for later substance use disorders. Data were gathered from 808 same-sex 11-year-old twin pairs from a population-based sample, and their mothers. Resulting models suggest that parent-child conflict acts as a common factor increasing vulnerability for multiple childhood disorders. This offers an important target for preventive interventions, perhaps of multiple disorders. Moreover, analyses found that common genetic and environmental factors appear to underlie the externalizing childhood disorders and the parent-child conflict. Thus, such genetically-informed studies can help disentangle genetic and environmental influences, and clarify productive preventive approaches. Burt, A., Krueger, R.F., McGue, M., and Iacono, W. Parent-Child Conflict and the Comorbidity Among Childhood Externalizing Disorders. Archives of General Psychiatry, 60, pp. 505-513, 2003.

Heterogeneity in Progression from Abuse to Dependence

The purpose of this study was to examine progression from drug abuse to drug dependence across alcohol, cannabis, cocaine, and opiates. Retrospective data were reanalyzed from the DSM-IV Substance Use Disorders Working Group. Participants (n=1,226) were interviewed with the Composite International Diagnostic Interview-Substance Abuse Module. Results consistently suggest that a progression generally occurs from abuse to dependence for alcohol and cannabis, but not for cocaine or opiates. Regarding the timing of onset of abuse/dependence, cocaine and opiate use disorders onset closely in time irrespective of the length of time from first use. Moreover, more cocaine users experienced a disorder (85%) compared to users of cannabis (58%) or opiates (64%). Results suggest considerable heterogeneity in the course of drug disorders, and highlight the need for more research on nosologic, environmental, and genetic contributions to the transitions to dependence. Ridenour, T.A., Cottler, L.B., Compton, W.M., Spitznagel, E.L. and Cunningham-Williams, R.M. Is There a Progression from Abuse Disorders to Dependence Disorders? Addiction, 98, pp. 635-644, 2003.

HIV and AIDS Risk Behaviors in Juvenile Detainees

Detained youth may be at especially high risk for contracting HIV and AIDS. This study reports on the rates of HIV and AIDS sexual and drug risk behaviors among a group of juvenile detainees participating in the Northwestern Juvenile Project. Participants in this longitudinal study included 1829 youth (age 10-18) initially arrested and detained between 1995 and 1998 at the Cook County Juvenile Temporary Detention Center in Chicago, Ill. The random sample was stratified by gender, race/ethnicity, age, and charge severity. Information related to HIV and AIDS risk behavior was collected on 800 participants from the larger study. Results indicate 95% of the detained youth report engaging in 3 or more sexual and drug risk behaviors, and 65% report engaging in 10 or more risk behaviors. More than 90% of the males were sexually active; 61% had more than one sexual partner in the last three months. Significantly more males than females report engaging in the sexual risk behaviors examined in this study. No significant gender differences were found in the self-report data related to drug risk behaviors. Regarding race/ethnicity: African American males report engaging in significantly more sexual risk behaviors, although non-Hispanic Whites and Hispanics report participating in more drug risk behaviors. Among females, significantly more non-Hispanic Whites than African Americans or Hispanics report engaging in sexual risk behaviors, while Non-Hispanic Whites and Hispanics report participating in more drug risk behaviors. Over 50% of juveniles age 10-13 report engaging in both sexual and drug risk behaviors. These findings highlight the importance of developing effective sexual and drug-related HIV/AIDS risk reduction interventions for youth in the juvenile justice system. Teplin, L.A., Mericle, A.M., McCelland, G.M., and Abram, K.M. HIV and AIDS Risk Behaviors in Juvenile Detainees: Implications for Public Health Policy. American Journal of Public Health, 93(6), pp. 906-912, 2003.

Race/Ethnic Differences in the Effects of Cumulative Adversity on Drug Dependence in Young Adults

This study assesses the effects of cumulative exposure to stressors as a risk factor for drug dependence, and evaluates whether race/ethnic differences in exposure to stressful events contributes to race/ethnic differences in prevalence of drug dependence. Data were analyzed cross-sectionally from a community survey of lifetime adverse experiences and substance and psychiatric disorders among young adults. Data were collected between 1997-2000 in Miami-Dade County, Florida. The sample size is 1,803 former Miami-Dade Public School students, 93% of whom were between ages 19 and 21 when interviewed. Males and females of Cuban origin, other Caribbean basin Hispanics, African-Americans, and non-Hispanic Whites are equally represented. Drug dependence disorder was assessed by DSM-IV criteria using the Composite International Diagnostic Interview, and a 41-item checklist of lifetime exposure to major and potentially traumatic experiences were used to measure cumulative adversity. Both measures include age at time of first occurrence. The lifetime rate of drug dependence disorder (total 14.3%) did not vary significantly (p>.05) by socioeconomic group. The rate for males (17.6%) was significantly greater than female rate (10.9%). The African-American rate (6.5%) was dramatically lower than non-Hispanic White (17.0%), Cuban (18.1%) and non-Cuban Hispanic (16.0%) rates despite their dramatically higher exposure to adversity. Twenty eight of 33 individual adversities were associated with the subsequent onset of drug dependence (p<.05). Cumulative lifetime exposure was greatest for males and for African-Americans, and was inversely associated with socioeconomic level. Multivariate discrete-time event history analysis revealed significant independent effects of distal (>1 year earlier) and proximal (previous year) exposure to adverse events (p<.05), controlling for childhood conduct disorder, ADHD, and prior psychiatric disorder. Lifetime cumulative exposure to distant as well as more recent adversity predicts risk of subsequent drug dependence, though it does not explain ethnic group differences in risk. Implications are that distal and proximal stressful events should both be included when measuring stress exposure. Turner, R.J. and Lloyd, D. Cumulative Adversity and Drug Dependence in Young Adults: Racial/Ethnic Contrasts. Addiction, 98, pp. 305-315, 2003.

The Deterrence Hypothesis Reexamined: Sports Participation and Substance Use Among Young Adults

The widely held notion that sports participation reduces subsequent risk of substance use is evaluated with longitudinal survey data of a representative sample of 1,172 youth when they were in their preteen and young adult years. Unlike previous inquiries into the deterrence hypothesis, the present study controls for other major factors previously found to be predictive of alcohol and drug use, such as family structure and stress exposure. Results of analyses revealed that contrary to the deterrence hypothesis, playing high school sports does not appear to be a protective factor that lowers one's involvement in young adult alcohol or drug use--with one exception. Subgroup analyses revealed that among blacks, the greater the extent of high school sports participation the less the risk of substance use. In direct contradiction to the deterrence hypothesis, playing high school sports was found to be positively associated with alcohol use for whites, even in the context of other major predictors of alcohol use. Further analyses revealed that the positive association between sports participation and alcohol use appeared to exist only for white males. These findings cast doubt about the contention that playing high school sports is protective against alcohol and illegal substance use. Eitle, D., Turner, R.J. and McNulty Eitle, T. The Deterrence Hypothesis Reexamined: Sports Participation and Substance Use Among Young Adults. Journal of Drug Issues, 33, pp. 193-222, 2003.

Maternal Correlates of Toddler Insecure and Dependent Behavior

The present study was designed to examine the relationship between characteristics of mothers' and toddlers' insecure and dependent behavior. Two hundred fifty-four 2-year-old toddlers and their mothers were studied using a structured questionnaire administered to the mothers in their homes. The extent to which insecure and dependent behavior is related to the domains of maternal personality traits, maternal drug use, maternal child rearing, and parental marital relations was assessed. Using Pearson correlations and hierarchical multiple regression analyses, the maternal child-rearing and maternal personality domains were found to have a direct effect on the toddlers' insecure and dependent behavior. The maternal child-rearing domain also served as a mediator for the domains of the parents marital/partner relations, maternal personality attributes, and maternal drug use. There was also evidence suggesting an indirect effect of maternal personality attributes on the toddlers insecure and dependent behavior, which is mediated by the domain of maternal child-rearing practices. Implications for the prevention of insecure and dependent behavior in toddlers are discussed. Brook, J.S., Brook, D.W., and Whiteman, M. Maternal Correlates of Toddler Insecure and Dependent Behavior. Journal of Genetic Psychology, 164(1), pp.72-87, 2003.

BIS/BAS Levels and Psychiatric Disorder: An Epidemiological Study

Behavioral inhibition and behavioral activation levels have been theorized to relate to a broad range of psychopathologies. To date, however, studies have focused on a single diagnosis, and the measures used to assess different psychopathologies have varied greatly. This study assessed how levels of behavioral inhibition and behavioral activation relate to lifetime diagnoses of depression, anxiety, drug abuse and dependence, alcohol abuse and dependence, attention deficit hyperactivity disorder, and conduct disorder. A representative community sample of 1,803 individuals between the ages of 19 and 21 in the Miami area was surveyed with the Composite International Diagnostic Interview and the Behavioral Inhibition and Behavioral Activation Scales (BIS/BAS; Carver & White, 1994). Results supported the role of BIS as a vulnerability factor for depression and anxiety and for BAS Fun-Seeking for drug abuse and non-comorbid alcohol diagnoses. Goals in understanding BIS and BAS are described, including the need for prospective studies with a broader array of behavioral indices. Johnson, S.L., Turner, R.J. and Iwata, N. BIS/BAS Levels and Psychiatric Disorder: An Epidemiological Study. Journal of Psychopathology and Behavioral Assessment, 25, pp. 25-36, 2003.

Protective Effect of Social Self-Efficacy on the Link between Maltreatment and Internalizing Problems

Antisocial Behavior Impairs Emotion Regulation among Cocaine-Using Women

This study examined the relation between deficits in affect regulation and adult antisocial behavior (ASB) in a sample of 80 inner-city crack/cocaine-using women. Retrospective narrative early memories were coded for two components of affect regulation, affect tolerance and affect expression, using the Epigenetic Assessment Rating Scale. Analyses compared the affect regulation measures among primary crack/cocaine-using women with and without ASB, as measured by the adult criteria of antisocial personality disorder. Findings revealed that women with ASB had significantly poorer capacity for affect tolerance and affect expression than women without ASB. Litt, L.C., Hien, D.A.and Levin, D. Psychology of Women Quarterly, 27(2), pp. 143-152, 2003.

Emotion-Focused Coping as a Mediator of Maternal Cocaine Abuse and Antisocial Behavior

This study examined the links between maternal drug use and antisocial behavior in a case-control study of 279 inner-city mothers in 3 comparison groups: drug abusers, (n = 112), depressed mothers (n = 73), and nonsubstance abusing controls (n = 94). Using hierarchical regression techniques and mediational analyses controlling for ethnicity, current depression, and family history of substance abuse, support was provided for an emotion-focused coping style as a link between addictive and antisocial behavior. These results highlight the importance of focusing on emotion regulation models in the prevention and treatment of violence in drug-abusing women. Hien, D.A. and Miele, G.M. Emotion-Focused Coping as a Mediator of Maternal Cocaine Abuse and Antisocial Behavior. Psychology of Addictive Behaviors, 17(1), pp. 49-55, 2003.

The Validity of Analyses Testing the Etiology of Comorbidity between Two Disorders: A Review of Family Studies

This study examined the validity of family prevalence analyses in testing alternative comorbidity models. Across 42 family studies, three comorbidity models were tested: the alternate forms model, the correlated liabilities model, or the three independent disorders model. Results from data simulations suggest that some analyses may be valid tests of the alternate forms model (i.e., two disorders are alternate manifestations of a single liability), but that none of the analyses are valid tests of the correlated liabilities model (i.e., a significant correlation between the risk factors for the two disorders) or the three independent disorders model (i.e., the comorbid disorder is a third, independent disorder). Rhee, S.H., Hewitt, J.K., Corley, R.P. and Stallings, M.C. The Validity of Analyses Testing the Etiology of Comorbidity between Two Disorders: A Review of Family Studies. Journal of Child Psychology & Psychiatry and Allied Disciplines, 44(4), pp. 612-636, 2003.

Buffering Effects of Religiosity on Substance Use

This research tested the hypothesis that religiosity buffers the impact of life stress on adolescent substance use. Data were from a sample of 1,182 participants surveyed on 4 occasions between 7th grade and 10th grade. Cross-sectional results showed an inverse relation between religiosity and substance use (cigarette smoking, alcohol use, heavy drinking, marijuana use). Longitudinal analyses using latent growth modeling indicated that the impact of negative life events on both initial level of substance use and rate of growth in substance use was reduced among individuals scoring high on religiosity. Wills, T.A., Yaeger, A.M., and Sandy, J.M. Buffering Effect of Religiosity for Adolescent Substance Use. Psychology of Addictive Behaviors, 17, pp. 24-31, 2003.