Various surveys have identified a rapid increase in marijuana use during the 1990s, especially among youths. This raises a variety of questions about the future of the Nation’s drug problems. On one hand, the gateway theory posits that youthful use of alcohol and/or tobacco and marijuana tends to precede use of other illicit drugs like crack and heroin (see “The Gateway Theory”). The recent inc...

OBJECTIVE HIV infection and illicit drug use are each associated with diminished cognitive performance. This study examined the separate and interactive effects of HIV and recent illicit drug use on verbal memory, processing speed, and executive function in the multicenter Women's Interagency HIV Study. METHODS Participants included 952 HIV-infected and 443 HIV-uninfected women (mean age = 42...

Aim: To highlight the changes that may take place in the visual system of the class A drug abuser. Methods: A literature review was carried out of ocular/visual sequelae of the more common class A drugs. These include stimulants (cocaine and crack cocaine), narcotics (heroin, morphine, methadone) and hallucinogenics (ecstasy, lysergic acid diethylamide, magic mushrooms, mescaline, phencyclidine...

There are many ways that women support their use of crack cocaine, including sex-for-crack bartering and other forms of prostitution. Empirical studies conducted in the mid-1970s and in the mid-1980s in New York City, and in Chicago in the late 1980s to early 1990s are compared, analyzing similarities and differences between the contemporary crack-prostitution scene and previous prostitution sc...

In previous studies, heroin was shown to engender cocaine-like discriminative stimulus (DS) effects; however, the mechanisms underlying the cocaine-like effects of heroin are unknown. The present study evaluated the extent to which the shared DS effects of heroin and cocaine involve common monoaminergic mechanisms of action. In squirrel monkeys discriminating cocaine (0.3 mg/kg) from saline, he...

This paper studies polydrug use patterns in heroin and cocaine addicts. We use data on two experiments to measure the elasticity of several addictive drugs with respect to heroin and cocaine prices. Own and cross price elasticities are estimated while controlling for non-price related sources of variance. The results indicate that heroin addicts have an inelastic demand for heroin, complement h...

Sir, In Asia, Illicit opium and cannabis are produced mainly in Afghanistan, which makes major social and health problems for some countries, particularly Iran as the neighborhood. [1] In Iran, opium and hashish have been used for near 300 years, [2] but other drugs such as heroin, buprenorphine, cocaine, tramadol, and ecstasy are new drugs of abuse in this country. [3-6] Abuses of the new drug...

Cocaine and heroin often are abused together in a combination known as a "speedball," but relatively little is known about ways in which cocaine and heroin may interact to modify each other's abuse-related effects. The present study evaluated the discriminative stimulus effects of a speedball combination of cocaine and heroin. Three rhesus monkeys were trained to discriminate vehicle from a 10:...

Most Canadians believe that certain drugs cause catastrophic addictions in people who use them. This conventional belief is reflected in such familiar phrases as "crack cocaine is instantly addictive" or "heroin is so good, don't even try it once". It is also implied in the professional literature which routinely describes certain drugs as "addictive", "dependency producing", or "habit forming"...

BACKGROUND The use of both heroin and cocaine has been associated with asthma exacerbations. However, the magnitude of this effect has not been adequately described. The purpose of this study was to examine the association between cocaine or heroin use and asthma severity. METHODS We conducted a retrospective chart review of adult patients who had been admitted to an inner-city hospital and w...