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National Institute on Drug Abuse
Women and Sex/Gender Differences Research
Director's Report to Council
Research Findings Excerpts
May, 2001
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Behavioral Research |
Motivation to Obtain Nicotine Is Higher in Female Rats
Research on smoking behavior and responsiveness to nicotine suggests that nicotine's effects may depend on the sex of the organism. Researchers in the Department of Psychology, University of Pittsburgh, led by Dr. Anthony R. Caggiula allowed male and female rats to self-administer nicotine at one of four doses (0.02-0.09 mg/kg, free base) on both fixed and progressive ratio schedules of reinforcement. Progressive ratio schedules measure how much an animal will work to obtain reinforcement - an infusion of nicotine in this case. Males and females acquired nicotine self-administration across the entire range of doses. Acquisition of self-administration at the lowest dose was faster in females than males. However, few sex differences were found in the number of active responses, number of infusions, or total intake of nicotine during stable fixed ratio self-administration. In contrast, females reached higher break points on the progressive ratio; that is, they worked harder than the males to obtain the same dose of nicotine. For both schedules, females had shorter latencies to earn their first infusion of each session and demonstrated higher rates of both inactive and timeout responding. There was no effect of estrous cycle on self-administration during either fixed or progressive ratio sessions. Self-administered nicotine resulted in average arterial plasma nicotine levels between 53 and 193 ng/ml and left hemi-brain levels between 174 and 655 ng/g, depending on dose. Nicotine self-administration produced similar up-regulation of nicotinic receptor binding sites in males and females, as reflected by increased right hemi-brain binding of [3H]-epibatidine, when compared to the brains of untreated control rats. These results suggest that the motivation to obtain nicotine is higher in females. Donny, E.C., Caggiula, A.R., Rowell, P.P., Gharib, M.A., Maldovan, V., Booth, S., Mielke, M.M., Hoffman, A. and McCallum, S. Nicotine Self-Administration in Rats: Estrous Cycle Effects, Sex Differences and Nicotinic Receptor Binding. Psychopharmacology (Berl) 151(4), pp. 392-405, 2000.
Sex-Related Differences in the Antinociceptive Effects of Opioids
Sex differences in morphine-induced antinociception (reduction of pain) have been described previously using thermal, chemical and electrical stimuli. The present study examined the role of nociceptive stimulus intensity and relative efficacy (magnitude of binding required for effect) of opioids on sex differences in opioid-induced antinociception. Results indicated that sex differences in potency and effectiveness increased with [1] decreases in the opioid's relative efficacy, and [2] increases in the intensity of the nociceptive stimulus. For example, high efficacy opioids were 2.5 times more potent in males than females, whereas low efficacy opioids were 8.9 times more potent in males than females. These findings suggest that the failure to find sex differences in antinociception using high efficacy opioids may not predict whether a sex difference will be found for low efficacy opioids. In fact, the use of lower efficacy opioids may provide a sensitive assay for investigating the role of sex hormones on opioid sensitivity. Cook, C.D., Barrett, A.C., Roach, E.L., Bowman, J.R. and Picker, M.J. Sex-Related Differences in the Antinociceptive Effects of Opioids: Importance of Rat Genotype, Nociceptive Stimulus Intensity, and Efficacy at the _ Opioid Receptor. Psychopharmacology, 150, pp. 430-442, 2000. Increased Sensitivity to Alprazolam in Females with a Paternal History of Alcoholism In a study of 28 women characterized as light drinkers, the anxiolytic drug alprazolam impaired performance in a dose-related manner on psychomotor, cognitive and memory tasks. At the highest alprazolam dose, women with a paternal history of alcoholism were more impaired on these measures than women without a paternal history of alcoholism. The authors also report greater alprazolam-produced increases in ratings of "difficulty concentrating" and "unmotivated behavior" as well as fewer positive subjective effects (e.g. positive mood, elation, friendliness, "drug liking") and more negative subjective effects (e.g., "bad drug effect") in women with a paternal history of alcoholism. Evans, S.M., Levin, F.R., and Fischman, M.W. Increased Sensitivity to Alprazolam in Females with a Paternal History of Alcoholism. Psychopharmacology, 150, pp. 150-162, 2000.
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Treatment Research and Development |
Differences between Methamphetamine and Cocaine Users
At the Matrix Institute on Addictions, in Los Angeles, CA, two large cohorts of cocaine and methamphetamine (MA) users sought outpatient treatment during the same four-year period. The 224 cocaine users spent more money on their drugs, more frequently had severe financial problems or bankruptcy (37.9%), and more frequently used alcohol with their drug of choice (46.9%). The 500 methamphetamine users included a higher proportion of women (40%) and Whites (80.5%), more frequently used their drug on a daily basis (43.6%), more frequently had used marijuana (56.2%) and hallucinogens (6.4%) in the past year, and more frequently had current psychiatric symptoms at admission. However, the two groups did not differ significantly in treatment retention. Retention in treatment for >90 days was most significantly correlated with reported years of heavy drug use. No significant correlation with retention was found for use of methamphetamine, gender, marital status, age, years of education, or prior drug treatment. Rawson, R., Huber, A., Brethen, P., Obert, J., Gulati, V., Shoptaw, S., and Ling, W. Methamphetamine and Cocaine Users: Differences in Characteristics and Treatment Retention. Journal of Psychoactive Drugs, 32(2), pp. 233-238, 2000.
Functional Organization of the Brain for Working Memory Differs by Gender
Gender differences in brain activation during working memory tasks were examined with fMRI. Seventeen right-handed adult subjects were studied with four different verbal working memory tasks of varying difficulty using whole brain echo-planar fMRI. Consistent with prior studies, activation of the lateral prefrontal cortices (LPFC), the parietal cortices (PC), and additionally caudate activation was observed in both sexes. The volume of activated brain tissue increased with increasing task difficulty. For all tasks, the males showed bilateral activation or right-sided dominance (LPFC, PC and caudate), whereas females showed activation predominantly in the left hemisphere. Performance data demonstrated higher accuracy and slightly slower reaction times for females. Results show highly significant gender differences in the functional organization of the brain for working memory. These variations in functional organization of the brain may be due to gender-differences in problem solving strategies or in neurodevelopment. Therefore, gender matching or stratification is necessary for studies of brain function using imaging techniques. Speck, O., Ernst, T., Braun, J., Koch, C., Miller, E., Chang, L. Gender Differences in the Functional Organization of the Brain for Working Memory. Neuroreport, 11(11), pp. 2581-2585, 2000.
Cerebral Perfusion Abnormalities in Abstinent Cocaine Abusers
Drs. Ernst, Chang and colleagues at Harbor-UCLA Medical Center used perfusion magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) to evaluate regional cerebral blood flow abnormalities in abstinent cocaine abusers. Abnormalities were evaluated and compared in 25 asymptomatic abstinent cocaine users and 15 healthy controls without a history of drug use. After co-registration of SPECT with MRI, the relative rCBF (from perfusion MRI and SPECT) and absolute rCBF (from SPECT) were determined in 10 brain regions in each hemisphere. There was a statistically significant interaction between drug use and brain region on SPECT alone (relative and absolute rCBF), and on SPECT and perfusion MRI combined, but not on perfusion MRI alone. There also was a significant interaction among gender, drug use, and brain region. Compared to the controls, abstinent cocaine abusers showed increased rCBF in the frontal white matter and in the globus pallidus, and decreased rCBF in the putamen and the temporal cortex. Female, but not male, cocaine abusers showed significantly reduced relative rCBF in the parietal gray matter and increased relative rCBF in the frontal and temporo-parietal white matter, whereas male, but not female, cocaine abusers showed significantly increased rCBF in the thalamus. SPECT and perfusion MRI detect a regional pattern of rCBF abnormalities in cocaine users that is consistent across the two methods. The hypoperfusion in the cortex and deep gray matter of the cocaine users is consistent with previous results. The increased rCBF in the white matter of cocaine users may be due to the presence of reactive glia. Ernst, T., Chang, L., Oropilla, G., Gustavson, A., Speck, O. Cerebral Perfusion Abnormalities in Abstinent Cocaine Abusers: A Perfusion MRI and SPECT Study. Psychiatry Research: Neuroimaging, l99(2), pp. 63-74, 2000.
fMRI Study Reveals An Sex Differences in Response to Visual Stimulation: Implications for Dopamine System Function
Drs. Cowan, Renshaw and colleagues at McLean Hospital investigated the visual system response to blue light as a marker of CNS dopamine tone. Given that numerous sex-related differences in CNS dopamine function have been found previously, it was predicted that blue (470 nm) and red (660 nm) light stimulation would produce sex-specific patterns of response in the primary visual cortex using the blood oxygen level dependent (BOLD) functional magnetic resonance (fMRI) method. BOLD response to red and blue light was analyzed in male and female volunteers. Results showed that near threshold, males and females showed similar BOLD signal change to red light, but males showed a threefold greater increase to blue light stimulation when compared to females. These findings support a sex- and color-dependent differential pattern of primary visual cortical response to photic stimulation and further suggest a viable method for assessing the influence of specific dopamine agonist/antagonist medications on visual function. Cowan, R.L. et al., Sex Differences in Response to Red and Blue Light in Human Primary Visual Cortex: A BOLD fMRI Study. Psychiatry Research: Neuroimaging, 100, pp. 129-138, 2000.
Heritability of Use and Abuse of Illicit Substances in Adolescents
Iacono and colleagues found in their longitudinal study on twins (Minnesota Twin Family Study, MTFS) that heritability of illicit substances was only 25% or less with heritability of tobacco use and nicotine dependence to be substantially higher: 40% and 60%, respectively. These estimates are lower than others found in adult twin studies and suggest a larger influence of environment at this younger age. Indeed, the contribution to the shared environment turned out to be a substantial 41% and 66% for illicit substance use and abuse, respectively. It was also found that, in general, these heritabilities were not different between males and females. McGue, M., Elkins, I., and Iacono, W.G.. Genetic and Environmental Influences on Adolescent Substance Use and Abuse. Am. J. Med. Genet. 96(5), pp. 671-677, 2000.
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Research on AIDS and Other Medical Consequences of Drug Abuse |
Efficacy of a Preventive Intervention for Youths Living with HIV
HIV transmission behaviors and health practices were examined among youth living with HIV (YLH) over 15 months after youth received a preventive intervention. YLH aged 13-24 years were assigned by small cohort to (1) a two-module intervention totaling 23 sessions ("Stay Healthy" and "Act Safe"), or (2) a Control condition. 73% in the Intervention Condition attended at least one session. Following the Stay Healthy module, females who attended the Intervention Condition increased their number of positive lifestyle changes and increased active coping styles more often than those in the Control Condition. Following the Act Safe Module, YLH who attended the Intervention Condition reported 82% fewer unprotected sexual acts, 45% fewer sexual partners, 50% fewer HIV-negative sexual partners, and 31% less substance use on a weighted index than those in the Control Condition. It was concluded that prevention programs can effectively reduce risk acts among YLH. Alternative formats need to be identified for delivering the intervention. Efficacy of a Preventive Intervention for Youths Living with HIV. Rotheram-Borus, M.J., Lee, M.B., Murphy, D.A., Futterman, D., Duan, N., Birnbaum, J.M., Lightfoot, M., and the Teens Linked to Care Consortium. American Public Health Association, 91(3), pp. 400-405, 2001.
Variation in Health and Risk Behavior Among Youth Living with HIV
Lifetime and current health practices and risk behaviors were examined among 350 youth living with HIV (YLH) aged 14-23 years from four AIDS epicenters (72.6% male; 26.2% African American, 36.9% Latino). YLH were relatively healthy (M CD4 cells = 499), had used substantial health care and were satisfied with the care. YLH's sexual and substance-use histories indicated substantial HIV related risk acts: the median number of lifetime partners was 25 with only 8% using condoms consistently; 14.9% had injected drugs, and 61.2% had used hard drugs. Compared with females, males had more lifetime and recent sexual partners and had used more drugs. Youth who were recently sexually active (81.3%) had multiple partners. Most of the sexually active YLH used condoms consistently (81.6%). YLH who were symptomatic or had an AIDS diagnosis were likely to have recently had more seropositive sexual partners than the asymptomatic youth. Youth disclosed their serostatus to about half of their sexual partners (53.9%). YLH with AIDS used fewer hard drugs than those without an AIDS diagnosis. Health and risk behaviors of the YLH varied significantly based on their disease stage, gender, and ethnicity, suggesting the need for tailoring interventions for subgroups of YLH. Rotheram-Borus, M.J., Lee, M., Zhou, S., O'Hara, P., Birnbaum, J.M., Swendeman, D., Wright, W., Pennbridge, J., and Wight, R.G. Variation in Health and Risk Behavior Among Youth Living with HIV. AIDS Education and Prevention, 13(1), pp. 42-54, 2001.
Drug-Using Women's Communication with Social Supporters About HIV/AIDS Issues
Communication about health issues such as HIV/AIDS is essential for people, especially women, to obtain the social support they need either to prevent illness or manage it. This article compares the kinds of HIV-related issues that HIV positive and HIV negative substance-abusing women (N=211) in New York City talk about with various types of supporters. Despite the stigma associated with AIDS and their unconventional lifestyles, both groups of women talked to a broad spectrum of supporters about a variety of HIV-related issues, though this was more the case for HIV positive women. Although the main topic that both groups discussed with their supporters was their HIV status, the women also talked about risk reduction, their supporters' HIV status, HIV testing, how to live with AIDS, information about HIV/AIDS, and the emotional impact of AIDS (e.g., fear of infection, reactions to learning test results, and the impact of knowing others who have died from the disease). Falkin, G.P., and Strauss, S.M. Journal of Drug Issues, 30(4), pp. 801-822, 2000.
Prevalence and Duration of Hepatitis C Among Injection Drug Users in San Francisco, California
Drs. Lorvick, Kral, Seal, Gee, and Edlin conducted a study to determine the prevalence of anti-HCV among IDUs in San Francisco in 1987, and to estimate how long prevalent cases have been infected. The subjects were originally recruited for an HIV prevalence study among street-recruited IDUs (the Urban Health Study). They found that injection drug users (IDUs) are the single population most affected by the hepatitis C virus (HCV). Progression to cirrhosis and/or hepatocellular carcinoma occurs in 20-30% of chronically HCV infected persons 20-30 years after infection. Stored serum samples collected from 372 IDUs in 1987 were tested for HCV antibody. They found that 353/372 (95%) samples were positive for HCV antibody. Prevalence was strongly associated with the duration of injection drug use. Of those injecting≤ 2 years, 75.9% were infected (95% CI .56, .90). Of those injecting >10 years, 98.8% were infected (95% CI .96, .99). There were no significant differences in prevalence by race, gender or frequency of injection. The median year of commencing injection drug use was 1972 (interquartile range 1967, 1979). Because most HCV infections occur within two years of initiating injection drug use, the majority were likely infected by the mid-1970's. The vast majority of IDUs in this sample were infected with HCV in 1987. Many are entering their third decade of infection and may be progressing to liver disease at this time. Lorvick, J., Kral, A.H., Seal, K., Gee, L., and Edlin, B.R. Prevalence and Duration of Hepatitis C among Injection Drug Users in San Francisco, California. American Journal of Public Health, 91, pp. 46-47, 2000.
Drug Abuse Among Athletes
Pope and his colleagues from McLean Hospital/Harvard School of Medicine have observed a substantial drug abuse problem among athletes in the U.S. In a survey of 511 clients entering five gymnasiums (Kanayama et al. 2000), they found that among men, 18% report use of androstenedione and/or other adrenal hormones, 25% report ephedrine use, and 5% report anabolic steroid use within the past three years; while among women, these rates were 3%, 13%, and 0%, respectively. Extrapolating from these figures to the U.S. as a whole, the authors estimate that possibly 1.5 million American gymnasium clients have used adrenal hormones and 2.8 million have used ephedrine within the last three years. They further report that nalbuphine may represent a new drug of abuse among athletes, especially those using anabolic steroids. (Nalbuphine, a nonscheduled opioid agonist/antagonist analgesic, is used for the treatment of pain.). Authors (Wines et al., 1999) conducted interviews on 11 subjects who reported nalbuphine use. Eight subjects were clinically dependent on nalbuphine, and seven of these experienced tolerance and withdrawal symptoms. Further, eight subjects who had never injected drugs intravenously before, reported using nalbuphine by this route. Nalbuphine-related morbidity was extensive and included medical complications and psychiatric symptoms (comorbid Axis I disorders). These observations suggest that nalbuphine may represent a new drug of abuse among anabolic steroids abusing athletes. Finally, the investigators (Halpern and Pope, 2001) also report that there is a widespread use of the Internet among well-educated adults and teenagers for obtaining medical information about allucinogens and how to obtain and use these drugs. Kanayama, G., Gruber, A.J., Pope, H.G., Borowiecki, J.J., and Hudson J.I. Over-the-Counter Drug Use in Gymnasiums: An Underrecognized Abuse Problem? Psychotherapy and Psychosomatics, May/June issue, 2001; Wines, J.D., Gruber, A.J., Pope, H.G., and Lukas, S. Nalbuphine Hydrochloride Dependence in Anabolic Steroid Abusers. Am. J. Addictions, 8, pp. 161-164, 1999; Halpern, J.H. and Pope, H.G. Hallucinogens on the Internet: A Vast New Source of "Underground" Drug Information. American Journal of Psychiatry, 158, pp. 481-483, 2001.
Identifying Prenatal Exposure to Illicit Drugs Using Meconium Testing and Maternal Self-Report
In the four-site Maternal Lifestyle Study (Detroit, Miami, Memphis, Providence) of in utero cocaine and/or opiate exposure, meconium specimens of 8,527 newborns were analyzed by immunoassay (EMIT) with GC/MS (gas chromatography/mass pectrometry) confirmation. Maternal self-report of drug use during pregnancy was determined during a hospital interview. Recruitment occurred between May 1993 and May 1995. Prevalence and observed metabolites showed considerable variation across the four sites, and exposure status was higher in low birth weight infants. Results indicated that accurate identification of exposure is likely to be improved with GC/MS confirmation and when the meconium testing is used in conjunction with a maternal hospital interview (e.g., 254 mothers denied use but their infants had positive meconium confirmation for cocaine/opiates, thus allowing identification of an additional 38% of the cocaine/opiate exposed infants by means of meconium testing). Importantly, had the study relied on maternal report only, these 254 infants would have been eligible for inclusion in the unexposed group. However, at the current stage of this new and useful technology, many questions still remain about the disposition of drugs in meconium, and the investigators caution against the use of quantitative analysis of drugs in meconium to estimate the degree of exposure. Lester, B.M., ElSohly, M., Wright, L.L., Smeriglio, V.L., Verter, J., Bauer, C.R., Shankaran, S., Bada, H.S., Walls, H.C., Huestis, M.A., Finnegan, L.P., and Maza, P.L. Pediatrics, 107, pp. 309-317, 2001.
Initial Plasma HIV-1 RNA and Progression to AIDS in Men and Women
Differences in plasma HIV-1 RNA levels (viral load) have been observed in some studies comparing HIV-infected men and women, but conclusive results have been limited by study design or small sample sizes. In this new larger analysis in a prospective cohort study of 202 IDUs who underwent seroconversion, viral load was measured and the association of initial viral load with disease progression was assessed. Of these seroconverters, 156 (77%) were men and 46 (23%) were women. The median viral load after seroconversion was significantly lower in women vs. men (15,103 vs. 50,766 copies per millimeter; P<.001), but CD4+ lymphocyte counts (CD4) did not differ according to sex. The median initial viral load remained approximately 0.5 log lower in women vs. men after adjusting for age, time from estimated seroconversion to first viral load test (P=.001), and CD4 at seroconversion (P=.001). The difference in viral load between men and women persisted for several years after seroconversion. HIV infection progressed to AIDS in 29 men and 15 women; time to AIDS did not significantly differ in men vs. women (P=.18). While viral load had a similar qualitative predictive value for progression to AIDS in men vs. women, the same absolute viral load conferred different risks of AIDS in men vs. women, e.g., an initial viral load of 17,149 copies per milliliter was associated with progression to AIDS in women but not in men, while the median viral load among men who did not progress to AIDS was 40,634 copies. Given that viral load has been the basis for the current guidelines regarding initiation of antiretroviral therapy in HIV-infected patients, these findings have implications that require further study. Analyses to determine if there is a threshold viral load value that predicts progression, and research on the underlying biologic mechanism of the observed viral load differences are needed. Sterling, T.R., Vlahov, D., Astemborski, J., Hoover, D.R., Margolick, J.B., and Quinn, T.C. New England Journal of Medicine, 344, pp. 720-725, 2001.
Study Examines the Social Network Context of HIV Risk Behavior Among IDUs
Researchers characterized social network context of HIV risk behaviors among injection drug users who participated in the Baltimore Needle Exchange Program (NEP) from 1995-1997. They conducted interviews with 1,184 IDUs in which they asked each respondent to give the initials of up to five of their closest friends and whether, with each friend, they had injected drugs, shared syringes, had sex, or drank alcohol. Of the 203 (17.1%) IDUs who reported using a syringe after someone else, 78.3% reported sharing with close friends, and the adjusted odds ratio of any sharing and sharing with close friends was 30.9. IDUs were more likely to report sharing with strong-tie close friends and less likely to report sharing with other close friends if those friends were weak ties and new to their network. Friendship ties were not stable, with fewer than 30% of the friends being repeat nominations. The findings from this study show that many IDUs engage in selective risk taking that may minimize their disease risk exposure in the short term. In other words, risk taking is not random but rather, is more likely to occur with strong-tie close friends than with weak-tie ones. However, the turnover in relationships among IDUs represents a risk potential for infection transmission that could be ongoing within this population. As a result, as part of a comprehensive HIV prevention program, NEPs need to do more than provide access to sterile syringes and drug treatment referral. Valente, T.W. and Vlahov, D. Selective Risk Taking Among Needle Exchange articipants: Implications for Supplemental Interventions. Am J Public Health, 91, pp. 406-411, 2001.
Study Examines Sex-Specific Behaviors and HIV Among IDUs in Montreal
The objective of this study was to examine sex-specific behaviors associated with HIV infection among injection drug users in Montreal. Researchers recruited a total of 2,741 active drug users (2,209 [80.6%] men) between 1988 and 1998 for interviews regarding sociodemographic characteristics, drug use history and current drug use, drug-related behavior, sexual behavior, and other information. Participants were also tested for HIV antibodies. Sex-specific independent predictors of HIV prevalence were assessed by stepwise logistic regression. The overall prevalence of HIV among study participants was 11.1%; the prevalence was 12.0% among men and 7.5% among women. In multivariate models, a history of sharing syringes with a known seropositive partner (odds ratio [OR] for men 2.44, 95% confidence interval [CI] 1.72-3.46; OR for women 3.03, 95% CI 1.29-7.13) and of sharing syringes in the past 6 months (OR for men 0.61, 95% CI 0.44-0.85; OR for women 0.32, 95% CI 0.14-0.73) were independently associated with HIV infection. Other variables associated with HIV infection were homosexual or bisexual orientation, cocaine rather than heroin as drug of choice, frequency of injection drug use, and obtaining needles at a pharmacy or through needle exchange programs (for men only) and obtaining needles at shooting galleries and being out of treatment (for women only). Findings support the hypothesis that risk factors and processes related not only to sexual behaviors, but also to the social contexts of drug use and service utilization, might differ with regard to HIV prevalence between men and women. These sex-related differences should be taken into account in the development of preventive and clinical interventions. Bruneau, J., Lamothe, F., Soto, J., Lachance, N., et al. Sex-Specific Determinants of HIV Infection Among Injection Drug Users in Montreal. Canadian Medical Assoc Journal, 164(6), pp. 767-73, 2001.
An Event Analysis of Drug-Using Women's Sexual Risk
Researchers used event analysis to describe the most recent sexual events of drug-using women and their male partners, and to identify relationship-specific and event-specific determinants of condom use. Women drug users (n=320) were recruited from the streets of East Harlem. After validation of drug use, they participated in structured interviews and were offered HIV testing and counseling. Data were collected on demographic characteristics, relationship factors (including age of partner, race/ethnicity concordance, and HIV serostatus of partners), and event-specific factors, including sexual repertoire, communication about condom use, and perception of HIV risk. Univariate and multivariate analyses identified 5 major variables associated with event-specific condom use: Closeness to partner, perceived dyadic serostatus, sexual repertoire, communication about condoms, and perceived control of condom use. Behavioral interventions to reduce sexual risk should focus on dyads with long-standing sexual relationships and on the dynamics of the relationship, especially the issues of dyadic serostatus, intimacy, communication, and control. Tortu, S., McMahon, J., Hamid, R., and Neaigus, A. Drug-Using Women's Sexual Risk: An Event Analysis. AIDS and Behavior, 4(4), pp. 329-340, 2000.
Women IDUs Who Have Sex With Women Exhibit Increased HIV-Related Risk Behaviors
Researchers reviewed the published literature on HIV seroprevalence and HIV-related risk behaviors among women IDUs who have sex with women. They report that, since the late 1980s, published studies have converged into a consistent pattern concerning this population. Specifically, compared to other IDUs, women IDUs who have sex with women report higher levels of HIV-related risk behaviors (risky injection practices, unprotected sex), and in many cases exhibit higher levels of HIV seroconversion or seroprevalence. For example, a large study of 9,621 out-of-treatment IDU women found that women IDUs who had sex with both men and women during the prior six months were more likely than the other women to inject cocaine at least daily and score higher on a summary index on needle risk. Data from these and additional studies suggest that a relatively large proportion of women IDUs are women who have sex with women. Information regarding women injectors who have sex with women are widely collected but infrequently reported, indicating the need to apply promising research and analysis strategies to explore the meaning behind this pattern of increased vulnerability to HIV. Young, R.M., Friedman, S.R., Case, P., Asencio, M.W., and Clatts, M. Women Injection Drug Users Who Have Sex With Women Exhibit Increased HIV Infection and Risk Behaviors. J Drug Issues, 30(3), pp. 499-524, 2000.
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Epidemiology, Etiology and Prevention Research |
Family Risk and Resiliency Factors, Substance Use, and the Drug Resistance Process in Adolescence
Recent approaches to drug prevention have emphasized risk and resiliency factors. Two models have been developed to explain these factors, one which posits that separate elements make up each set and the other which posits that a single factor can be either a risk or a resiliency factor depending on, for example, if it is present (resiliency) or absent (risk). This study tested these models and attempted to compare the effects of risk and resiliency across gender and ethnicity. Results support the model in which risk and resiliency are discrete sets of factors and demonstrate that overall resiliency factors play a larger role than risk factors in substance use and drug resistance processes. However, gender proved to be an important moderator of these effects. For adolescent males, resiliency has an indirect effect on overall substance use through age of first use, while risk has a direct effect on overall substance use. For adolescent females, resiliency has a direct effect on overall substance use and risk has an indirect effect through age of first use. This indicates that while early interventions are important for both genders, esiliency factors must be dealt with before initiation of substance use for males. Findings did not differ substantially across ethnicity, although the small African-American sample size may have limited power to detect differences. Moon, D.G., Jackson, K.M. and Hecht, M.L. Family Risk and Resiliency Factors, Substance Use, and the Drug Resistance Process in Adolescence. Journal of Drug Education, 30(4), pp. 373-398, 2000.
Male Adolescent Friendships and Aggression Toward Female Partners
Deviancy training was examined as a risk factor for physical and psychological aggression toward a female partner among boys and young men in the Oregon Youth Study. Hostile talk about women during videotaped male friendship interactions was hypothesized to indicate a process by which aggression toward women is reinforced within male peer networks with both antisocial behavior and hostile talk being predicted to be associated with later aggression toward a female partner. Prospective developmental models were tested from 9-20 years of age through young adulthood. Findings indicated that the relation of deviant peer association in adolescence and later aggression toward a partner was mediated by antisocial behavior; observed hostile talk about women with male peers explained additional variance in aggression toward a partner. Aggression Toward Female Partners by At-Risk Young Men: The Contribution of Male Adolescent Friendships. Capaldi, D.M., Dishion, T.J., Stoolmiller, M., and Yoerger, K. Dev. Psych., 37(1), pp. 61-73, 2000.
Deviant Friendships and Problem Behavior
This study examines adult reports of externalizing and internalizing psychopathology at home and school in a sample of 224 high-risk adolescent boys and girls (mean age 12 yrs). Four groups of young adolescents were defined, based on the consistency of teacher and parent Child Behavior Checklist reports: normal, internalizing, externalizing only, and co-morbid. Group comparisons revealed the co-morbid and externalizing groups were more engaged in a deviant peer group and were observed in higher levels of deviancy training with their friends, compared to other young adolescent groups. In general, elevated levels of arrest, drug use, and sexual promiscuity were associated with cross-setting consistency in externalizing disorders. Co-morbid youth, however, showed the highest levels of sexual promiscuity in middle adolescence, compared to all other groups. These findings are consistent with a developmental account of adolescent maladjustment and suggest that emotional disturbance in early adolescence might exacerbate youth vulnerability, especially to deviancy training within friendships. Dishion, T.J. Cross-Setting Consistency in Early Adolescent Psychopathology: Deviant Friendships and Problem Behavior Sequelae. J. Personality, 68 (6), pp. 1109-1126, 2000.
Drug Use By Adolescent Mexican Americans and Adolescents in Mexico
Investigators at UCLA compared high school students in Baja California Norte (BCN), Mexico (n = 775), with Mexican American students in Los Angeles (LA), California (n = 516). The students' use of cigarettes, alcohol, marijuana, cocaine, inhalants, and other illicit drugs were compared, because these vary by gender, country, and their age of first drug use and are influenced by demographic variables, individual characteristics, and environmental influences. More BCN students than LA students had used alcohol, but more LA than BCN students had used illicit drugs and initiated drug use earlier. When demographic variables were influential, they were most powerful and increased the risk for drug use more than environmental factors or individual characteristics. Environmental factors were most influential for boys' drug use, whereas environmental and demographic variables were most influential for girls' drug use. Felix-Ortiz, M., Villatoro-Velazquez, J.A., Medina-Mora, M.E., and Newcomb, M.D. Adolescent Drug Use in Mexico and Among Mexican American Adolescents in the United States: Environmental Influences and Individual Characteristics. Cultural Diversity and Ethnic Minority Psychology, 7(1), pp. 27-46, 2001.
Antisociality, Substance Dependence, and the DRD5 Gene
Researchers at the University of Pittsburgh reported a pilot population-based study of a microsatellite polymorphism at the DRD5 locus in adult European-Americans that showed its association with childhood symptom counts for oppositional defiant disorder (ODD) in males and females and adult antisocial personality disorder (ASPD) in females. No association with childhood conduct disorder symptom count was observed. ODD mediated the genotype-ASPD relationship in females. Neither ODD nor ASPD significantly mediated the relationship between the genotype and the liability to substance dependence (SD). The data suggest involvement of the DRD5 locus in the variation and sexual dimorphism of SD liability and antisociality and in the evelopmental continuity of antisociality. Vanyukov, M.M., Moss, H.B., Kaplan, B.B., Kirillova, G.P., and Tarter, R.E. Antisociality, Substance Dependence, and the DRD5 Gene: A Preliminary Study. American Journal of Medical Genetics, 96(5), pp. 654-658, 2000.
Stalking as a Variant of Intimate Violence: Implications From a Young Adult Sample
There is a limited but growing literature which suggests that stalking is a variant of intimate violence. The purpose of this study was to examine physical, psychological, and stalking victimization and perpetration among males and females. Alcohol use was also examined. The sample was 46 male and 84 female undergraduate students who reported stalking victimization and perpetration after a difficult breakup, and psychological and physical victimization and perpetration during that specific relationship. Overall, 27% of the sample study was classified into the stalking victimization group, which is consistent with other stalking prevalence rates among college samples. For females, stalking victimization was significantly associated with physical and psychological abuse victimization. For males, stalking victimization was significantly associated with psychological abuse victimization. However, there was also a strong significant reciprocal relationship of stalking and psychological abuse victimization and erpetration, especially for males. Also, alcohol use was significantly associated with victimization and perpetration of stalking and psychological abuse for males. The data from this study contribute to the hypothesis that stalking is a variant of or extension of intimate violence, especially for females. Implications and recommendations for future research are discussed. Stalking as a Variant of Intimate Violence: Implications from a Young Adult Sample, Violence Vict, 15(1), pp. 91-111, 2000.
The Suspected Association Between Methamphetamine ('ice') Smoking and Frequent Episodes of Alcohol Intoxication: Data from the 1993 National Household Survey on Drug Abuse
Drs. Furr, Delva and Anthony at Johns Hopkins University estimated the strength of association between frequent episodes of alcohol intoxication and recent smoking of methamphetamine ('ice'). Using the 1993 National Household Survey on Drug Abuse, a total of 101 ice smokers were matched on neighborhood of residence to 816 non-smokers. Based upon conditional logistic regression analyses, persons with daily episodes of alcohol intoxication were estimated to have been five times more likely to smoke ice, as compared with non-drinkers or drinkers with little or no history of alcohol intoxication. This estimate includes statistical adjustment for potential confounders (e.g. age, sex) and was statistically significant (P=0.01). The association between frequent alcohol intoxication and 'ice smoking' offers an intriguing lead for a broad range of new research. Furr, C.D., Delva J., and Anthony J.C. The Suspected Association Between Methamphetamine ('ice') Smoking and Frequent Episodes of Alcohol Intoxication: Data from the 1993 National Household Survey on Drug Abuse. Drug Alcohol Depend., 59(1)10, pp. 89-93, 2000.
Differential Recall of Intimate Partner Violence
Research on intimate partner violence (IPV) has found that partners often do not agree about the occurrence of IPV, with abusive male partners reporting lower levels than their abused female partners. Among the reasons suggested for these differences are: denial or self-deception, fear of legal sanctions, and gender differences in recall of interpersonal events. This qualitative study focused on the factors that account for gender differences in recall of male-to-female partner conflict. Interviews were conducted with battered women recruited from a shelter, male batterers in an intervention program, and equal numbers of men and women recruited from the community who had no history of IPV in their relationships. Subjects were asked an open-ended questionnaire and then asked questions based on their response. The main results of this study indicate that participants believe that women remember more than men, both choose what they want to remember, and both remember that they were right in the conflict. Participants suggested that women tend to focus on the emotional aspects of a fight and remember fights longer. 19% of respondents suggested that substance abuse might contribute to distorted recollections of partner violence. The female victims group, in particular, mentioned the intentional forgetting of fights. The overall significance of this study is that it suggests mechanisms underlying partner disagreement about IPV that have not previously been considered. Armstrong, T.G., Heiderman, G., Corcoran, K.J., Fisher, B., Medina, K.L. and Schafer, J. Disagreement About the Occurrence of Male-to-Female Intimate Partner Violence: A Qualitative Study. J. Fam. Comm. Health, 24(1), pp. 55-75, April 2001.
Partner Violence Among Mexican American Women
The prevalence of intimate partner violence (IPV) and associated risk and protective factors among Mexican-American women was studied using data from a cross-sectional household survey of U.S. residents of Mexican origin. The analysis includes data from women who were involved in an intimate relationship with a male partner and who answered questions about violence (n=1155). Approximately two fifths of the women were U.S. born. The self-reported prevalence of physical abuse by a current partner was 10.7%. Multivariate analysis showed that U.S birthplace, young age, urban residence, and having 4 or more children were associated with physical abuse. Social support and regular church attendance were protective. A consistent association was found between IPV and higher acculturation, e.g., years in U.S., country of schooling, dominant language. It is suggested that aspects of traditional Mexican culture may serve a protective function for families. Lown, E.A. and Vega, W.A. Prevalence and Predictors of Physical Partner Abuse among Mexican-American Women, A. J. Pub. Health, 91, pp. 441-445, 2001.
Community Level Effects on Prevalence of Substance Use During Pregnancy
Multilevel logistic regression models were used to analyze individual and community correlates of prenatal substance use. This study analyzed a subset of data from the California Perinatal Substance Exposure Study (PSE), the subjects in this study (n=10,611) are the subset of women identified as white, non-Hispanic (n=10,611) and Black/African-American (n=2,669) from the larger multiethnic sample (n=29,494); Latinas were not included in this study. Using census data, the proportion of zip code residences receiving public assistance was attached to each respondent's data in the PSE data file. Analyses showed that, except for alcohol, levels of neighborhood public assistance had an independent, significant effect on prevalence of substance use; increasing levels of neighborhood poverty increased the likelihood of a pregnant woman testing positive. Black women had higher predicted prevalence rates for alcohol and cocaine, while White women had higher predicted risks for tobacco, marijuana, and amphetamines. After controlling for neighborhood public assistance levels, no racial differences were seen in the category overall illicit drug use or opiate use. Future more detailed studies are needed to determine if neighborhood poverty effects on substance use are due to compositional effects, e.g., greater access to drugs, greater overall deviance, etc. or contextual factors, e.g., increased stresses associated with poor housing, lack of social services, etc. Finch, B.K., Vega, W.A., and Koldny, B. Substance Use During Pregnancy in the State of California, USA, Soc. Sci. Med. 52, pp. 571-583, 2001.
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Adolescent Substance Abuse Treatment Outcome: The Role of Substance Abuse Problem Severity, Psychosocial, and Treatment Factors
A structural equation model incorporating substance abuse problem severity, psychosocial risk and protection, and treatment variables was used to examine adolescent drug abuse treatment outcome pathways across 6- and 12-month follow-up points. Findings on resiliency factors and an empirical method adapted from previous research were used to select and assign 10 psychosocial factors to either a multiple protective factor index or a risk factor index. Gender, substance abuse problem severity, treatment modality, treatment length, and aftercare participation were also examined as outcome predictors. The findings suggest that treatment intensity decisions may be better informed by pretreatment psychosocial risk level rather than by substance abuse problem severity. The present study also suggests that drug-abusing adolescents who receive sufficiently long treatment, participate in aftercare, and possess at least 1 individual or interpersonal protective factor during their recovery process have the best chance to maintain gains made during treatment. Latimer, W.W., Newcomb, M., Winters, K.C., and Stinchfield, R.D. Journal of Consulting and Clinical Psychology, 68(4), pp. 684-696, August 2000.
Social Relationships of Crime-Involved Women Cocaine Users
Social relationships play a significant role in drug use and recovery, perhaps especially for women. Research on social relationships among crime-involved women drug users is reviewed, including both well established findings and more recent topics of inquiry. Several open questions about social relationships of women drug users are then examined in data from a study conducted in the Miami (Florida) metropolitan area in 1994-1996. For a study of barriers to drug treatment for crime-involved women cocaine users, over 400 women were interviewed in treatment programs and an equal number were recruited on the street. Respondents were asked about their social relationships during the last 30 days on the street in regard to both legal and illegal activities. This included crime partnerships, help obtaining cocaine, living arrangements, help with living expenses, children and help with child care, help with several ordinary problems, and pressures to enter treatment. The analysis looks at how much social support crime-involved women cocaine users have in their ordinary daily activities and who provides this support. Pottieger, A.E., and Tressell, P.A. Journal of Psychoactive Drugs, 32(4), pp. 445-460, October-December 2000.
The Impact of Women's Family Status on Completion of Substance Abuse Treatment
This study examines the role of family status and demographic characteristics in explaining the nearly 60% dropout rate for women in substance abuse treatment. Data from the administrative record files of the Illinois Office of Alcoholism and Substance Abuse (OASA) for the fiscal year 1996-1997 were analyzed for women age 12 or older who completed intake for publicly funded substance abuse treatment and whose outpatient treatment records were closed at year-end. Multivariate logistic regression models found that the likelihood of not completing treatment was greatest for women who were African American, pregnant, had custody of minor children, or were younger than age 21. However, African American women who had children in foster care were more likely to complete treatment. Implications for treatment and research are discussed. Scott-Lennox, J., Rose, R., Bohlig, A., and Lennox, R. J Behav Health Serv Res, 27(4), pp. 366-379, November 2000.
The Relationship Between the Quality of Drug User Treatment and Program Completion: Understanding the Perceptions of Women in a Prison-based Program
To determine why some women offenders complete prison-based drug user treatment and others leave early, clients' (N = 101) perceptions of various aspects of the quality of the treatment experience were compared. Analyses of both quantitative and qualitative data indicate that clients who completed the program had a more favorable perception of staff and felt empowered by the experience in treatment. Most of the clients who left early did so because of conflicts or disagreements with the program's rules. We discuss how a supportive approach to personal development may enhance client perceptions of program quality and increase retention rates. Strauss, S.M., and Falkin, G.P. Substance Use & Misuse, 35(12-14), pp. 2127-2159, October-December 2000.
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