Research Findings - Research on AIDS and Other Medical Consequences of Drug Abuse - Non-AIDS Research

Welfare and Work Outcomes after Substance Abuse Treatment

Employment and welfare outcomes are investigated for women who received both welfare and substance abuse treatment in Florida from 1994 to 1999. By linking information from three statewide administrative databases, the authors identify 4,236 women who meet both criteria. Over the study period, there was a significant increase in the proportion of women moving from welfare to work. Predictors of post treatment employment include demographic characteristics, treatment related characteristics, and working during the month of admission. Both completion of treatment and length of time in treatment are associated with employment. Metsch, L.R., Pereyra, M., Miles, C. and McCoy, C.B. Social Service Review, 77(2), pp. 2003.

Met and Unmet Need for Dental Services Among Active Drug Users in Miami, Florida

This study considers both met and unmet need for dental services among chronic drug users in Miami, Florida, and compares them with non-drug users recruited from the same neighborhoods (N=1,479). Three primary findings emerged: (1) dental problems are among the most frequently reported health problems, (2) drug use is independently associated with need for dental services, and (3) injection drug use is independently associated with increased odds of unmet need for dental services. These findings suggest that policies that increase access to dental services for drug user and other disadvantaged groups are needed. These services could be integrated into existing behavioral health programs already targeting active drug users. Metsch, L.R., Crandall, L., Wohler-Torres, B., Miles, C., Chitwood, D.D., and McCoy, C.B. The Journal of Behavioral Health Services & Research (JBHSR), 29(2), pp. 176-188, 2002.

Hepatitis C Virus Infection Among Noninjecting Drug Users in New York City

The prevalence of hepatitis C virus (HCV) infection among noninjecting drug users has been reported to be higher than in the general population, but the reasons for this observation remain unclear. Noninjecting drug users aged 15-40 years and who used drugs for no longer than 10 years were enrolled in the study. The participants were interviewed about risk behaviors and had specimens drawn for serological testing. Of 276 enrolled, 4.7% were infected with HCV. Drug users who had ever sniffed or snorted heroin in combination with cocaine were significantly more likely to be infected with HCV compared with those who never sniffed or snorted heroin with cocaine. No other drug use or sexual risk behaviors were found to be associated with HCV infection. These findings suggest that sniffing or snorting heroin with cocaine may explain the increase frequently found in HCV infection among noninjectors, but further studies are necessary. Koblin, B.A., Factor, S.H., Wu, Y. and Vlahov, D. J Med Virol.,70(3), pp. 387-390, July 2003.

Hepatitis C Virus Infection and Incident Type 2 Diabetes

Although hepatitis C virus (HCV) infection is more common among adults with type 2 diabetes, it is uncertain whether HCV precedes the development of diabetes. Thus, we performed a prospective (case-cohort) analysis to examine if persons who acquired type 2 diabetes were more likely to have had antecedent HCV infection when enrolled in a community-based cohort of men and women between the ages of 44 and 65 in the United States (Atherosclerosis Risk in Communities Study [ARIC]). Among 1,084 adults free of diabetes at baseline, 548 developed diabetes over 9 years of follow-up evaluation. Incident cases of diabetes were identified by using fasting glucose and medical history and HCV antibodies were assessed at baseline. A priori, persons were categorized as low-risk or high-risk for diabetes based on their age and body mass index, factors that appeared to modify the type 2 diabetes-HCV infection incidence estimates. The overall prevalence of HCV in this population was 0.8%. Among those at high risk for diabetes, persons with HCV infection were more than 11 times as likely as those without HCV infection to develop diabetes (relative hazard, 11.58; 95% confidence interval, 1.39-96.6). Among those at low risk, no increased incidence of diabetes was detected among HCV-infected persons (relative hazard, 0.48; 95% confidence interval, 0.05-4.40). In conclusion, pre-existing HCV infection may increase the risk for type 2 diabetes in persons with recognized diabetes risk factors. Additional larger prospective evaluations are needed to confirm these preliminary findings. Mehta, S.H., Brancati, F.L., Strathdee, S.A., Pankow, J.S., Netski, D., Coresh, J., Szklo, M. and Thomas, D.L. Hepatology, 38(1), pp. 50-56, July 2003.

The Effect of HAART and HCV Infection on the Development of Hyperglycemia Among HIV-Infected Persons

The objective of this study was to examine the prevalence and incidence of hyperglycemia among HIV-infected patients by hepatitis C virus (HCV) infection and type of highly active antiretroviral therapy (HAART). A retrospective cohort analysis was performed of 1,230 persons on their first HAART regimen who had at least 1 random glucose measurement before and during antiretroviral therapy. The prevalence of hyperglycemia and the incidence of hyperglycemia were compared among persons with and without HCV infection while on a protease inhibitor (PI)-containing HAART regimen, a non-nucleoside reverse transcriptase inhibitor (NNRTI)-containing regimen, or a regimen that contained both a PI and an NNRTI. Hyperglycemia was defined as either 2 random glucose levels > 11.1 mM (200 mg/dL) or documentation of the diagnosis of diabetes in the medical record. The prevalence of hyperglycemia was significantly higher in HCV-coinfected (5.9%) than HCV-uninfected persons (3.3%, P = 0.02). Among persons receiving HAART, both HCV co-infection (adjusted relative hazard [ARH], 2.28; 95% CI, 1.23-4.22) and PI use (ARH, 5.02; 95% CI, 1.39-18.16) were independent risk factors of developing hyperglycemia. The incidence of hyperglycemia was highest among HCV-coinfected persons receiving a PI (5.6 cases per 100-person years) and only 1 person who was neither HCV-infected nor receiving a PI developed hyperglycemia. In this urban HIV cohort, the risk of hyperglycemia was increased in HCV-coinfected patients and those prescribed a PI. Mehta, S.H., Moore, R.D., Thomas, D.L., Chaisson, R.E. and Sulkowski, M.S. J Acquir Immune Defic Syndr. 33(5), pp. 577-584, August 15, 2003.

Differential Effects on Cognitive Functioning in 13- to 16-Year-Olds Prenatally Exposed to Cigarettes and Marijuana

The ongoing effects of prenatal cigarette and marijuana exposure were explored in a study conducted by Fried and colleagues. Assessments were carried out in the areas of general intelligence, achievement, memory, and aspects of executive functioning. Maternal cigarette smoking during pregnancy was categorized into nonsmoking, light, and heavy ($16 mg nicotine/day), while maternal average marihuana use across pregnancy was categorized into two groups: no use plus infrequent/ moderate use, and heavy use ($6 joints/week). After controlling for confounding variables, the strongest relationship between maternal cigarette use and cognitive variables was seen with overall general intelligence and aspects of auditory functioning. Prenatal marijuana exposure was negatively associated with tasks that required visual memory, analysis, and integration. The areas that appear vulnerable to prenatal exposure to either cigarettes or marijuana are the same that were identified at earlier ages, and these two drugs continue to differentially impact varying aspects of cognition. Fried, P., Watkinson, B., and Gray, R. Differential Effects on Cognitive Functioning in 13- to 16-Year-Olds Prenatally Exposed to Cigarettes and Marijuana. Neurotoxicology and Teratology, 25, pp. 427-436, 2003.

Influence of Prenatal Cocaine Exposure on Early Language Development

Researchers at the University of Miami have recently reported effects of prenatal cocaine exposure on early language development. The Miami Prenatal Cocaine Study prospectively enrolled 476 African-American infants categorized as cocaine-exposed or non-cocaine exposed. The Bayley Scales of Infant Development were administered at 4, 8, 12, 18, and 24 months. At 3 years, the Clinical Evaluation of Language Fundamentals-Preschool was administered. Information was also collected from the primary caregiver at the time of child assessment. Prenatal substance exposure was measured by the number of cigarettes smoked, number of marijuana cigarettes smoked, number of drinks of beer, wine, or hard liquor, and number of cocaine lines or rocks recorded in increments of usual daily dose, usual days per week, and number of weeks used. Longitudinal analyses indicated evidence for a subtle, consistent pattern of cocaine-associated deficits in language functioning over the six intervals assessed during the first three years of life. This association remained stable after considering prenatal exposure to other substances, and important social-environmental factors. The investigators suggest that these subtle deficits may have important ramifications for long-term academic and social adaptation, especially when considered within the broader context of additional potential risk factors. Morrow, C.E., Bandstra, E.S., Anthony, J.C., Ofir, A.Y., Xue, L., and Reyes, M.B. Influence of Prenatal Cocaine Exposure on Early Language Development: Longitudinal Findings from Four Months to Three Years of Age. Developmental and Behavioral Pediatrics, 24(1), pp. 39-50, 2003.

Cannabis Withdrawal Syndrome

Budney and his colleagues at the University of Vermont have presented an excellent overview of the scientific and clinical literature on cannabis abstinence effects providing a critical examination of extant data relevant to determining the validity and significance of a cannabis withdrawal syndrome. They have reviewed briefly the animal laboratory literature followed by more detailed discussion of human laboratory and clinical studies. Converging evidence from the basic laboratory to the clinic indicates that a reliable withdrawal syndrome follows discontinuation of chronic, heavy use of cannabis or THC. Common symptoms are primarily emotional and behavioral, although appetite change, weight loss, and physical discomfort are also frequently reported. The onset and time course of these symptoms appear similar to that of other substance withdrawal syndromes. Their magnitude and severity appears substantial suggesting that the syndrome has clinical importance. They have proposed criteria for cannabis withdrawal syndrome, have discussed limitations of existing research, and identified areas for future basic and clinical research on marijuana. Budney, A., Hughes, J.R., Moore, B.A. and Vandrey, R. A Review of the Validity and Significance of the Cannabis Withdrawal Syndrome, Archives of General Psychiatry, August 2003.

Chronic Pain Among Patients in MMTP and Residential Treatment Facilities

Little is known about the prevalence and characteristics of chronic pain among patients with different types of chemical dependency. In this study, researchers estimated the prevalence and examined the characteristics of chronic severe pain in chemically dependent populations receiving methadone maintenance or inpatient residential treatment. Participants included representative samples of 390 patients from 2 methadone maintenance treatment programs (MMTPs) and 531 patients from 13 short-term residential substance abuse treatment (inpatient) programs, all in New York State, surveyed in late 2000 and early 2001. The main outcome measures were prevalence of chronic severe pain, defined as pain that persisted for more than 6 months and was of moderate to severe intensity or that significantly interfered with daily activities. Thirty-seven percent of MMTP patients and 24% of inpatients experienced chronic severe pain, and 80% of MMTP patients and 78% of inpatients reported pain of any type or duration during the past week. Among those with chronic severe pain, 65% of MMTP patients and 48% of inpatients reported high levels of pain-related interference in physical and psychosocial functioning. Among MMTP patients, correlates of chronic pain in a multivariate model were age, chronic illness, lifetime psychiatric illness, psychiatric distress, and time in treatment. Among inpatients, the correlates of chronic pain were race, drug craving, chronic illness, and psychiatric distress. Among those with chronic severe pain, inpatients were significantly more likely than MMTP patients to have used illicit drugs, as well as alcohol, to treat their pain complaint (51% vs 34%, p = .005) but were less likely to have been prescribed pain medications (52% vs 67%, p = .01). Chronic severe pain is prevalent among patients in substance abuse treatment, especially MMTP patients. Pain is associated with functional impairment and correlates of pain vary with the population. Self-medication for pain with psychoactive drugs appears especially problematic among substance users who enroll in drug-free treatment programs. Substance abuse treatment programs need to develop comprehensive and structured pain management programs. Rosenblum, A., Joseph, H., Fong, C., Kipnis, S., Cleland, C. and Portenoy, R. Prevalence and Characteristics of Chronic Pain Among Chemically Dependent Patients in Methadone Maintenance and Residential Treatment Facilities, JAMA, 289(18), pp. 2370-2378, 2003.

Chronic Drug Use and Reproductive Health Care among Low-Income Women in Miami

In this study, researchers interviewed a stratified, network-referred sample of chronic drug-using women (CDUs) and socially and ethnically similar women who were not CDUs about reproductive health issues. Women who were not CDUs were significantly more likely to report a regular source of health care than CDUs. About one third of each group reported experiencing reproductive health problems (other than pregnancy) in the 12 months preceding their interview. Chronic drug users were twice as likely to report that these problems remained untreated. Measures of use of preventive services (physical exam, breast exam, pelvic exam, family planning visit) consistently showed lower use by CDUs. A higher proportion of women who were not CDUs reported pregnancies in the 12 months preceding interview. The 32 pregnant CDUs were much less likely to have received prenatal care than the 42 pregnant women who were not CDUs. For women who reported a pregnancy in the year preceding interview, logistic regression analysis showed a strong and robust negative effect of being a CDU on receiving prenatal care even when the effects of having a usual source of care and having third-party coverage were controlled. Crandall, L., Metsch, L., McCoy, C., Chitwood, D. and Tobias, H. Chronic Drug Use and Reproductive Health Care among Low-Income Women in Miami, Florida: A Comparative Study of Access, Need, and Utilization, J Behav Health Serv Res., 30(3), pp. 321-331, July-September 2003.