Clinical Textbook of Addictive Disorders 3rd ed - R. Frances, S. Miller, A. Mack (Guilford, 2005) WW

418 IV. SPECIAL POPULATIONSsion. We have found that comorbid major depression may account for many ofthe immune changes found in alcoholics (Schleifer, Keller, & Czaja, 2003). Itshould also be noted that exposure to alcohol and other drugs may influencethe symptomatic and pathological course of HIV-associated CNS disturbanceeither through additive effects on CNS function (Fein, Biggins, & MacKay,1995) or neurotoxic interactions with the viral effects (Tabakoff, 1994). Alcoholconsumption remains a risk factor for medication adherence and can modifyliver metabolism, both of which could lead to drug-resistant virus (Kresinaet al., 2002). Other researchers have found alcohol consumption prevalent intheir HIV-positive, drug-using population, and have found that it significantlynegatively impacts immunological and viral response to ART (Miguez, Shor-Posner, Morales, Rodriguez, & Burbano, 2003).MarijuanaThe contribution of cannabinoid use to human disease remains unclear and is asubject of considerable debate. A large study in California suggested that mortalityrates in the general population are not increased by marijuana use;however, marijuana use was associated with increased mortality in personswith HIV disease (Sidney, Beck, Tekawa, Quesenberry, & Friedman, 1997).Whether these reflect direct effects on the disease process or lifestyle differencesassociated with marijuana use remains to be determined (Klein, Newton,Snella, & Friedman, 2001; Sidney et al., 1997). Both the clinical and theexperimental data remain unclear as to whether marijuana use contributes negativelyto the course of HIV disease. Correspondingly, it is unclear whethercannabinoids are useful adjuncts to the management of AIDS-related symptomsand syndromes, such as the AIDS-wasting syndrome, nausea, vomiting,anorexia, and glaucoma.StimulantsStimulant users, particularly crack cocaine smokers or injecting stimulant users(cocaine, amphetamine) incur considerable risk for HIV. There is little definitiveevidence of cocaine effects on T-cell function (MacGregor, 1988). In contrast,a few studies have associated both cocaine and amphetamines withincreased NK activity (Swerdlow et al., 1991; Van Dyke, Stesin, Jones,Chuntharapai, & Seaman, 1986). Considering the prevalence of cocaine andother stimulant use, and its role as a behavioral risk factor for HIV transmission,the effects of cocaine use and withdrawal require further investigation. Onestudy reported only limited effects of cocaine withdrawal on immune-relatedmarkers in pregnant women (Johnson, Knisely, Christmas, Schnoll, & Ruddy,1996). Finally, the role of the most ubiquitous substance of abuse, tobacco, cannotbe underestimated. Tobacco exposure has pervasive effects on health,