Recent progress in the neurotoxicology of natural drugs associated with dependence or addiction, their endogenous agonists and receptors.
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Nicotine in tobacco, tetrahydrocannabinol (delta 9-THC) in marijuana and morphine in opium are well known as drugs associated with dependence or addiction. Endogenous active substances that mimic the effects of the natural drugs and their respective receptors have been found in the mammalian central nervous system (CNS). Such active substances and receptors include acetylcholine (ACh) and the nicotinic ACh receptor (nAChR) for nicotine, anandamide and CB1 for delta 9-THC, and endomorphins (1 and 2) and the mu (OP3) opioid receptor for morphine, respectively. Considerable progress has been made in studies on neurotoxicity, in terms of the habituation, dependence and withdrawal phenomena associated with these drugs and with respect to correlations with endogenous active substances and their receptors. In this article we shall review recent findings related to the neurotoxicity of tobacco, marijuana and opium, and their toxic ingredients, nicotine, delta 9-THC and morphine in relation to their respective endogenous agents and receptors in the CNS. (+info)
Use of illicit drugs among high-school students in Jamaica.
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Reported are the results of a survey to assess the prevalence of illicit drug use among high-school students in Jamaica. A total of 2417 high-school students in 26 schools were covered: 1063 boys and 1354 girls of whom 1317 were grade-10 students (mean age 15.7 years) and 1100 were grade-11 students (mean age 16.8 years). Of the students, 1072 and 1345 were from rural and urban schools, respectively, while 1126 and 1291 were children of parents who were professionals and nonprofessionals, respectively. The following drugs were used by the students: marijuana (10.2%), cocaine (2.2%), heroin (1.5%) and opium (1.2%). Illicit drug use among males, urban students and children of professionals was higher than that among females, rural students and children of nonprofessionals, respectively. (+info)
Cannabis use and cognitive decline in persons under 65 years of age.
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The purpose of this study was to investigate possible adverse effects of cannabis use on cognitive decline after 12 years in persons under age 65 years. This was a follow-up study of a probability sample of the adult household residents of East Baltimore. The analyses included 1,318 participants in the Baltimore, Maryland, portion of the Epidemiologic Catchment Area study who completed the Mini-Mental State Examination (MMSE) during three study waves in 1981, 1982, and 1993-1996. Individual MMSE score differences between waves 2 and 3 were calculated for each study participant. After 12 years, study participants' scores declined a mean of 1.20 points on the MMSE (standard deviation 1.90), with 66% having scores that declined by at least one point. Significant numbers of scores declined by three points or more (15% of participants in the 18-29 age group). There were no significant differences in cognitive decline between heavy users, light users, and nonusers of cannabis. There were also no male-female differences in cognitive decline in relation to cannabis use. The authors conclude that over long time periods, in persons under age 65 years, cognitive decline occurs in all age groups. This decline is closely associated with aging and educational level but does not appear to be associated with cannabis use. (+info)
Alcohol and other psychoactive drugs in trauma patients aged 10-14 years.
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OBJECTIVE: To examine the prevalence of alcohol and/or other psychoactive drugs, such as marijuana and cocaine (AODs), involved in preteen trauma patients. METHODS: Toxicological testing results were analyzed for 1356 trauma patients aged 10-14 years recorded in the National Pediatric Trauma Registry for the years 1990-95. RESULTS: Of the 1356 patients who received toxicological screening at the time of admission, 116 (9%) were positive for AODs. AOD involvement increased with age. Patients with pre-existing mental disorders were nearly three times as likely as other patients to be AOD positive (23% v 8%, p < 0.01). AOD involvement was more prevalent in intentional injuries and in injuries that occurred at home. CONCLUSIONS: AODs in preteen trauma are of valid concern, in particular among patients with mental disorders or intentional injuries. The role of AODs in childhood injuries needs to be further examined using standard screening instruments and representative study samples. (+info)
The risks for late adolescence of early adolescent marijuana use.
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OBJECTIVES: The purpose of this study was to assess the relation of early adolescent marijuana use to late adolescent problem behaviors, drug-related attitudes, drug problems, and sibling and peer problem behavior. METHODS: African American (n = 627) and Puerto Rican (n = 555) youths completed questionnaires in their classrooms initially and were individually interviewed 5 years later. Logistic regression analysis estimated increases in the risk of behaviors or attitudes in late adolescence associated with more frequent marijuana use in early adolescence. RESULTS: Early adolescent marijuana use increased the risk in late adolescence of not graduating from high school; delinquency; having multiple sexual partners; not always using condoms; perceiving drugs as not harmful; having problems with cigarettes, alcohol, and marijuana; and having more friends who exhibit deviant behavior. These relations were maintained with controls for age, sex, ethnicity, and, when available, earlier psychosocial measures. CONCLUSIONS: Early adolescent marijuana use is related to later adolescent problems that limit the acquisition of skills necessary for employment and heighten the risks of contracting HIV and abusing legal and illegal substances. Hence, assessments of and treatments for adolescent marijuana use need to be incorporated in clinical practice. (+info)
Marijuana: medical implications.
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Over 50 percent of people will use marijuana sometime in their life. While intoxication lasts two to three hours, the active ingredient in marijuana, delta-9-tetrahydro-cannabinol, can accumulate in fatty tissues, including the brain and testes. Adverse effects from marijuana use include decreased coordination, epithelial damage to the lungs, increased risk of infection, cardiovascular effects and cognitive deficits. Unexplained behavior changes, altered social relationships and poor performance at school or work can signify a drug problem. Treatment requires a combination of education, social support, drug monitoring and attention to comorbid medical and psychiatric conditions. (+info)
Marijuana use and increased risk of squamous cell carcinoma of the head and neck.
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Marijuana is the most commonly used illegal drug in the United States. In some subcultures, it is widely perceived to be harmless. Although the carcinogenic properties of marijuana smoke are similar to those of tobacco, no epidemiological studies of the relationship between marijuana use and head and neck cancer have been published. The relationship between marijuana use and head and neck cancer was investigated by a case-control study of 173 previously untreated cases with pathologically confirmed diagnoses of squamous cell carcinoma of the head and neck and 176 cancer-free controls at Memorial Sloan-Kettering Cancer Center between 1992 and 1994. Epidemiological data were collected by using a structured questionnaire, which included history of tobacco smoking, alcohol use, and marijuana use. The associations between marijuana use and head and neck cancer were analyzed by Mantel-Haenszel methods and logistic regression models. Controlling for age, sex, race, education, alcohol consumption, pack-years of cigarette smoking, and passive smoking, the risk of squamous cell carcinoma of the head and neck was increased with marijuana use [odds ratio (OR) comparing ever with never users, 2.6; 95% confidence interval (CI), 1.1-6.6]. Dose-response relationships were observed for frequency of marijuana use/day (P for trend <0.05) and years of marijuana use (P for trend <0.05). These associations were stronger for subjects who were 55 years of age and younger (OR, 3.1; 95% CI, 1.0-9.7). Possible interaction effects of marijuana use were observed with cigarette smoking, mutagen sensitivity, and to a lesser extent, alcohol use. Our results suggest that marijuana use may increase the risk of head and neck cancer with a strong dose-response pattern. Our analysis indicated that marijuana use may interact with mutagen sensitivity and other risk factors to increase the risk of head and neck cancer. The results need to be interpreted with some caution in drawing causal inferences because of certain methodological limitations, especially with regard to interactions. (+info)
Substance abuse and the kidney.
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Substance abuse has been increasing steadily in the UK and some other countries. Recent evidence suggests more than 40% of young people have tried illicit drugs at some time. There are numerous medical consequences to recreational drug use, and a physician should always consider substance abuse in any unexplained illness. The renal complications of drug abuse are also becoming more frequent, and may encompass a spectrum of glomerular, interstitial and vascular diseases. Although some substances are directly nephrotoxic, a number of other mechanisms are also involved. These effects are often chronic and irreversible, but occasionally acute with possible recovery. The rapid growth of illicit drug use is clearly a major public health problem. We review the commonly used substances of abuse and their associations with renal disease. (+info)