First Do No Harm – “Why Take a Chance?”
Why are people shocked about this?
Are they just hypocrites, or do you also find this inappropriate?
What policy does the “Medical Marijuana” industry propose to discourage this type of abuse?
Teenagers who regularly smoke cannabis are putting themselves at risk of permanently damaging their intelligence, according to a landmark study.
Starting smoking cannabis during one’s teens can have permanent effects on the brain, found researchers.
July 27, 2012
Researchers found persistent users of the drug, who started smoking it at school, had lower IQ scores as adults.
They were also significantly more likely to have attention and memory problems in later life, than their peers who abstained.
Furthermore, those who started as teenagers and used it heavily, but quit as adults, did not regain their full mental powers, found academics at King’s College London and Duke University in the US.
They looked at data from over 1,000 people from Dunedin in New Zealand, who have been followed through their lives since being born in 1972 or 1973.
Participants were asked about cannabis usage when they were 18, 21, 26, 32 and 38. Their IQ was tested at 13 and 38. In addition, each nominated a close friend or family member, who was asked about attention and memory problems.
About one in 20 admitted to starting cannabis use before the age of 18, while a further one in 10 took up the habit in the early or mid 20s.
the study, published in the journal Proceedings of the National Academy of Sciences, said “persistent users” who started as teenagers suffered a drop of eight IQ points at the age of 38, compared to when they were 13.Professor Terrie Moffitt, of KCL’s Institute of Psychiatry, who contributed to
Persistent users meant those who used it during at least three of the ages from 18 to 38, and who said at each occasion they were smoking it on at least four days a week.
She said: “Adolescent-onset cannabis users, but not adult-onset cannabis users, showed marked IQ decline from childhood to adulthood.
“For example, individuals who started using cannabis in adolescence and used it for years thereafter showed an average eight-point IQ decline.
“Quitting or reducing cannabis use did not appear to fully restore intellectual functioning among adolescent-onset former persistent cannabis users,” she said.
Although eight points did not sound much, it was not trivial, she warned.
It meant that an average person dropped far down the intelligence rankings, so that instead of 50 per cent of the population being more intelligent than them, 71 per cent were.
“Research has shown that IQ is a strong determinant of a person’s access to a college education, their lifelong total income, their access to a good job, their performance on the job, their tendency to develop heart disease, Alzheimer’s disease, and even early death,” she said.
“Individuals who lose eight IQ points in their teens and 20s may be disadvantaged, relative to their same-age peers, in most of the important aspects of life and for years to come.”
The cognitive abilities of the 10 per cent of people who started in their 20s – who could loosely be classed as college smokers – also suffered while they were still smoking.
However, if they gave up at least a year before their IQ test at 38, their intelligence recovered, suggesting their brains were more resilient and bounced back.
Prof Moffitt said adolescent brains appeared “more vulnerable to damage and disruption” from cannabis than those of fully mature adults.
Reliable figures on cannabis usage among today’s British teens and twentysomethings are hard to come by.
But Prof Moffitt said there was growing concern in the US that cannabis was increasingly being seen as a safe alternative to tobacco.
“This is the first year that more secondary school students in the US are using cannabis than tobacco, according to the Monitoring the Future project at the University of Michigan,” she noted.
“Fewer now think cannabis is damaging than tobacco. But cannabis is harmful for the very young.”
Answer: Yes. Marijuana has … up to 5 times as much tar as tobacco.
Marijuana has recently (June, 2009) been added to the Proposition 65 list of chemicals known to the state of Calfornia to cause cancer. Second-hand marijuana smoke contains 50% to 70% more harmful chemicals than tobacco smoke. See http://oehha.ca.gov/Prop65/docs_state/mjcrnr061909.html
Children can be affected differently than adults. While large doses of THC [tetrahydrocannabinol] act as a CNS [central-nervous system] depressant, lower levels of THC can act as a stimulant, so kids can go around talking incessantly when exposed to a parent’s smoke. Teenagers’ mood swings can get worse, and some kids become forgetful, angry, or violent after having been in a smoke-filled party room.
Doctors advise pregnant women not to use any drugs because they could harm the growing fetus. … Studies in children born to mothers who used marijuana have shown increased behavioral problems during infancy and preschool years. In school, these children are more likely to have problems with decision-making, memory, and the ability to remain attentive. Researchers are not certain whether health problems that may be caused by early exposure to marijuana will remain as the child grows into adulthood. However, since some parts of the brain continue to develop throughout adolescence, it is also possible that certain kinds of problems may appear as the child matures.
Differential Cognitive Functioning in 9-12 Years Olds Relative to Prenatal Cigarette and Marijuana Exposure
In an examination of cognitive performance of 131 (one-hundred-thirty-one), 9-12 year-old children participating in a Carleton University longitudinal study since birth, discriminant function analysis indicated a dose-dependent association between higher prenatal cigarette exposure in utero and lower performance on global intelligence test scores, with the verbal subtests of the intelligence test discriminating maximally among levels of in utero exposure. In contrast, prenatal marijuana exposure was not associated with global intelligence or the verbal subtests, but rather was negatively related to executive function tasks that require impulse control and visual analysis/hypothesis testing, and with a number of the intelligence subtests requiring these same abilities. The cigarette results extend observations made in this sample and others at earlier ages. The marijuana findings, combined with results observed at earlier ages, lead the authors to suggest that in utero exposure to marijuana may have a negative impact on aspects of neurocognitive competence that fall under the domain of executive function. Fried, P.A., Watkinson, B.M. and Gray, R. Neurotoxicology and Teratology, 20 (3), pp. 293-306, 1998.
Neurocognitive function in clinically stable men with bipolar I disorder or schizophrenia and normal control subjects
Patients with bipolar disorder and schizophrenia have been shown to have neurocognitive deficits when compared with control subjects. The degree and pattern of impairment between psychiatric groups have rarely been compared, especially when subjects are psychiatrically stable. … Subjects with bipolar disorder were impaired in two specific domains (verbal memory and executive function). Furthermore, within the bipolar group there was a subset with relatively normal executive functioning and a subset with significant impairment. Possible reasons for the persistence of these neurocognitive deficits in some subjects with bipolar disorder during periods of euthymia are reviewed. – Biological Psychiatry, Volume 56, Issue 8, Pages 560-569 (15 October 2004).
† High doses of marijuana can produce an acute psychotic reaction; in addition, use of the drug may trigger the onset or relapse of schizophrenia in vulnerable individuals. … Marijuana intoxication can cause distorted perceptions, impaired coordination, difficulty in thinking and problem solving, and problems with learning and memory. … Marijuana has the potential to cause problems in daily life or make a person’s existing problems worse. In one study, heavy marijuana abusers reported that the drug impaired several important measures of life achievement including physical and mental health, cognitive abilities, social life, and career status.‡A number of studies have shown an association between chronic marijuana use and increased rates of anxiety, depression, suicidal ideation, and schizophrenia. Some of these studies have shown age at first use to be a factor, where early use is a marker of vulnerability to later problems. However, at this time, it is not clear whether marijuana use causes mental problems, exacerbates them, or is used in attempt to self-medicate symptoms already in existence. Chronic marijuana use, especially in a very young person, may also be a marker of risk for mental illnesses, including addiction, stemming from genetic or environmental vulnerabilities, such as early exposure to stress or violence. At the present time, the strongest evidence links marijuana use and schizophrenia and/or related disorders.
A new study from the University of Southern California (USC) has found a link between recreational marijuana use and an increased risk of developing subtypes of testicular cancer that tend to carry a somewhat worse prognosis. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the findings suggest that the potential cancer-causing effects of marijuana on testicular cells should be considered not only in personal decisions regarding recreational drug use, but also when marijuana and its derivatives are used for therapeutic purposes in young male patients.
Testicular cancer is the most common cancer diagnosed in young men ages 15 to 45 years. The malignancy is becoming more common, and researchers suspect this is due to increasing exposure to unrecognized environmental causes.
To see if recreational drug use might play a role, Victoria Cortessis, MSPH, PhD, assistant professor of preventive medicine at the Keck School of Medicine of USC in Los Angeles, and her colleagues looked at the self-reported history of recreational drug use in 163 young men diagnosed with testicular cancer and compared it with that of 292 healthy men of the same age and race/ethnicity.
The investigators found that men with a history of using marijuana were twice as likely to have subtypes of testicular cancer called non-seminoma and mixed germ cell tumors. These tumors usually occur in younger men and carry a somewhat worse prognosis than the seminoma subtype. The study’s findings confirm those from two previous reports in CANCER on a potential link between marijuana use and testicular cancer.
“We do not know what marijuana triggers in the testis that may lead to carcinogenesis, although we speculate that it may be acting through the endocannabinoid system—the cellular network that responds to the active ingredient in marijuana—since this system has been shown to be important in the formation of sperm,” said Cortessis.
The researchers also discovered that men with a history of using cocaine had a reduced risk of both subtypes of testicular cancer. This finding suggests that men with testicular cancer are not simply more willing to report a history of using recreational drugs. While it is unknown how cocaine may influence testicular cancer risk, the authors suspect that the drug may kill sperm-producing germ cells since it has this effect on experimental animals.
“If this is correct, then ‘prevention’ would come at a high price,” Cortessis said. “Although germ cells can not develop cancer if they are first destroyed, fertility would also be impaired. Since this is the first study in which an association between cocaine use and lower testis cancer risk is noted, additional epidemiological studies are needed to validate the results.”
The study was supported by grants from the National Cancer Institute (CA17054, CA136967, and CA102042).