The first study from Columbia University Mailman School of Public Health in New York found that you more than double your risk of an automobile accident if you use marijuana before driving a car. Professor Guohua Li and his colleagues went through information from nine previous studies in six different countries that tracked both marijuana and motor vehicle accidents. Some of the people in the study had used marijuana within an hour before driving, and others within a year or more. The study found that marijuana use affected driving skills for up to three to four hours, and the risk of a crash was 2.7 times higher among marijuana users then non-users.

Writing in the journal Epidemiologic Reviews, Dr. Li emphasized that the risk of an automobile crash in terms of marijuana use was related to the dose, the frequency of use, the strength of the drug, and how it was taken. Marijuana may interfere with muscular coordination and reaction times, he speculated.

Some critics say that the study does not actually prove that marijuana increases the risk of an automobile crash by two or three times.

"Most of these studies point to a very strong bad effect of marijuana and driving, but there are studies out there that actually go the other way," said Chuck Farmer, director of statistics at the Insurance Institute for Highway Safety.

The second study, this time from Radboud University Nijmegen in the Netherlands, found that smoking marijuana increases the risk of depression in young people who have genetic predispositions to that mental disorder. The research team analyzed data collected over five years from 428 families with two teenagers each, and found a strong association between marijuana use and increased depressive symptoms among those with the genetic predisposition. The Dutch researchers concluded that the teenagers were not using marijuana as a form of self medication, but that marijuana itself increased depressive symptoms in young people with that specific genotype.

"The effect is robust. It still remains, even if you take into account a series of other variables that cause the effect, such as smoking, alcohol use, upbringing, personality, and socio-economic status," the research team wrote in the journal Addiction Biology.

Sixteen states have legalized marijuana for medical uses only, although these new state policies are in conflict with a federal law that classifies marijuana as illegal to use for any reason.

Multiple surveys conducted all across the country were interpreted into a range of estimates. Youth from grades 7 to 12 were surveyed, but the most notable abuse of alcohol and cannabis was seen in those in Grade Twelve. Forty-one percent to 52 percent of 12th grade students reported having five or more alcoholic drinks on a single occasion within the last month. Twelve percent to 20 percent reported having two or more drinks within an hour before they got behind the steering wheel.

The statistics for the use of cannabis are only slightly lower, but still excessive and dangerous. In the last month, 15 percent to 27 percent of those surveyed used cannabis, and 3 percent to10 percent of those youth used it every day or close to every day. Fourteen percent to 21 percent reported using cannabis within the hour before they got behind the steering wheel – a higher percentage than those who used alcohol within an hour before driving.

The author of the study, Dr. Matthew Young, a Senior Research and Policy Analyst at the Canadian Centre on Substance Abuse, is concerned that some teens have a false sense of security that their driving is not impaired after they have used cannabis. This lack of knowledge could lead to more lives lost in automobile accidents. From 2000 to 2007, over half of drivers age 19 and younger who were fatally injured had drugs and/or alcohol in their system. Cannabis was one of the most common psychoactive substances found in these drivers.

Driver fatalities aren’t the only concern surrounding teen abuse of alcohol and marijuana. Dr. Young posed concerns that the abuse of these substances could lead to poor academic performance and a higher risk of mental health disorders.

Some interesting and encouraging information from the report: A large percentage of youth in grades 7 through 9 aren’t using drugs or alcohol at all. This information will hopefully influence teens in junior high, letting them know that their peers aren’t using these substances and there is no peer pressure to start substance abuse. Rather, by drinking and using cannabis at this age, they will be seen as the odd one.

This national picture of alcohol and cannabis use among Canada’s youth will help to serve the country in finding out the realities of alcohol and cannabis use among those in junior and senior high. This information can help map a plan to get knowledge and support to the age groups in need the most. Besides helping students and their families, the CSA and SDUS Working Group hopes that this report will help guide jurisdictional and national policy as well as initiatives in treatment, prevention and further research.

Denise Walker, co-director of the University of Washington’s Innovative Programs Research Group, said that marijuana is not a risk-free drug, and that although many people use marijuana without experiencing any problems, other people become addicted and want to stop but don’t know how to.

Walker is the lead author of a report demonstrating that brief, voluntary conversations with an adult led to a significant decrease (up to 20%) in marijuana use for teenagers who frequently used marijuana.

Walker, who is also a UW research assistant professor of social work, said that teens face greater risks from regular marijuana use compared wit adults, because adolescence is a developmental period for learning adult roles, and regular marijuana use can impede this development and academic performance, and also lays the foundation for other risky behaviors.

The researchers examined how a two-session approach called Teen Marijuana Check-Up could help reduce marijuana use in teens. Walker said that most people who need help aren’t getting it because they don’t think they need it, and that they tend to be ambivalent about their drug use.

Despite this, many teens are concerned about their drug use, even if they aren’t sharing their concerns with friends or family members. Walker added that offering teens an opportunity to weigh the pros and cons of marijuana use in a way that isn’t “shaming or blaming” is an effective approach that many teens will participate in voluntarily.

For the study, the researchers visited high-school classrooms and gave short presentations about the myths and facts regarding marijuana, common reasons why teens use the drug, and its behavioral and health consequences. The researchers told the students the study was to give feedback on the students’ marijuana use, not to treat them, and that students could volunteer to participate privately.

About 619 students volunteered and 310 smoked marijuana regularly. The participants, who attended public high schools in Seattle, had one-on-one meetings with health educators two separate times, with each meeting lasting 30-60 minutes over a two-week period. The health educators used one of two approaches: motivational interviewing, in which the student and educator discussed the student’s marijuana use and how it might be affecting the student’s life, or an educational approach in which a PowerPoint presentation described the health and behavioral effects of marijuana use through current marijuana research.

Those in the motivational interviewing group entered the study using marijuana 40 out of the previous 60 days. Three months after counseling began, their use had decreased by 20 percent, using 32 out of 60 days. After a year, they showed a 15 percent decrease, using 34 days out of 60.

Those in the educational group reported only an 8 percent decrease after three months of counseling, going from using 38 days out of the previous 60 days to 35 days out of 60. A year later, they reported using marijuana 34 of 60 days, an 11 percent overall decrease.

The researchers said these findings were encouraging, in that significant reductions in marijuana use resulted from brief meetings and were sustained over a year’s time.

Walker said the researchers hope the low-cost program could be used by drug and alcohol counselors in schools, because the program is designed to attract people who aren’t ready for full treatment such as marijuana rehab but are interested in talking with a professional about their concerns regarding marijuana use.

Source: Science Daily, Two Talks With Teens Leads to Less Marijuana Use for at Least a Year, Study Finds, June 27, 2011

A recent study examined the path experienced by children who experience maltreatment and how personality functioning develops as they grow to heighten their risk for cannabis abuse and dependence in adolescence. The longitudinal study investigated the association between childhood maltreatment with individual personality differences and the extent to which cannabis use could be explained by both (Oshri, et al., 2011).

The researchers examined the situations of 415 children, of which 259 had a history of maltreatment according to records from Child Protective Services. 156 of the children had no maltreatment records. The two groups of children were comparable in terms of socio-demographic factors.

The maltreatment was designated by severity and type and the researchers followed up with the participants three times from age 7 to age 15. During the first interview, the researchers measured ego control (the tendency to express emotional impulses) and ego resiliency (the capacity to change ego control to fit a situational need).

When the participants were between 10 and 12 years old, the researchers conducted the second interview, in which they measured externalizing and internalizing behaviors. Two camp counselors also evaluated the children using the Teacher Report Form. During the third interview, the participants were asked about their current cannabis use and dependence using a diagnostic designed for children.

The results of the analysis showed that childhood maltreatment was associated with problem behaviors at the second session and cannabis abuse and dependence at the third session. However, the results of the study may be limited by the use of peer and observer reports, which may not be accurate in assessing internal experiences and might contain observer biases. The sample also focused on high-risk economically disadvantaged youth, which may produce results differently than children in a broader sample representing the general population.

The results of the study give insight to the actual paths of children who experience maltreatment and then develop a problem with cannabis abuse and dependence. The diminished ability to control emotional impulses and inflexible emotional coping strategies put children at a higher risk for developing a problem with substance abuse.

The results of the study may prove to be very helpful in developing prevention programs to help children avoid initiation of cannabis use. In addition, the analysis may help in targeting children with a history of maltreatment for focused prevention efforts to reduce this population’s susceptibility to a cannabis addiction.

Teens apparently got the anti-smoking messages that cigarettes cause cancer and are addictive, but many believe that marijuana is safe to use because in some states, it can be prescribed as a medicine. Students told researchers that compared to cigarettes, they face less disapproval when they use marijuana, and it is easier to obtain and less risky.

Pot use is also up among eighth graders.

Over 20% of all high school seniors in the survey had used marijuana in the past 30 days.

The National Monitoring the Future survey revealed that more high school seniors are current marijuana smokers than cigarette smothers. Marijuana use rose slightly while cigarette smoking fell among 12th graders in 2010. The survey also found that binge drinking rates have dropped and the misuse of prescription drugs has stayed the same.

The survey also found that 21.4 percent of high school seniors reported smoking marijuana at least one time in the last month, compared to 19.2 percent who reported smoking cigarettes. Among seniors, 6.1 percent smoked marijuana daily, compared with 5.2 percent in 2009; daily use among 10th graders rose to 3.8 percent from 3.1 percent and to 1.2 percent from 1.0 percent among eighth graders.

Gil Kerlikowske, director of the White House Office of National Drug Control Policy, noted that the abundance of mixed messages about drug legalization – particularly marijuana – could be to blame for these increases. Parents and other adults who influence children need to work with administration to teach young people about the risks and harms associated with marijuana and other drug use.

While marijuana use is increasing, the good news is that the current rates are still lower than those that were reported in the same survey conducted in the 1970s and early 80s. In 1978, marijuana use peaked for this senior class with 10.7 percent reporting daily use.
 

A new study by the National Institute on Drug Abuse (NIDA) has found that middle and high school students across the U.S. are increasingly using illicit substances, with a particular rise in marijuana use. Based on the results of NIDA’s 2010 Monitoring the Future (MTF) survey, which assessed 46,482 students from both public and private schools, daily marijuana use was up across all grade levels measured (8th, 10th, and 12th grades). For example, past-year marijuana use rose among participants from all three grade levels in 2010. While the rate of teenage cigarette consumption has shown to plateau across all grade levels in recent years, the rate of twelfth graders’ past-month marijuana use, on the other hand, now exceeds their rate of cigarette use (21.4% vs. 19.2%). Teenagers’ daily marijuana use saw the most significant incline. In 2009, daily marijuana use was 1.0% for eighth graders, 2.8% for tenth graders, and 5.2% for twelfth graders; yet by 2010, these percentages increased to 1.2%, 3.3%, and 6.1% respectively.

The Office of National Drug Control Policy described this rise in teenage marijuana use as the result of increased publicity over the legalization of marijuana. Medical marijuana, now legalized in a dozen states and the District of Colombia, may send mixed messages to teenagers regarding the dangers of marijuana use. In a press release on Tuesday, NIDA Director Nora D. Volkow stated that more and more research is revealing that marijuana use can cause cognitive impairment to users—such as affected motor skills and learning and judgment abilities—particularly to teens whose brains are not yet fully developed. Also, studies have found that one in six adults who are currently addicted to marijuana began using the drug in their adolescence. However, the MTF survey showed that today’s teens perceive marijuana as less harmful than previous generations did. About 57.2% of tenth graders reported that marijuana smoking is harmful, down from 59.5% in 2009. Likewise, twelfth graders’ attitudes towards marijuana’s harmfulness dropped from 52.4% in 2009 to 46.8% in 2010. Eighth graders also showed a substantial decrease in their disapproval rating of marijuana use. With growing media emphasis over medical marijuana’s use to help treat conditions such as cancer, glaucoma, and HIV/AIDS, as well as the debate whether to legalize the seemingly ‘less harmful’ substance for adults, teenagers are now regarding the substance as a more acceptable drug of use.

Also on the rise is the illicit use of other drugs perceived as ‘harmless’ or legitimate, such as prescription medications and MDMA—otherwise known as ecstasy. In light of teenagers’ increased use of marijuana, eighth grade participants also admitted to having a higher rate of illicit drug use, rising from 14.5% in 2009 to 16% in 2010. Compared to 2009, almost twice as many eighth graders were found to have used ecstasy within the past year (1.3% vs. 2.4%). Tenth graders displayed a similarly rising trend in ecstasy use, from 3.7% in 2009 to 4.7% in 2010. The rate of teenagers’ nonmedical use of prescription drugs, too, remained high in this year’s survey. While Vicodin abuse was down from 9.7% to 8% among high school seniors, the survey found OxyContin abuse by seniors remained steady at 5.1%. Out of the ten most abused prescription drugs reported by teenagers, six of them were either prescribed or received over-the-counter. The majority of teens admitted to receiving, purchasing, or stealing these prescriptions drugs from a friend or family member.

Teenagers’ rising acceptance, perceived harmlessness, and accessibility of marijuana are three strong predictors of future abuse. In midst of the political debate over adult use of medical or legalized marijuana, NIDA emphasizes the need for parents and educators to intervene and prevent risky behavior among teens, including the use of marijuana and other substances. Not only can regular marijuana use stunt their cognitive growth during their formative years, but it also poses a risk for addiction and long-term impairment.

NIDA’s annual MTF survey was conducted by researchers at the University of Michigan, Ann Arbor.

Source: USA Today, Rita Rubin, U.S.: More Teens Smoke Marijuana Than Cigarettes, December 15, 2010

Previous research has found that marijuana users have trouble changing behavioral responses in the context of certain situations, which is known as cognitive flexibility. The current study, led by Staci Gruber, PhD, at McLean Hospital and Harvard Medical School, looked at participants’ performance on a test of cognitive flexibility called the Wisconsin Card Sorting Task.

Participants were shown four cards that differ in color, symbol, and value. Based on the rules they pick up on from displayed cards, they had to sort a deck of cards. They weren’t told what the rules are; instead they were told whether their sorting was correct or incorrect. The rules were changed without warning during the test, and the participants had to respond accordingly. The way in which they responded is a strong indicator of cognitive flexibility.

The study also found that regular marijuana users made repeated errors, even after being told they were answering incorrectly. Heavy users also had more trouble maintaining a set of rules, which suggests that they had trouble focusing on the task. Those who started using marijuana before age 16 and those who used the most marijuana were the most impaired.

Gruber said that the study adds to the growing evidence that marijuana directly affects cognitive function, and that both the age at which a person starts using marijuana and the amount of marijuana used can significantly affect cognition. With the prevalence of marijuana, the study highlights the importance of curbing marijuana use, especially among adolescents.

Source: Science Daily, Human Study Shows Greater Cognitive Deficits in Marijuana Users Who Start Young, November 17, 2010

The survey, conducted by the Indiana Prevention Resource Center at Indiana University with funding provided by the Indiana Family and Social Services Administration’s Division of Mental Health and Addiction, questioned 169,059 students from 523 public and private schools.

Ruth Gassman, director of the Indiana Prevention Resource Center, said that the number of adolescents using marijuana has been increasing since 2008, which could suggest a lack of concern about the use of the drug. She added that marijuana can impair learning and concentration, reduce short-term memory, and increase heart rate.

This year, 1.5 percent of sixth graders reported using marijuana, which is up from 1.3 percent in 2008. Among ninth graders, the numbers went from 10.4 percent to 12.7 percent. For twelfth graders, the numbers increased from 16.2 percent to 19.2 percent.

The survey also found that smoking decreased by sixth through twelfth graders since 2009. Among twelfth graders, the numbers decreased by 3.2 percent. Gassman said this shows that smoking prevention efforts Indiana have been working.

However, there was an upward trend in the use of tobacco pipes. Monthly use increased from 2.5 percent in 2006 to 5.2 percent in 2010, and lifetime use increased from 6.0 percent in 2006 to 11.1 percent in 2010.

The survey also found that perception of easy access to alcohol, cigarettes, and marijuana was associated with an increase in use. Gassman said that family members and adults can play an important role in preventing adolescents from accessing these substances. The most important way to prevent kids from using these drugs is for adults to not use them, and to make sure that alcohol, cigarettes, marijuana, and other drugs aren’t kept in the house.

Source: Indiana University, Youth drug use in Indiana: Annual survey finds increasing use of marijuana, tobacco in pipes, September 8, 2010

The survey, released by the Center for Medicine in the Public Interest, comes as the Food and Drug Administration examines whether over-the-counter cough syrups and other medications containing dextromethorphan (DXM) should be placed behind the counter or available by prescription only. Many teens abuse DXM-containing products to get high, which can be very dangerous, especially when mixed with alcohol.

The participants of the survey said they thought educating teens about the negative consequences of abusing DXM products was better than making the products harder to access, but the FDA could make more than 100 over-the-counter medicines with DXM availably only through a doctor’s prescription or placed behind the counter at pharmacies, requiring assistance to make a purchase.

Seventy percent of high school teachers and fifty-one percent of police officers said alcohol was a big threat to teens, whereas sixty-nine percent of police officers and fifty-one percent of teachers said marijuana was the biggest problem. Prescription drugs followed, with 27 percent of police officers and 15 percent of teachers identifying prescription pills as a threat.

Methamphetamine was viewed as a problem by 28 percent of police officers and 9 percent of teachers; and cocaine was seen as problematic by 22 percent of police officers and 8 percent of teachers. Surprisingly, only 3 percent of police officers and 6 percent of teachers listed cigarettes and tobacco as being very harmful to teens. Only one percent of teachers listed over-the-counter cough and cold medications.

Source: Center for Medicine in the Public Interest, Survey of Police and Teachers: Alcohol and Marijuana Most Serious Substance Abuse Facing Teens, September 9, 2010