Marijuana Abuse
Facts about Marijuana Use
Scientists at McLean Hospital/Harvard Medical School observed that male volunteers who drank alcohol (vodka mixed with orange juice) prior to smoking marijuana detected the effects of marijuana more quickly, reported more episodes of euphoria, and had higher levels of THC in their blood than did subjects who smoked marihuana without first ingesting alcohol.
The investigators concluded that alcohol might increase the absorption of THC, the active ingredient of marijuana, into the body, resulting in a higher high than is experienced when using marijuana alone.
What it means: Marijuana and alcohol are often used together, but little is known about why they are combined. The results of this experiment suggest that these two drugs are used to maximize the desired effects of the drug experience and so may explain the popularity of this combination.
The study was published in Volume (issue): 64 (2) 2001 of the journal Drug and Alcohol Dependence by lead investigator Dr. Scott E. Lukas.
Researchers at the McLean Hospital/Harvard Medical School have found that heavy, long-term marijuana use produces memory impairment for days or even weeks after users stop smoking.
To ascertain the effects of marijuana use on memory and other cognitive skills, the Harvard research team recruited 180 individuals between the ages of 30 and 55. About one-third of the subjects were current heavy users who had smoked marijuana at least 5,000 times in their lives (equivalent to using the drug at least once a week for 13 or more years) and who were smoking daily at the time they entered the study; another third were former heavy users. Individuals inthe control group had used marijuana at least once but fewer than 50 times in their lives. All of the subjects were asked to abstain from marijuana for 28 days, and their drug abstinence was confirmed by urine samples. They were administered a battery of tests to assess general intellectual function, abstraction ability, attention span, verbal fluency, and ability to learn and to recall new verbal and visuospatial information just before and then on the 1st, 7th, and 28th days ofabstinence. At days 0, 1, and 7,
current heavy users of marijuana scored significantly lower than the control subjects on recall of word lists, but by day 28, there were virtually no differences among the groups on any of the tests.
Cognitive deficits were detectable at least 7 days after heavy marijuana use, but these changes appeared to dissipate within a few weeks, after THC (tetrahydrocannabinol), the active ingredient of marijuana, and its metabolites have cleared the body.
What it means: This study clearly points out that marijuana is not a benign substance. By impairing memory and other cognitive functions, smoking marijuana can negatively affect academic achievement and other life skills.
Lead investigator Dr. Harrison G. Pope, Jr. published the study in the October 2001 issue of Archives of General Psychiatry.
Researchers at the University of Chicago, in experiments with mice, have found that prenatal exposure to methamphetamine increases response to the toxic effects of the drug in adult males. Some effects of prenatal methamphetamine exposure were observed in female offspring, but were much less than those seen in the males.
The investigators say these findings may raise concerns for male methamphetamine abusers whose mothers used the drug while pregnant. The neurotoxic risk from using methamphetamine as adults may be greater for men who were exposed prenatally. Methamphetamine toxicity is characterized by persistent decreases in the levels
of dopamine and serotonin in certain brain regions. It is known that in humans, dopamine deficits are associated with symptoms of Parkinson's disease.
What it means: This finding, coupled with the increasing use of club drugs, such as methamphetamine, by women of childbearing age, makes this issue a potential public health concern.
The researchers, led by Dr. Alfred Heller, published their findings in the August 2001 issue of the Journal of Pharmacology and Experimental Therapeutics.
Surveys of more than 7,000 individuals questioned periodically from middle school through their mid-30’s about their beliefs concerning the risks from smoking cigarettes and the value they place on health reveal that these attitudes change with age.
A research team from Arizona State University and Indiana University drew participants for the study from a large, Midwestern community. At the most recent assessment, 26 percent smoked cigarettes. The researchers found that:
Between the ages of 11 and 14, the perception that smoking would harm one’s own health decreased. However, between the ages of 15 and 18 and continuing to age 24, there was an increased belief that smoking can be harmful to one’s personal health.
Throughout adolescence and young adulthood, there was a small but statistically significant increase in the belief that cigarette smoking is harmful to people’s health in general.
Between the ages of 15 and 18, the value that adolescents placed on health decreased. However, the value placed on health increased starting at age 19 and continued to increase up to age 29.
Between ages 11 and 14, belief in the positive psychological consequences of smoking increased; however this trend reversed between ages 15 and 18.
Between 11 and 14, the belief that cigarettes are addicting decreased, but between the ages of 15 and 18 and between ages 19 and 24, both smokers and nonsmokers increased their belief that cigarettes are addicting.
Across all age groups, those who smoked were significantly less likely to believe that smoking is harmful to either health in general or to their own personal health, and smokers placed significantly less value on health than did nonsmokers.
What it means: Smoking interventions aimed at adolescents must counter the perception among middle school students that cigarette smoking does not pose a risk of addiction or a risk to one’s own health, and must counter the declining values placed on health by high school students.
The research team led by Drs. Laurie Chassin and Clark Presson from Arizona State University and Dr. Steven J. Sherman from Indiana University published the study in the September, 2001 issue of Health Psychology.
Source: NIDA NewsScan - www.drugabuse.gov
|
|
|
