David R. Gibson

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

Are you David R. Gibson?

Claim your profile

Publications (23)63.12 Total impact

  • Kyung-Hee Choi, David R Gibson, Lei Han, Yaqi Guo
    [Show abstract] [Hide abstract]
    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
  • [Show abstract] [Hide abstract]
    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. · 1.99 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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
  • [Show abstract] [Hide abstract]
    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. · 4.39 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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 11/2002; 116(1):43-52. · 2.83 Impact Factor
  • David R Gibson, Martin H Leamon, Neil Flynn
    [Show abstract] [Hide abstract]
    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 09/2002; 34(3):313-9. · 1.10 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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
  • D R Gibson, N M Flynn, D Perales
    AIDS 08/2001; 15(11):1329-41. · 6.56 Impact Factor
  • D R Gibson, N M Flynn, J J McCarthy
    AIDS 11/1999; 13(14):1807-18. · 6.56 Impact Factor
  • [Show abstract] [Hide abstract]
    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
    [Show abstract] [Hide abstract]
    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.
    The Journal of Sex Research 02/1999; 36(1):96-101. · 2.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In two trials of a small-group AIDS prevention approach, 50 methadone maintenance patients and 98 heroin abusers in outpatient detoxification were randomly assigned to experimental or comparison conditions. Experimental condition subjects received a 6-hour, small-group intervention that aimed to improve their knowledge and attitudes about AIDS, skills in syringe sterilization and condom use, and changing high-risk needle use and sexual behaviors. Comparison subjects received a set of written materials about AIDS. At posttest and 3-month follow-ups, experimental condition subjects in both maintenance and detoxification demonstrated greater knowledge of AIDS and risk reduction practices and improved skill in demonstrating condom use. Although outpatient detoxification subjects displayed considerably more risk behaviors at study outset, the intervention's effect appeared to be more robust in methadone maintenance patients. The relative lack of impact on subjects' behaviors points out that more potent, sustained interventions need to be developed to slow the spread of HIV among injecting drug users.
    AIDS Education and Prevention 05/1994; 6(2):95-112. · 1.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study examined the relationship between health beliefs and needle sharing in a sample of 226 heroin detoxification clients. Zero-order correlations revealed that needle sharing was positively associated with perceived susceptibility and AIDS anxiety, and negatively associated with self-efficacy and communication skill in negotiating safe needle practices. Logistic regression analysis showed that demographic and situational factors also play a role in needle sharing. White race and injection of drugs in shooting galleries or other public places increase the odds of sharing a "dirty" needle, while that probability decreases sharply as a function of drug users' self-efficacy. This last finding suggests that preventive clinical interventions such as counseling or psychoeducational groups maybe needed to help drug users develop confidence in resisting needle sharing.
    The International journal of the addictions 09/1993; 28(10):973-81.
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study examined the degree that the distribution of coupons brought drug users at risk of HIV infection into outpatient detoxification treatment. Demographic characteristics and outcome indicators were compared for patients recruited through coupon redemption (n = 238) versus other referral channels (n = 1129). Significantly more coupon subjects had no previous drug treatment, compared with non-coupon subjects (28% vs. 13%), had shared needles in the previous 30 days (39% vs. 31%) and more were ethnic minorities and men. Length of treatment stay and program completion rates did not differ between the groups. Within a year of the coupon project's end 43% of coupon subjects returned to the treatment program. Results suggest untreated heroin users will utilize drug treatment if more is available.
    Drug and Alcohol Dependence 03/1993; 31(3):247-52. · 3.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Twenty-six pairs of heroin addicts applying for methadone maintenance treatment and their family members were interviewed before being admitted to a drug treatment program and 3 months after entry into treatment to determine whether treatment resulted in changes in family or individual functioning. Results revealed a considerable lessening of family and patient problems in the first months of drug treatment. Family members and patients reported significantly fewer family crises and family difficulties with the patient. Both family members and patients reported improvement on several mood indicators and significant lessening of the patient's family/social problems and drug problems.
    The International journal of the addictions 02/1992; 27(8):961-78.
  • AIDS 10/1991; 5(9):1149-50. · 6.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An unprecedented number of human sexuality studies have been initiated in response to the acquired immune deficiency syndrome (AIDS) epidemic. Unfortunately, methodological developments in the field of sex research have been slow in meeting the demands of AIDS investigations focusing on the diverse populations at risk for infection with the human immunodeficiency virus (e.g., adolescents, gay men, intravenous-drug users, ethnic minorities, elderly transfusees). In this article, we review and integrate current literature on measurement error and participation bias in sex research, with an emphasis on collecting sexual information in the context of AIDS. The relevance of these findings for AIDS-related sex research is discussed, and recommendations are made to guide future investigations.
    Psychological Bulletin 12/1990; 108(3):339-62. · 14.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The AIDS (Acquired Immunodeficiency Syndrome) epidemic has brought increased attention to the problems investigators face in collecting highly sensitive information. In this context, literature on response bias in sex research is reviewed with particular attention to test-retest reliability and nonresponse issues. The influence of various task, interviewer, and respondent motivation variables on response bias in sex surveys is discussed. Recommendations for decreasing response bias are made. These recommendations are limited in that there is need for additional methodological studies among low socioeconomic class respondents, ethnic minorities, non-English speaking people, and other subpopulations of interest to AIDS investigators (e.g., IVDUs, prostitutes). Suggestions for accomplishing this goal are made.
    Evaluation and Program Planning 02/1990; · 0.90 Impact Factor
  • Source
    NIDA research monograph 02/1989; 95:405-6.
  • [Show abstract] [Hide abstract]
    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.

Publication Stats

1k Citations
63.12 Total Impact Points

Institutions

  • 2002
    • University of California, Davis
      • Department of Internal Medicine
      Davis, California, United States
    • Lawrence Berkeley National Laboratory
      Berkeley, California, United States
  • 1985–1999
    • University of California, San Francisco
      • • Division of Hospital Medicine
      • • Center for AIDS Prevention Studies
      • • Department of Psychiatry
      San Francisco, California, United States