Director's Report to the National Advisory Council on Drug Abuse
February, 1995
Research Findings
Epidemiology, Etiology and Prevention Research
1994 Monitoring the Future Study.
Dr. Lloyd Johnston and his colleagues at the University of Michigan, in their Monitoring the Future study, found that overall, the percentage of young people who report using drugs and/or alcohol is level or increasing. After peaking in 1979, with 60.4 percent of seniors reporting having tried marijuana at least once in their lives, use steadily declined through 1992. An increase in marijuana use was first observed for all three grades in 1993. These earlier increases were confirmed by dramatic increases in use again in 1994. Lifetime use in 1994 was 38.2 percent among seniors and 30.4 percent among tenth graders. For eighth graders, 1994 was the third year of marijuana use increases, rising from 11.2 percent in 1992 to 12.6 percent in 1993 and then to 16.7 percent in 1994. While the sharpest rises in drug use were reported for marijuana use, other substances showed statistically significant increases as well. After remaining level between 1992 and 1993, cocaine use increased among 8th and 10th graders. There were also significant increases observed for hallucinogens, particularly among 10th graders. The most frequently reported hallucinogen is LSD. The percent of students reporting being drunk in the month prior to survey has remained level between 1991 and 1994. However, these rates are very high. Among seniors, 30.8 percent reported being drunk in the past 30 days. For tenth graders, 20.3 percent reported this behavior and among eighth graders, 8.7 percent reported being drunk in the past month. The data collected on students' attitudes related to drug use revealed more bad news for all three grades. This is of major concern because there has been an inverse relationship between the attitude questions and the proportions of students reporting substance since the survey was initiated. In 1994, the proportion of students who perceive risk of harm from use and social disapproval of people who use marijuana substantially declined in all three grade levels. Two measures of high school seniors' attitudes are at the lowest levels since the survey began in 1975 -- the percentage of 12th graders who perceive great risk in trying LSD once or twice and the percentage of seniors who disapprove of people who try LSD. These erosions in attitude are accompanied by more than half of seniors saying it is very or fairly easy to get LSD. Perceived risk associated with experimentation with alcohol, daily drinking, or weekend binge drinking declined in all grades in 1994. Also, students in all grades reported declines in social disapproval of these drinking behaviors.
National Pregnancy and Health Survey.
Data from the National Pregnancy and Health Survey, found that 5.5 percent, or 221,000 of the 4 million women who gave birth in 1992, used some illicit drug during pregnancy. The survey also estimated that the number of babies born to women who used drugs during pregnancy was 222,000 (a number slightly higher than the number of mothers due to multiple live births). These estimates show that, at some time during their pregnancy, 119,000 women (2.9%) reported use of marijuana and 45,000 women (1.1%) reported use of cocaine; the two most frequently used illicit drugs. The survey also found that 757,000 women (18.8%) used alcohol and 820,000 women (20.4%) smoked cigarettes at some time during pregnancy. Only 6% of those who reported no use of any drug used alcohol and cigarettes during pregnancy, while 32% of those who reported use of one drug also smoked cigarettes and drank alcohol. Conversely, of those who reported no use of alcohol or cigarettes, only 0.2% used marijuana, and 0.1% used cocaine. However, of those who reported use of both alcohol and cigarettes, 20.4% also used marijuana, and 9.5% also used cocaine. This has tremendous public health implications and reinforces the need for health practitioners to continually monitor the status of smoking, drinking and illicit/nonmedical drug use during pregnancy. A final report will be available June 1995.
Validity of Illicit Drug Use Reports in Juvenile Arrestees.
Dr. Michael Fendrich and Yanchun Xu have completed a study of over 3,000 juvenile arrestees. Using urine test results as a gold standard, this report evaluates the validity of illicit drug use reports for five illicit substances provided in a multisite, national interview study of the juvenile arrestees. Willingness to report substance use varied according to the type of substance, the time frame for substance use reports, and the characteristics of the juveniles asked to provide the reports. Youth were particularly reluctant to disclose recent use of cocaine and heroin. Race/ethnicity and willingness to disclose other substance use were the most important predictors of cocaine use disclosure among those testing positive for this drug. Race/ethnicity differences in validity were evaluated in the context of other recent epidemiological findings from surveys of drug use in the United States. Implications for the measurement of drug use in criminal justice samples are discussed. Fendrich M, Yanchun X The Validity of Drug Use Reports from Juvenile Arrestees. International Journal of the Addictions, 29(8),971-985,1994.
Consistency in Symptom and Substance Abuse Reporting.
Drs. Michael Fendrich and Virginia Warner have reported on symptom and substance use reporting consistency for offspring at high and low risk for depression. They examined two year recall of reports of lifetime symptomatology and substance use questions on the K-SADS-E in a sample of offspring at high and low risk for depression. Comparisons were made between those who forgot and those who remembered reports of screening symptoms made at the initial interview. In general, recall for symptoms of internalizing disorders (depression and anxiety disorder) was much worse than recall for symptoms of externalizing disorders (conduct disorder and substance use). Less than two-thirds of those initially meeting the lifetime depression screening criteria provided reports which met the lifetime screening criteria at follow up. Significant correlates of screening criteria recall included the following variables (measured at the initial interview): history of treatment for any disorder, impairment on the GAS (a score less than 61), and the presence of hypersomnia and suicidal symptoms (thoughts or ideation). Logistic regression suggested that a prior report of suicidal symptoms (including thoughts, ideation, or behavior) was the most important correlate of screen recall. Fendrich M, Warner V. Symptom and Substance Use Reporting Consistency over Two Years for Offspring at High and Low Risk for Depression. Journal of Abnormal Child Psychology, Vol. 22, No.4, 1994.
Prevention Research
Role of Caffeine in Early Substance Use Onset.
Drs. Linda M. Collins, John W. Graham, and William B. Hansen have just completed a study titled "Does Caffeine Play a Role in Very Early Substance Use Onset? An Illustration of Latent Transition Analysis". This study had two objectives. First it demonstrated the usefulness for prevention research of a relatively new methodology, Latent Transition Analysis (LTA). LTA allows the researcher to estimate and test models of stage-sequential development. Stage sequential models of substance use onset have been investigated in a wide variety of studies. The results indicate that alcohol and tobacco play a role relatively early in the onset process. However, these substances may not initiate the onset process in every case. Another drug that is usually considered harmless, caffeine, is tried by most children before they try either tobacco or alcohol. This study used LTA to examine whether heavy caffeine use played a role very early in the substance use onset process. It was found that children who used large amounts of caffeine were more likely to start the onset process (i.e., begin their substance use experience) before the seventh grade than subjects who used none or moderate amounts. In addition, there was evidence that the early part of the onset process was accelerated for heavy caffeine users. These results suggest that children who use large amounts of caffeine should be watched carefully for signs of increasing substance use. Data came from 4,325 subjects who completed a survey as seventh graders and again one year later as eighth graders. (In press as a chapter in an American Psychological Association Book).
Adolescent Transitions Program.
The Adolescent Transitions Program (ATP), a multicomponent psycho-educational program, was designed to prevent the emergence of problem behaviors in young teens by building both parent and teen skills as well as altering school environments for participating students. A cognitive-behavioral intervention strategy was developed and tested in a clinical setting with parents and teens and was then adapted for implementation within the middle school context. The program consisted of two coordinated interventions, one of which was focused on parents and the other on teens. The basic components of ATP were evaluated using 158 families. Teens recruited were from middle schools and were recruited at the end of the 6th grade school year. Information on program effectiveness was gathered from teens, parents, and teachers. Information included program engagement, skill acquisition, improvement in family interaction, and reductions in problem behavior. Comparisons were made with control families who did not participate. The basic components of ATP were found to be effective in engaging students and their parents, teaching them skills, and improving parent-child relations. The Teen Focus curriculum, while enhancing parent-child relations, did not influence problem behavior in short term evaluations. In fact, teens seemed to escalate in their problem behavior after experiencing the intervention. Although the ATP has proven effectiveness on building individual skills, the efficacy of changing school contexts is being investigated. There is a need to work with schools to change the school environment to (a further increase parent involvement and home-school communication, and b) work to develop more heterogeneous peer environments to counter the effects of deviant peer groups. David W. Andrews, Lawrence H. Soberman and Thomas J. Dishion (Oregon) "The Adolescent Transitions Program: A School-Based Program for High-Risk Teens and Their Parents." Published in Banff Conference for Behavioral Therapy.
Research on Risk/Resiliency Factors
Drs. Lawrence Scheier, Michael Newcomb, and Rodney Skager of the University of California at Los Angeles examined the role of risk and protective factors in predicting teenage drug use (DU) for three age groups separated by gender. Using data from California's biennial survey of students, they applied latent-variable modeling to address the question of how protective factors may inoculate youth from initiating or escalating their DU. A vulnerability latent construct was reflected in three unit-weighted indexes: risk for initiation to DU, risk for problem DU, and protection from DU. A polydrug use construct was reflected in eight measures of alcohol, tobacco, and drug use. Structural equation modeling revealed that, regardless of age and gender, vulnerability was strongly related to polydrug use and other specific DU measures. The number of specific effects between protective factors and DU remained stable with increasing age, although effects between vulnerability and DU were more numerous for 7th and 11th grade students than for 9th grade students. The results underscore two important principles: (1) that DU prevention programs must consider age-related developmental phenomena, and (2) programs should continue to emphasize risk reduction while simultaneously developing and reinforcing protective agents. Scheier, L., Newcomb, M. and Skager, R. Risk, Protection, and Vulnerability to Adolescent Drug Use: Latent-Variable Models of Three Age Groups. Journal of Drug Education, 24(1): 49-82, 1994.
Adolescent Substance Abuse Among Children of Alcoholics (COAs).
Dr. Laurie Chassin and her associates at Arizona State University have investigated factors associated with adolescent substance abuse among children of alcoholics (COAs) and non-COAs. In earlier work, these investigators had found that parental alcoholism affected early adolescent substance use through stress and negative affective mechanisms and through impairments in parental monitoring, both of which increased the probability of associations with peer networks that supported substance use. They also found that parental alcoholism was associated with higher levels of temperamental emotionality in adolescents, which raised the risk of experiencing negative affect. Subsequent investigation using structural equation modeling revealed that parental monitoring and negative affective mechanisms influenced adolescent substance use for both COAs and non-COAs. This finding suggests that programs aimed at teaching coping skills or at improving parental management could be useful regardless of parents' alcoholism history. Molina, B., Chassin, L. and Curran, P. A Comparison of Mechanisms Underlying Substance Use for Early Adolescent Children of Alcoholics and Controls. Journal of Studies on Alcohol, 55(3):269-275, 1994.
Novelty-Seeking, Risk-Taking, and Related Constructs as Predictors of Adolescent Substance Use.
Dr. Thomas Wills and his colleagues tested Cloninger's theory, which posits that substance abuse is related to novelty seeking, harm avoidance, and reward dependence. The investigators used a school-based, self-administered questionnaire (on 7th and 8th grade students) that assessed ten related constructs, including affective states, anger, competence, impulsivity, major negative life events, optimism, self-control, sensation seeking, tolerance for deviance, value on independence/achievement, substance use, and friends' substance use. Cluster analysis identified five groups: (1) "problem teens" characterized by poor self-control; high levels of novelty seeking, risk taking, anger, independence, life events, tolerance for deviance, and negative affect; and low levels of orderliness, achievement orientation, optimism, positive affect, and behavioral competence; (2) "conventional teens," who had opposite levels for all these attributes; (3) "controlled risk-takers," who were high on risk taking and novelty seeking but average on self-control and achievement orientation; (4) "stressed nondeviants," who had average to moderate levels of achievement orientation and self-control but high levels of life events, negative affect, and social anxiety; and (5) "withdrawn youth," who had low levels of both negative and positive characteristics and low levels of peer competence and social orientation. "Problem teens" were found to have the highest levels of substance use and "conventional teens" had the lowest levels. The study findings were interpreted as providing general support for Cloninger's theory but also showing a substantial relationship of substance use to other constructs considered in paradigms such as problem behavior theory, stress-coping theory, and personality models. Wills, T., Vaccaro, D., and McNamara, G. Novelty Seeking, Risk Taking, and Related Constructs as Predictors of Adolescent Substance Use: An Application of Cloninger's Theory. Journal of Substance Abuse, 6(1):1-20, 1994.
Individual, Family, and Peer Risk Factors of Substance Use.
In a prospective longitudinal study conducted at the Center for Education and Drug Abuse Research at the University of Pittsburgh, early onset of alcohol and drug use was investigated among sons of substance-abusing and normal fathers. Hierarchical regression analyses were used to test models to identify risk characteristics associated with sons' perception of family dysfunction, unconventional activities among peers, and affiliation with peers engaged in delinquent behaviors. Logistic regression analyses showed that individual, family, and peer risk factors obtained when the boys were 10-12 years old correctly predicted alcohol and/or drug use by the time the boys were 12-14 years old in 84 percent of cases. The findings support a model of alcohol and drug abuse liability that includes individual, family, and peer risk factors. The findings also suggest that temperament phenotypes influence family interaction patterns, which in turn influence the psychosocial development of the child. Parents tend to take out their anger more often on children with difficult temperaments, and in the presence of a dysfunctional family, high abuse potential and maladaptive discipline practices in parents, children are likely to disengage prematurely from the parental sphere of influence to peer influence. In the presence of conflicted parent-child and sibling relationships, this disengagement from parental influence may increase involvement in unconventional activities among peers, tolerance for deviance, and liability for a host of problems including substance abuse. Blackson, T. and Tarter, R. Individual, Family, and Peer Affiliation Factors Predisposing to Early-Age Onset of Alcohol and Drug Use. Alcoholism: Clinical and Experimental Research, 18(4)813-821, 1994.
Novelty-Seeking Behavior and Dopaminergic Effects.
Dr. Bardo from the University of Kentucky has been involved in exciting research on novelty seeking behavior and dopaminergic effects. Volammetry with electrochemically pretreated carbon fibers is a new technology which provides a distinct signal of catechols with in-vivo implantation. A signal coming from the nucleus accumbens primarily reflects DOPAC, a major dopamine metabolite. The researchers used this technique to assess possible sub-second changes in accumbal dopamine transmission in rats exposed to a novel environment. Following habituation to one compartment of a behavior chamber, rats were allowed to explore an adjacent novel compartment when the partition was removed. All rats either peered into or entered the novel compartment. These behaviors occurred in close temporal association with a marked (more than 70%) but short-lived (less than one minute) rise in the DOPAC signal above the habituated baseline level. Random motor activity in either compartment failed to alter DOPAC, arguing against a simple motor-dependent effect. The authors state that their results add to growing evidence for the involvement of mesolimbic dopamine in novelty-seeking behavior and highlight the value of voltammetric techniques in elucidating this role. G.V. Rebec, C.P. Grabner, R.C. Pierce, M.T. Bardo, "Voltammetry in Freely Moving Rats: Novelty-Dependent Increases in Accumbal DOPAC." Paper presented at the Society for Neuroscience Annual Meeting, Miami Beach, Florida, November 13-18, 1994.
Drugs and Aggression.
While it is widely believed that drugs and violent behavior are associated, it has been difficult to show that drugs actually produce aggression under controlled scientific conditions. A recent study from McLean Hospital in Massachusetts1 showed that athletes reported significantly more fights, verbal aggression and violence toward their wives and significant others during periods in which they were using anabolic-androgenic steroids. A study from the University of Texas Health Science Center2 recently contradicted often-reported findings that marijuana reduces aggressive behavior. When poly-drug users with antisocial personality disorder were studied instead of the usual college students, they increased their aggression toward other laboratory subjects immediately after smoking marijuana. The increased aggression was directly related to the THC content of the marijuana cigarettes.
Victims of criminal aggression and other forms of stress have been found to suffer from a number of behavioral disorders loosely collected under the term "post-traumatic stress disorder". The idea that traumatic stress may bring about drug use in otherwise drug-naive people has been controversial, but has now found some support in the animal laboratory. Researchers at the Louisiana State University Medical Center2 have shown that animals who experience random, unpredictable stress learn to self-administer intravenous cocaine much faster than animals who had some measure of control over their stress experiences.
These studies taken together suggest that aggression and stress may produce drug-taking, and that drug-taking in turn can produce aggression and violence. Further studies will help to identify persons at most risk, and those drugs and drug combinations that produce such dangerous behavioral effects. (1. Choi, P.Y. and Pope, H.G. Jr. Violence toward women and illicit androgenic-anabolic steroid use. Annals of Clinical Psychiatry, 6:21-5, 1994; 2. Cherek, D.R., Roache, J.D., Egli, M., Davis, C., Spiga, R., and Cowan, K. Acute effects of marijuana smoking on aggressive, escape and point-maintained responding of male drug users. Psychopharmacology, 111:163-8, 1993; 3. Goeders, N. E. and Guerin, G.F. Non-contingent electric foot shock facilitates the acquisition of intravenous cocaine self-administration in rats. Psychopharmacology, 114: 63-70, 1994.)
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