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National Institute on Drug Abuse
Women and Sex/Gender Differences Research
Director's Report to Council
Research Findings Excerpts
February, 1999
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Basic Research |
Chronic Running Activity Decreases Sensitivity to Morphine-Induced Analgesia
The effects of exercise on morphine-induced analgesia were examined in male and female rats. Male rats housed in activity wheels (active group) for 20 days were more sensitive to pain than rats housed in standard laboratory cages (inactive group). Additionally, both active male and female rats displayed decreased morphine-induced analgesia relative to inactive controls. Moreover, females that had been inactive and then were permitted to run showed less morphine-induced analgesia relative to inactive rats, and to their own nociceptive responses when sedentary. In contrast, morphine-induced analgesia in initially active females who were housed in standard cages for 17 days prior to a second nociceptive test was enhanced relative to their first nociceptive test and to presently active rats. These observations showed that the attenuation of morphine analgesia induced by running is reversible and not permanent. Short term exposure to exercise (24 h running) had no significant effect on morphine-induced analgesia. These results indicate that chronic activity can decrease morphine's analgesic properties. These effects may be due to cross tolerance between endogenous opioid peptides released during exercise and exogenous opioids. Kararek, R.B., Gerstein, A.V., Wildman, R.P., Mathes, W.F., D'Anci, K.E. Pharm. Biochem. and Behav., 61(1), pp. 19-27, 1998.
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Behavioral Research |
Acute Effects of Alprazolam in Women with Premenstrual Dysphoric Disorder (PMS)
Research by Dr. Suzette Evans and colleagues at New York State Psychiatric Institute suggests that acute administration of alprazolam is not a useful treatment for PMS. Double-blind testing of mood and performance changes under varying doses of alprazolam and placebo during the luteal and follicular phases of subjects with confirmed PMS indicated substantial changes in mood as a function of the cycle phase. Alprazolam, however, failed to improve negative mood, but instead increased negative mood in the follicular phase and it impaired task performance in both phases. Subjective measures indicative of abuse liability did not increase following alprazolam administration. Alprazolam's failure to improve negative mood premenstrually, its increase in negative mood in the follicular phase, and its impairment of task performance in both phases argue against its clinical usefulness when administered acutely. Evans, S.M, Haney, M., Levin, F.R., Foltin, R.W., Fischman, M.W. Neuropsycho-pharmacology, 19, pp. 499-516, 1998.
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AIDS Research |
Increased Transmission of Vertical Hepatitis C Virus (HCV) Infection to Human Immunodeficiency Virus (HIV) Infected Infants of HIV and HCV Co-infected Women
The transmission of perinatal HCV infection was studied retrospectively in infants born to HCV and HIV co-infected women enrolled in a prospective natural history study of HIV transmission. Infant HCV infection was assessed by RNA PCR. The overall rate of vertical HCV transmission was 16.4% (9/62). The rate of HCV infection was higher among HIV-infected infants than among HIV-uninfected infants (40% vs.5%; OR, 8.2; p=.009). This difference in transmission was not related to maternal HCV viral load by branched DNA assay, or mode of delivery. The rate of HCV transmission in HIV-uninfected infants of HIV and HCV co-infected mothers was similar to that reported for infants born to HIV-uninfected mothers. Papaevangelou, V., Pollack, H., Rochford, G., Kokka, R., Hou, Z., Chernoff, D., Hanna, Krazinski, K., Borkowsky, W. J. Infect Dis., 178, pp.1047-52, 1998.
Sex Differences in HIV-1 Viral Load and Progression to AIDS
A study of HIV-1 viral load differences in men and women was performed in an ongoing cohort study of injection drug users. Women were found to have significantly lower viral load measurements than men. HIV-1 was measured by branched chain DNA at baseline, and by reverse-transcriptase PCR and quantitative microculture on follow-up three years later. Median viral load measurements were significantly lower in women than men by all three methods. Viral load measurements in women were 38- 65% of those in men. The association of lower viral load in women remained even after adjusting for CD4 cell count, race, and drug use. While men and women had statistically similar time to AIDS, women with the same viral load as men had a 1.6-fold higher risk of AIDS, or, equivalently, women with half the viral load of men had a similar time to AIDS. These results suggest that, while men and women have similar time to AIDS, there is a different relationship between viral load and AIDS in women compared to men. While a biological mechanism remains to be elucidated, these findings have implications for timing of initiation of therapy relative to viral load thresholds in women. Farzadegan, H., Hoover, D., Astemborski, J., Lyles, C.M., Margolick, J.B., Markham, R.B., Quinn, T.C. Lancet, 352, pp.1510-1514, 1998.
Perinatal Transmission of Hepatitis C Virus from HIV-1 Infected Mothers
Antepartum plasma hepatitis C virus (HCV) RNA was quantified in 155 mothers enrolled in the Women & Infants Transmission Study (WITS) who were co-infected with HCV and HIV, and HCV RNA was serially assessed in their infants. Of 155 infants born to HCV-antibody positive mothers, 13 (8.4%) were HCV infected. The risk of HCV infection was 3.2-fold greater in HIV-infected infants compared with HIV-uninfected infants (17% vs. 5.4%, p=0.04). The median concentration of plasma HCV RNA was higher among the 13 mothers with HCV-infected infants (2.0 x 10(6) copies/mL) vs. 142 mothers with HCV-negative infants (3.5x 10(5) copies/mL; p<0.001). There were no instances of HCV transmission from 40 mothers with HCV RNA concentrations of <10(5) copies/mL. The results indicated that HIV-infected infants have a higher risk of HCV infection than HIV-uninfected infants, but that women dually infected with HIV-1 and HCV with little or no detectable HCV RNA have a low risk of transmitting HCV to their infants. Thomas, D.L., Villano, S.A., Riester, K.A., Hershow, R., Mofenson, L., Landesman, S.H., Hollinger, F.B., Davenny, K., Riley, L., Diaz, C., Tang, H.B., and Quinn, T. J. Infect Dis.,177, pp. 1480-1488, 1998.
Stages of Adaptation and Negotiating Behavioral Change in HIV+ Adolescent Girls
A demonstrative case of an HIV-positive girl is presented in order to illustrate the stages of adaptation that HIV positive youth undergo (i.e., acceptance, resumption of life, coping with reminders of serostatus). Also discussed is the process by which this individual changes her behavior (e.g., reduction in transmission behaviors, adherence to medical programs, improving quality of life) and the integral role and contributions the service provider can make in the behavioral-change process for HIV-positive youth. Finally, this case illustrates some of the unique issues encountered by HIV-positive women and how those issues can be incorporated into a comprehensive, coordinated, and continuous system of care through an intervention such as Teen Linked through Care (TLC). Lightfoot, M. and Rotheram-Borus, M.J. Negotiating Behavior Change with HIV-Positive Adolescent Girls. AIDS Patient Care, 12(5), pp. 395-401, 1998.
Prevention of Substance and Sexual Risk-Taking in Hispanic Women
The concepts of risk and resilience, which are at the heart of health promotion and risk prevention are discussed, and used to demonstrate the acceptability of these concepts in the development and pilot testing of a primary prevention intervention to reduce substance abuse and risky sexual behaviors among low-income, predominantly Mexican-American women. Six important findings emerged from this pilot study: 1) Motivation and readiness are key to recruitment and consistent participation; 2) The quality of the content and materials and the use of participatory learning principles and teaching methods are key to effective teaching and learning; 3) The importance of a trusting and caring environment is essential; 4) The intervention must be tailored to life's realities and must address felt needs; 5) Risky behavioral decisions are often not taken rationally or consciously; 6) Cultural and family norms play a significant role in decision-making. Lindenberg, C.S., et al. Resilience and Risk: Preventing Substance Abuse and Sexual Risky Behaviors Among Low-Income Minority Young Women. Maternal Child Nursing, 23(2), pp. 99-104, 1998.
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Clinical and Services Research |
Group Cognitive-Behavior Therapy For Dual-Diagnosis Women
Dr. Lisa Najavits developed a manualized treatment specifically adapted to the clinical needs of women with comorbid post-traumatic stress disorder (PTSD) and substance use disorder. No effective treatment has been identified for this substantial subpopulation of female drug abusers who also experience PTSD (33-59%). Outcome results on 17 women who completed the protocol treatment showed significant improvements in substance use, trauma-related symptoms, suicide risk, suicidal thoughts, social adjustment, family functioning, problem solving, depression, cognitions about substance use, and didactic knowledge related to the treatment. Results were based on assessments at pre-treatment, during treatment, post-treatment, and 3-month follow-up. The data suggest that women substance abusers with PTSD are highly responsive and able to show marked improvements when provided with a treatment that is adapted to their needs. Najavits, L.M., Weiss, R.D., Shaw, S.R., and Muenz, L.R. "Seeking Safety": Outcome of a New Cognitive-Behavioral Psychotherapy for Women with Posttraumatic Stress Disorder and Substance Dependence. Journal of Traumatic Stress, 11, pp. 437-56, 1998.
Current Approaches to Drug Treatment for Women Offenders
Treatment approaches at eight corrections- and community-based programs in New York City and Portland, Oregon are reviewed. Data were obtained from life history interviews conducted with 60 women and from observation of treatment. Drug abuse treatment programs for women offenders employ a range of therapeutic interventions to address drug use and criminality. Recently, programs have begun to address victimization experiences as an integral if not central feature of women's drug use and participation in illegal activities. Programs have tailored treatment approaches for women offenders by offering incest and domestic violence survivor groups, assigning therapeutic rather than punitive sanctions, and training corrections staff to support treatment goals. Welle, D., Falkin, G.P., Jainchill, N. Journal of Substance Abuse Treatment, 15(2), pp. 151-163, 1998.
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Epidemiology, Etiology and Prevention Research |
Genetic and Environmental Risk Factors in Cannabis Use, Abuse, and Dependence: A Study of Female Twins
This study examined the role of genetic and environmental risk factors in the development of cannabis use, abuse and dependence. Analyses of interviews with 485 monozygotic and 335 dizygotic female twin pairs demonstrated that both genetic and familial-environmental factors explained liability to cannabis use, while heavy use, abuse, and dependence symptoms were solely related to genetic factors, with heritabilities ranging from 62%-79%. Thus, while family and social factors play a key role influencing the risk to initiate cannabis use, heredity appears to determine the progression to abuse and dependence. These findings in women are consistent with other studies of genetic factors in drug abuse liability in men. Kendler, K.S., Prescott, C.A. Amer. J. of Psychiatry, 155(8), pp. 1016-1022, 1998.
Genetic and Environmental Risk Factors in Cocaine Use, Abuse, and Dependence: A Study of Female Twins
A study of cocaine use in monozygotic and dizygotic female twin pairs found that both genetic and environmental factors accounted for twin resemblance in liability to cocaine use, while resemblance for cocaine abuse and dependence symptoms was due solely to genetic factors. Heritability for cocaine abuse was estimated at 0.79. These findings are consistent with those of other studies of male veterans, adoptees, animals, and other drugs, and highlight substantial individual variation in liability to cocaine abuse and dependence. Family and social factors, toward which interventions might be targeted, are most salient to issues of drug initiation. Kendler, K.S. and Prescott, C.A. British Journal of Psychiatry, 173, pp. 345-350, 1998.
Competence and Drug Use
One construct of the Social Stress Model of Drug Abuse is "competence". This article reviews the empirical evidence for the association of competence with drug use, and describes the preliminary development of a multi-scale instrument designed to assess drug protective competence in low-income Hispanic childbearing women. Hypothesis testing was used to assess construct validity. Four drug protective competence domains (social influence, sociability, self-worth and control/responsibility) were found to be statistically associated with drug use behaviors. The other four domains (intimacy, nurturance, goal directedness and spiritual directedness) while not statistically significant, showed the expected trend relationship with drug use. Lindenberg, C.S., et al. Competence and Drug Use: Conceptual Frameworks, Empirical Evidence and Measurement. Journal of Drug Education, 28(2), pp. 1997-1999, 1998.
Who Responds to Drug Abuse Surveys?
Researchers examined the personality and attitudinal characteristics of eager, reluctant, and nonresponders to a mailed longitudinal survey focusing on substance use through a series of logistic regression analyses. The characteristics that differentiate response patterns in men and women differ in terms of the relative importance of cooperation, behavioral low social conformity (substance use), and support of science/medicine. Socioeconomic status and attitudinal low social conformity did not differentiate among groups of responders, regardless of gender. Ullman, J.B., and Newcomb, M.D. Eager, Reluctant, and Nonresponders to a Mailed Longitudinal Survey: Attitudinal and Substance Use Characteristics Differentiate Respondents. Journal of Applied Social Psychology, 28, pp. 357-375, 1998.
Further Support for Memory Association as an Important Risk Factor
Previous research on the effect of memory associations has not thoroughly investigated how these associations may combine with personality in the prediction of alcohol and other drug use. Memory associations may interact with personality in these predictive effects, if some personality traits make the individual more susceptible to acting out the cognitive manifestations of these associations. Alternatively, personality and memory associations may be confounded. These alternatives were evaluated in a study of 554 adult men and women from a community sample. In addition, the nature of the effects of memory associations on drinking problems was evaluated. These effects may be indirect, through alcohol consumption, or more direct. The results showed that memory association directly and independently predicted alcohol consumption; these measures indirectly predicted problems from drinking, including drunk driving. None of the assessed personality variables moderated (interacted with) the predictive effects of memory association. The results are consistent with the view that memory associations influence behavior through cognitive processes that are not affected by personality traits or by cognitions emanating from such traits. The results provide further support for the memory association framework in addictive behaviors. Stacy, A.W., and Newcomb, M.D. Memory Association and Personality as Predictors of Alcohol Use: Mediation and Moderator Effects. Experimental & Clinical Psychopharmacology, 6, pp. 280-291, 1998.
Further Support for Memory Association as an Important Risk Factor
Previous research on the effect of memory associations has not thoroughly investigated how these associations may combine with personality in the prediction of alcohol and other drug use. Memory associations may interact with personality in these predictive effects, if some personality traits make the individual more susceptible to acting out the cognitive manifestations of these associations. Alternatively, personality and memory associations may be confounded. These alternatives were evaluated in a study of 554 adult men and women from a community sample. In addition, the nature of the effects of memory associations on drinking problems was evaluated. These effects may be indirect, through alcohol consumption, or more direct. The results showed that memory association directly and independently predicted alcohol consumption; these measures indirectly predicted problems from drinking, including drunk driving. None of the assessed personality variables moderated (interacted with) the predictive effects of memory association. The results are consistent with the view that memory associations influence behavior through cognitive processes that are not affected by personality traits or by cognitions emanating from such traits. The results provide further support for the memory association framework in addictive behaviors. Stacy, A.W., and Newcomb, M.D. Memory Association and Personality as Predictors of Alcohol Use: Mediation and Moderator Effects. Experimental & Clinical Psychopharmacology, 6, pp. 280-291, 1998.
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