David R Gibson

University of California, Davis, Davis, CA, United States

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Publications (12)27.99 Total impact

  • Kyung-Hee Choi, David R Gibson, Lei Han, Yaqi Guo
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    ABSTRACT: China is experiencing an emerging HIV epidemic among men who have sex with men (MSM). We investigated sexual risk, risk perception, HIV and condom knowledge, and utilization of prevention services in the first large sample of MSM recruited in Beijing. Four hundred eighty-two MSM were sampled from September 2001 to January 2002. Forty-nine percent of participants reported unprotected anal intercourse with men during the previous 6 months. However, only 15% perceived they are at risk for HIV and many had misconceptions about HIV transmission routes and limited knowledge about condoms. Less than one quarter obtained free condoms (24%) and condom lubricants (19%) in the past 2 years. Multiple logistic regression analysis showed that unprotected insertive anal intercourse was associated with not having a Beijing residence card, having six or more male sexual partners, not having sex with women, having a lifetime history of sexually transmitted diseases (STDs), and having never tested for HIV. Unprotected receptive anal intercourse was independently associated with having six or more male sexual partners, not having sex with women, having a lifetime history of STDs, having never tested for HIV, and having less exposure to HIV prevention services. In addition, 28% reported having sex with both men and women during the previous 6 months, and 11% had unprotected intercourse with both men and women. This finding suggests that MSM are a potential bridge of HIV transmission to heterosexual women (or vice versa) and that addressing the HIV prevention needs of MSM may benefit the wider population.
    AIDS Education and Prevention 03/2004; 16(1):19-30. · 1.59 Impact Factor
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    ABSTRACT: Among the illicit stimulants, cocaine and amphetamines are the most widely abused. Although these drugs have similar psychoactive properties and routes of administration, their duration of action and mechanism of action are different, as are the psychiatric problems that accompany their use. The authors explored whether these differences and results of urine drug testing were associated with differences in use of psychiatric inpatient services. The records of 2,357 patients admitted to a large county psychiatric emergency service were examined to determine whether patients admitted for amphetamine-related or cocaine-related disorders differed in rates of transfer to an inpatient psychiatric ward or in length of stay on the ward after transfer. The authors also examined whether positive or negative results of urine drug screens predicted transfer or length of stay. Patients with amphetamine-related disorders were more than a third more likely than patients with cocaine-related disorders to be transferred to the inpatient ward. Patients with negative urine screens were a third more likely than those with positive screens to be transferred and stayed slightly longer on the ward after transfer. Patients with cocaine-related disorders stayed slightly longer on the ward than patients with amphetamine-related disorders. Patients with amphetamine-related disorders have higher rates of psychiatric hospitalization than patients with cocaine-related disorders. Diagnostic uncertainty and other factors may also influence transfer rates and subsequent length of stay.
    Psychiatric Services 12/2002; 53(11):1461-6. · 2.01 Impact Factor
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    ABSTRACT: Studies based on animal models report that methamphetamine (MA) abuse diminishes dopamine (DA) and serotonin innervation in frontal brain regions. In this in vivo human study, we used proton magnetic resonance spectroscopy (MRS), which yields measures of N-acetyl-aspartate (NAA), a marker of living neurons, to examine frontal brain regions possibly affected by methamphetamine dependence (MD). We tested the hypothesis that MD subjects would exhibit abnormally low levels of NAA, referenced to creatine (Cr), in anterior cingulate gray matter. We further hypothesized that the primary visual cortex, which receives relatively less DA innervation than the frontal brain regions, would show normal NAA/Cr ratios in MD subjects. Subjects included nine MD men (mean+/-standard deviation (S.D.)=32.5+/-6.4 years) and nine age-matched control men (mean+/-S.D.=32.7+/-6.8 years). The MD subjects were MA-free for 4-13 weeks. Proton MRS metabolites were expressed as ratios of creatine; the absolute values of which did not distinguish controls and MD subjects. With regard to metabolite ratios, the MD men had significantly lower NAA/Cr in the cingulum (mean+/-standard error (S.E.): control=1.46+/-0.03; MD=1.30+/-0.03; Mann-Whitney P=0.01) but not in the visual cortex (mean+/-S.E.: control=1.64+/-0.06; MD=1.69+/-11; Mann-Whitney P=0.52) relative to controls. These results provide evidence for NAA/Cr deficit that is selective to the anterior cingulum, at least with respect to visual cortex, in MD subjects. The neuronal compromise that these changes reflect may contribute to the attentional deficits and dampened reward system in MD.
    Psychiatry Research 12/2002; 116(1-2):43-52. · 2.68 Impact Factor
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    ABSTRACT: We report results of a community study of syringe exchange that compared the HIV risk behavior of exchange clients with that of nonclients. A prospective cohort of 259 untreated injecting drug users (IDUs) was followed a mean of 10.7 months after baseline. In assessing whether HIV risk behavior at follow-up was associated with study participants' follow-up use of the exchange, we controlled their baseline risk behavior and exchange use as markers of risk-taking tendency in addition to other potential confounders. We also examined whether there was a differential benefit of exchange use for IDUs with versus those without access to other sources of syringes. Both univariate and multivariate analyses revealed a more than twofold decreased odds of HIV risk behavior associated with use of the exchange. In a second multivariate analysis, which examined the interaction of exchange use with access to other sources of syringes, the odds of HIV risk behavior were decreased more than sixfold for IDUs without other sources. We conclude that use of the exchange had a substantial protective effect against HIV risk behavior and may have been especially critical for IDUs without other sources of syringes.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 11/2002; 31(2):237-42. · 4.65 Impact Factor
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    ABSTRACT: Chronic methamphetamine abuse is associated with disruption of frontostriatal function involving serotonin and dopamine circuitry. Clinically, methamphetamine-dependent (MD) individuals are highly distractible and have difficulty focussing. Here, we used a computerized single-trial version of the Stroop Test to examine selective attention and priming in MD. Subject groups comprised eight MD men (31.7+/-7.2 years of age), who had used methamphetamine for 15.75+/-8.4 years but were currently abstinent for 2-4 months, and 12 controls (35.7+9.7 years of age). Compared with the control group, the MD group exhibited significantly greater interference (P<0.05) despite intact priming. Error rates did not differ between the groups. This preliminary finding of reduced cognitive inhibition in MD individuals is consistent with the distractibility they show clinically. Furthermore, the dissociation between explicit attentional performance and priming effects suggests that some attentional functions are not as affected by long-term methamphetamine use as others.
    Psychiatry Research 08/2002; 111(1):65-74. · 2.68 Impact Factor
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    ABSTRACT: Studies based on animal models report that methamphetamine (MA) abuse diminishes dopamine (DA) and serotonin innervation in frontal brain regions. In this in vivo human study, we used proton magnetic resonance spectroscopy (MRS), which yields measures of N-acetyl-aspartate (NAA), a marker of living neurons, to examine frontal brain regions possibly affected by methamphetamine dependence (MD). We tested the hypothesis that MD subjects would exhibit abnormally low levels of NAA, referenced to creatine (Cr), in anterior cingulate gray matter. We further hypothesized that the primary visual cortex, which receives relatively less DA innervation than the frontal brain regions, would show normal NAA/Cr ratios in MD subjects. Subjects included nine MD men (mean±standard deviation (S.D.)=32.5±6.4 years) and nine age-matched control men (mean±S.D.=32.7±6.8 years). The MD subjects were MA-free for 4–13 weeks. Proton MRS metabolites were expressed as ratios of creatine; the absolute values of which did not distinguish controls and MD subjects. With regard to metabolite ratios, the MD men had significantly lower NAA/Cr in the cingulum (mean±standard error (S.E.): control=1.46±0.03; MD=1.30±0.03; Mann–Whitney P=0.01) but not in the visual cortex (mean±S.E.: control=1.64±0.06; MD=1.69±11; Mann–Whitney P=0.52) relative to controls. These results provide evidence for NAA/Cr deficit that is selective to the anterior cingulum, at least with respect to visual cortex, in MD subjects. The neuronal compromise that these changes reflect may contribute to the attentional deficits and dampened reward system in MD.
    Psychiatry Research Neuroimaging 01/2002; 116(1):43-52. · 3.36 Impact Factor
  • David R Gibson, Martin H Leamon, Neil Flynn
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    ABSTRACT: Methamphetamine use is an increasingly serious public health problem in California and other parts of the country. Despite sensationalistic media attention, however, very little is known about users of this clandestinely consumed drug. Employing methods known as Rapid Assessment and Response, the authors describe the epidemiology and public health implications of methamphetamine use in California's Central Valley, with a focus on Sacramento, which many social indicators suggest has been more severely affected by methamphetamine than any city in the nation. Data sources for this report include interviews with drug users, statistical reports, epidemiologic studies, and local informed expert opinion. In their social demography, methamphetamine users in the Central Valley are in marked contrast to those of coastal cities such as Seattle and San Francisco, being largely heterosexual, and of mixed racial/ethnic heritage. Three-quarters or more initiate their use of the drug while still in their teens, with more than a quarter beginning use before the age of 15. Many of these rapidly gravitate to regular use, and continue using well into their thirties. Methamphetamine users are at much higher risk of infection with HIV than opiate users, particularly if they inject. Partly because methamphetamine enhances libido, users of the drug typically also have many more sexual partners. Not surprisingly, data indicate that methamphetamine users are more likely than heroin users to be HIV-infected. Methamphetamine appears to be less of a street drug than heroin, complicating efforts at street outreach. However, because it is typically used in social settings, a social or diffusion approach to HIV prevention might be particularly promising.
    Journal of psychoactive drugs 01/2002; 34(3):313-9. · 1.10 Impact Factor
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    ABSTRACT: We evaluated the behavioral effects of brief counseling designed to assist injecting drug users in problem-solving situations in which they engage, or are tempted to engage, in practices that place them at risk of infection with HIV. Two hundred ninety-five (295) heroin detoxification clients were randomly assigned to receive either 50 min of the experimental preventive counseling or a packet of educational brochures. Follow-up interviews were conducted 3 and 12 months after randomization to assess the effects of counseling versus brochures. In a follow-up study with 109 clients, the experimental counseling was modified to be conducted in the context of notifying drug users of their HIV test results. In the follow-up study, we conducted standard pretest counseling before randomizing subjects to receive or not to receive the 50 min of experimental counseling. Follow-up interviews conducted 6 and 12 months after randomization assessed the impact of the experimental counseling versus standard pretest counseling. Substantial decreases in injection-related and sexual risk behavior were observed among subjects in both conditions in both studies. The decreases were for the most part sustained to 12-month follow-up interviews. The results suggest that many drug users may not require intensive counseling to reduce or eliminate high-risk practices. We determined that the reductions in risk behavior for both groups and both studies were probably not the result of secular historical trends, contamination of the experimental by the comparison group, volunteer bias, or regression or maturation effects, but very likely were in part a consequence of participating in research. Implications include the potential preventive effectiveness of a widely practiced form of health promotion known as the health risk assessment.
    AIDS and Behavior 02/1999; 3(1):3-12. · 3.49 Impact Factor
  • David R. Gibson, Esther S. Hudes, David Donovan
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    ABSTRACT: One of the most difficult problems of behavioral research on human sexuality and drug use is its reliance on people's self‐reports about their behavior. Given the essentially private nature of sexual and drug‐taking practices, many aspects of these practices are difficult, even impossible, to validate. The lack of a gold standard for self‐reports is particularly troubling with regard to HIV‐related behavior. To the extent that self‐reports are affected by response bias, the prevalence of high risk practices will be underestimated, hindering efforts to slow the spread of HIV. In this paper the extent of response bias in seven measures of high‐risk injection‐related and sexual behaviors is estimated. Self‐reported high‐risk injection practices may be significantly to substantially underreported due to response bias, whereas self‐reports of some high‐risk sexual practices do not appear to be contaminated by response bias. In regression analyses, the response bias in self‐reports of needle sharing and other high‐risk injection practices was modeled, and estimates of the probable actual prevalence of these practices derived. In situations in which behavioral self‐reports cannot be validated, such derivations may help in arriving at more accurate estimates of behavior.
    Journal of Sex Research - J SEX RES. 01/1999; 36(1):96-101.
  • AIDS 10/1991; 5(9):1149-50. · 6.41 Impact Factor
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    ABSTRACT: Intravenous drug users (N = 88) and their sexual partners (N = 45) were randomly assigned to either a brief counseling intervention or an information-brochure only condition (aimed at reducing behavioral risk for HIV infection). At 10 day follow-up, intravenous drug users exposed to brief counseling were more knowledgeable about risk behaviors, and reported higher levels of self-efficacy and communication skill, and more frequent use of condoms and sterilisation of needles. At 90 day follow-up, intravenous drug users were more accepting of guidelines to reduce sex-related risk and reported greater self-efficacy in relation to drugs. Sexual partners who received brief counseling showed a small reduction in unprotected sex (at 90-day follow-up), while those receiving brochures were slightly less likely to use condoms. Methodological problems of the study are discussed.
    Counselling Psychology Quarterly 01/1989; 2(1):15-19.
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    ABSTRACT: In this book, we aim to disseminate research-validated information about how to prevent HIV [human immunodeficiency virus] infection among drug users and their sexual partners. The book is for practitioners and scientists coping with the problems of drug abuse and AIDS [acquired immune deficiency syndrome], and for those involved in the search for AIDS prevention techniques with other population groups such as adolescents. It comes from our experience in developing and evaluating AIDS prevention programs with drug abusers and their sexual partners. The health professionals who work with drug users have many questions about what they can do to slow the spread of HIV infection among their patients and their patients' intimate partners and children. . . . What can they do to prevent the spread of AIDS in their clinics, in their professional practices, or among friends who may be risking HIV infection by having unsafe sexual encounters? The book addresses these issues. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Publication Stats

424 Citations
27.99 Total Impact Points

Institutions

  • 2002
    • University of California, Davis
      • Department of Psychiatry and Behavioral Medicine
      Davis, CA, United States
    • Lawrence Berkeley National Laboratory
      Berkeley, California, United States
  • 1999
    • University of California, San Francisco
      • Division of Hospital Medicine
      San Francisco, California, United States