Genetic approaches to understanding the actions of drugs of abuse.
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Animals↗
Biomedical subjects
R W Pickens
Publications and source records attributed to R W Pickens.
Substance use risk factors for HIV infection.
The focus on reducing needle sharing by IVDUs as an HIV-control strategy is well supported by epidemiologic data. Because of this emphasis, however, the role of other HIV risk factors in drug use is sometimes overlooked. Although needle sharing by IVDUs undoubtedly will continue to be one of the greatest risk factor for HIV infection in drug users, other risk factors in HIV infection also are associated with drug use and may contribute significantly to the spread of HIV infection. It is clear that the role of drug use in AIDS is not limited to needle sharing by IVDUs. HIV infection can be transmitted by any type of needle use. Nonintravenous drugs (e.g., crack) and other risk factors (e.g., unprotected sex) also may play a role in the spread of HIV infection. Because of its dependence potential, crack may come to play a major role in HIV transmission, primarily because of its link to unprotected sexual behavior.
HIV Infections↗
Craving: consensus of status and agenda for future research.
The term craving is used frequently in relationship to drug abuse and its treatment but there is disagreement over its definition and role. In February 1991, a meeting of experts from several disciplines, sponsored by the Addiction Research Center (ARC) of the National Institute on Drug Abuse, was convened with the goal of reaching consensus about the importance of craving and to suggest a future research program. The participants agreed that craving is a subjective state in humans that is associated with drug dependence but little is known about its determinants, relationship to drug taking, and measurement. To advance our knowledge, a substantial research program is required. The outcome of this research effort could have important consequences for increasing our understanding of the determinants of drug abuse.
Humans↗
Sex and age effects on the inheritance of alcohol problems: a twin study.
Male monozygotic cotwins of probands with Alcohol Abuse-Dependence (n = 85) were more likely than male same-sex dizygotic cotwins (n = 96) to report alcohol, drug, and conduct disorder problems. For women, rates of problem behavior did not differ between monozygotic (n = 44) and same-sex dizygotic (n = 43) cotwins. Opposite-sex dizygotic twin data (n = 88) revealed significant cross-sex transmission; alcohol problems were greatest among male cotwins of female probands. For men, proportion of liability variance associated with additive genetic factors was significantly greater when proband had an early (h2 = .73 +/- .18) rather than late (h2 = .30 +/- .26) age of onset. For women, heritability did not vary as a function of proband's age of onset, and the pooled estimate suggested little genetic influence (h2 = .00, SE not computable). Findings suggest that genetic influences may be substantial only in the etiology of early-onset male alcoholism.
Adult↗
Age at first injection and HIV risk among intravenous drug users.
The relationship of age at first injection and HIV risk was explored in a nonblinded HIV seroprevalence study of intravenous drug users (IVDUs) admitted to methadone treatment in seven United States cities between February 1987 and June 1989. Comparisons were made of IVDUs who began injecting as adolescents, young adults, and adults in terms of drug use and sexual HIV risk behaviors and HIV serostatus. Early injectors consistently reported higher levels of drug-using risk behaviors (e.g., frequency of injection, frequency of needle sharing, and use of shooting galleries), and were more likely to be HIV seropositive. Among females, early injectors were also more likely to report sexual risk behaviors (e.g., multiple sex partners, prostitution). The relationship of age at first injection with selected risk behaviors and HIV serostatus was independent of subjects' age at interview, gender, and race/ethnicity. This study suggests that adolescent injectors are an important target group for HIV prevention efforts.
Adolescent↗
Recommendations for improving drug treatment.
Recognizing that drug use is both chronic and relapsing once an individual is addicted, and that treatment is effective in reducing drug use/misuse, improving drug misuse treatment is examined and research as well as practice recommendations are presented. Drug misuse treatment is now recognized in the United States to meet the expanding drug use problem and for reducing the spread of HIV. With that background, the current status of drug misuse treatment is reviewed, clinical issues are emphasized, and policy issues are noted. Recommendations include the need for uniform funding, linkage with community agencies, technology transfer, training, and expanding research and evaluation efforts.
HIV Infections↗
Heterogeneity in the inheritance of alcoholism. A study of male and female twins.
Genetic influence on risk for alcoholism was examined in a US treatment sample of 50 monozygotic (MZ) and 64 dizygotic (DZ) male and 31 MZ and 24 DZ female same-sex twin pairs. For the DSM-III composite diagnosis of Alcohol Abuse and/or Dependence, statistically significant MZ/DZ differences in concordance were found with male, but not female, twins. For specific diagnoses, MZ/DZ differences were found in male subjects for both Alcohol Abuse and Alcohol Dependence, while MZ/DZ differences in female subjects were found only for Alcohol Dependence. The male MZ/DZ concordance difference for composite diagnosis but not for Alcohol Dependence could be accounted for statistically by differences in age of onset between MZ and DZ probands. As with alcohol, differences in MZ/DZ concordance were found for DSM-III composite diagnoses of Other Substance Abuse and/or Dependence with male, but not female, twins. Using Epidemiological Catchment Area data to estimate the population base rates of both alcohol and other substance use disorders allowed for heritability analyses that showed genetic factors to have only a modest influence on overall risk in both sexes (heritability estimates of approximately 0.35 for male subjects and 0.24 for female subjects). However, evidence for heterogeneity in the pattern of inheritance was also found, suggesting forms of alcoholism that may be moderately to highly heritable.
Age Factors↗
Genetic influences in human substance abuse.
The importance of clinical studies to genetic research on substance abuse is discussed. This paper compares the advantages and limitations of methods employed in clinical studies to those employed in animal studies. It stresses the complementary nature of human and animal studies for improving our understanding of genetic influences in substance abuse. Finally, it reviews findings from adoption and twin studies of substance abuse. Whereas much is known about genetic influences in human alcoholism, relatively little is known about genetic influences in other types of drug abuse. This disparity is directly related to the amount of research that has been conducted in the two areas over the past several years.
Adoption↗
Methodological issues in genetic studies of human substance abuse.
This paper described a number of critical assumptions and methodological issues that influence the interpretation of data from family, twin and adoption studies of substance abuse. Also, using data from a recent study, it examined the role of one methodological issue (method of zygosity determination) and one critical assumption (representativeness of twins as research subjects) to determine the validity of data in twin studies of substance abuse. The accuracy of the questionnaire methods for zygosity determination in alcoholic twins was similar to that previously reported for nonalcoholic twins. Also, alcoholic twins were found to be representative of both nonalcoholic twins and alcoholics in general.
Alcoholism↗
HIV infection and AIDS risk behaviors among intravenous drug users entering methadone treatment in selected U.S. cities.
To assess trends in HIV infection and AIDS risk behaviors among intravenous drug users (IVDUs), a series of nonblinded point-prevalence surveys was conducted with admissions to methadone treatment in seven areas, including New York City; Trenton and Asbury Park, New Jersey; Baltimore; Chicago; San Antonio, Texas; and Los Angeles County between February and December 1987 (n = 713), January and June 1988 (n = 1,089), July and December 1988 (n = 932), and January and June 1989 (n = 1,110). Over the 2-year period, significant changes in HIV seropositivity levels were found in only one of the seven cities (Chicago, with levels increasing from 8.4 to 14.7%). High levels of AIDS risk behaviors (frequency of injection, needle sharing, needle cleaning, and use of shooting galleries) were found in all cities. Comparisons of trends in recent risk behaviors (past year) within cities suggest that relatively little reduction in AIDS risk behaviors had occurred during the study.
Acquired Immunodeficiency Syndrome↗
Improving drug abuse treatment. Overview of treatment issues.
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Humans↗
Improving drug abuse treatment: recommendations for research and practice.
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Humans↗
The relationship between chronic ethanol exposure and cigarette smoking in the laboratory and the natural environment.
Few studies have examined the association between ethanol use and cigarette smoking topography. In particular, no study has objectively investigated the relationship between chronic ethanol exposure and cigarette smoking. The aim of this study was to quantify the relationship between cigarette smoking and past and current ethanol use. Male and female cigarette smokers (n = 77) between the ages of 30 and 65 years were recruited and grouped as a function of their past and current ethanol use. Group 1 (n = 18) included subjects who were ethanol abstinent for the 3 months prior to the study and had no history of alcohol abuse (as defined by DSM-III criteria). Group 2 (n = 19) included subjects who were current regular ethanol users and had no history of alcohol abuse. Group 3 (n = 20) included subjects who were ethanol abstinent and had a history of alcohol abuse. Group 4 (n = 20) included current regular ethanol users with a history of alcohol abuse. A history of alcohol abuse was associated with an intensified pattern of cigarette smoking. Significant differences were observed for total daily smoke exposure, cigarette number, puff number, total puff and inhalation volume, and the nicotine, tar and carbon monoxide yields of the cigarettes smoked. Increased expired-air carbon monoxide and serum cotinine levels were also observed. Current ethanol use was not associated with an increased cigarette smoking pattern. These data suggest that alcohol abusers are at greater risk of contracting cigarette-related pathology.
Adult↗
Situational factors in cigarette smoking.
Situational factors related to smoking behavior in the natural environment were studied. Six subjects smoked all cigarettes over 10 days with a portable, electronic recording device which measured a number of frequency and time-based features of smoking. Subjects also coded activities and internal states associated with each cigarette smoked. Across subjects, there were considerable differences in the distribution of cigarettes smoked across the activity and internal states categories. Within subjects, all subjects showed variation in measures of smoking topography (number of puffs/cigarette, mean puff duration, total puff time/cigarette) as a function of situational variables. It did not appear that pharmacological factors could fully account for the substantial situational differences found. The results suggest that different factors may be involved in the control of different aspects of smoking topography.
Adolescent↗
Heterosexual transmission of human immunodeficiency virus among intravenous drug users.
To examine sexual transmission of human immunodeficiency virus (HIV) among heterosexual intravenous drug users (IVDUs), HIV antibody status of IVDUs with intravenous drug-using sexual partners (IVSPs) was compared with that of IVDUs with no IVSPs. Initial bivariate analyses indicated IVDUs with IVSPs were more likely to be HIV antibody-positive than those with no IVSPs. Analyses by gender indicated that this relationship held for men but not women. IVDUs with IVSPs also differed from those without IVSPs demographically, in drug use, and in other sexual behaviors. When effects of other variables were controlled, no statistically significant relationship was found between injection history of sex partners and HIV status for the total sample or separately for men or women.
Adult↗
Introduction of HIV infection among intravenous drug abusers in low prevalence areas.
To explore the introduction of human immunodeficiency virus (HIV) infection into intravenous drug abusing populations, risk behaviors of 1,154 intravenous drug abusers (IVDAs) in four U.S. cities with low prevalence of IVDA/HIV infection (0.9-13.0%) were examined. Seropositive subjects (N = 54) were compared with demographically matched seronegative controls regarding drug use practices, homosexual contact, blood transfusions, risk behaviors while traveling or living in high prevalence areas, and acquaintance with persons with AIDS. With the exception of needle sharing with homosexual/bisexual males, no differences in risk behaviors were found between seropositive subjects and matched seronegatives. Seropositives were substantially more likely than matched seronegatives to report having shared a needle with a homosexual or bisexual male, suggesting that needle sharing between homosexual/bisexual IVDAs and heterosexual IVDAs may be an important means by which HIV is introduced among heterosexual IVDAs in low prevalence areas.
Adult↗
Smoking topography and nicotine blood levels.
Frequency and durational components of smoking topography were measured by a portable smoking device while 10 subjects smoked four cigarettes ad libitum in a non-laboratory environment. Nicotine blood levels were measured before and after smoking each cigarette and serial blood samples for determining nicotine metabolic half-life were obtained the following day. Results showed that change in pre- and post-cigarette nicotine levels and metabolic half-life for nicotine were not related to within-cigarette topography measures or nicotine yield of cigarette, but were significantly related to intercigarette interval.
Adult↗
The acquired immunodeficiency syndrome and intravenous drug abuse.
Intravenous drug abusers constitute 25 per cent of the cases of the acquired immunodeficiency syndrome (AIDS) in adults in the United States of America and 21 per cent of such cases in Europe. The potential for the rapid spread of the human immunodeficiency virus (HIV) among intravenous drug abusers exists because such drug abusers commonly share drug injection equipment. The heterosexual and perinatal spread of AIDS is also largely associated with intravenous drug abusers, and drug abusers have been identified as a major vector for the spread of the AIDS epidemic as it is associated with intravenous drug abuse. As long as intravenous drug abusers are addicted, they will continue to be at risk of contracting AIDS. Thus, the primary AIDS prevention strategy must be to help addicts to stop using drugs. It is suggested that drug abuse treatment resources should be expanded and outreach programmes developed to encourage more intravenous drug abusers to enter treatment. AIDS risk-reduction counseling must also be provided to intravenous drug abusers who continue injecting drugs, and to addicts and their sexual partners to prevent the sexual spread of HIV. Vigorous AIDS prevention initiatives must be undertaken now, using the most promising intervention strategies, while simultaneously evaluating and refining these strategies.
Acquired Immunodeficiency Syndrome↗