Archive for August, 2012

Statistics

To find research statistics and charts on alcohol abuse, alcohol dependence, consumption, morbidity, cirrhosis, underage drinking and alcohol-related traffic fatalities, go to this page.

August 31st, 2012  in Uncategorized No Comments »

Teen pot use leaves lasting mental deficits

The persistent, dependent use of marijuana before age 18 has been shown to cause lasting harm to a person’s intelligence, attention and memory, according to an international research team.

Among a long-range study cohort of more than 1,000 New Zealanders, individuals who started using cannabis in adolescence and used it for years afterward showed an average decline in IQ of 8 points when their age 13 and age 38 IQ tests were compared. Quitting pot did not appear to reverse the loss either, said lead researcher Madeline Meier, a post-doctoral researcher at Duke University. The results appear online Aug. 27 in PNAS.

Brain Age a Factor in Marijuana Use

The key variable in this is the age of onset for marijuana use and the brain’s development, Meier said. Study subjects who didn’t take up pot until they were adults with fully-formed brains did not show similar mental declines. Before age 18, however, the brain is still being organized and remodeled to become more efficient, she said, and may be more vulnerable to damage from drugs.

“Marijuana is not harmless, particularly for adolescents,” said Meier, who produced this finding from the long term Dunedin Multidisciplinary Health and Development Study. The study has followed a group of 1,037 children born in 1972-73 in Dunedin, New Zealand from birth to age 38 and is led by Terrie Moffitt and Avshalom Caspi, psychologists who hold dual appointments at Duke and the Institute of Psychiatry at King’s College London.

Psychological Tests Given

About 5 percent of the study group were considered marijuana-dependent, or were using more than once a week before age 18. A dependent user is one who keeps using despite significant health, social or family problems.

At age 38, all of the study participants were given a battery of psychological tests to assess memory, processing speed, reasoning and visual processing. The people who used pot persistently as teens scored significantly worse on most of the tests. Friends and relatives routinely interviewed as part of the study were more likely to report that the persistent cannabis users had attention and memory problems such as losing focus and forgetting to do tasks.

The decline in IQ among persistent cannabis users could not be explained by alcohol or other drug use or by having less education, Moffitt said.

8 Points Is Huge

While 8 IQ points may not sound like a lot on a scale where 100 is the mean, a loss from an IQ of 100 to 92 represents a drop from being in the 50th percentile to being in the 29th, Meier said. Higher IQ correlates with higher education and income, better health and a longer life, she said. “Somebody who loses 8 IQ points as an adolescent may be disadvantaged compared to their same-age peers for years to come,” Meier said.

Laurence Steinberg, a Temple University psychologist who was not involved in the research, said this study is among the first to distinguish between cognitive problems the person might have had before taking up marijuana, and those that were apparently caused by the drug. This is consistent with what has been found in animal studies, Steinberg added, but it has been difficult to measure in humans.

Early Use Causes Deficits

Animal studies involving nicotine, alcohol and cocaine have shown that chronic exposures before the brain is fully developed can lead to more dependence and long-term changes in the brain. “This study points to adolescence as a time of heightened vulnerability,” Steinberg said. “The findings are pretty clear that it is not simply chronic use that causes deficits, but chronic use with adolescent onset.”

What isn’t possible to know from this study is what a safer age for persistent use might be, or what dosage level causes the damage, Meier said. After many years of decline among US teens, daily marijuana use has been seen to increase slightly in the last few years, she added. Last year, for the first time, US teens were more likely to be smoking pot than tobacco.

“The simple message is that substance use is not healthy for kids,” Avshalom Caspi said via email from London. “That’s true for tobacco, alcohol, and apparently for cannabis.”

August 30th, 2012  in Illegal Drugs No Comments »

Early Alcohol Use Spells Trouble for College Students

An early age at first drink (AFD) has been linked to later alcohol-related problems, which is one of the reasons behind the legal drinking age of 21 in the U.S. It is unclear, however, if increased risk is primarily due to initiation of any drinking, or initiation of heavier drinking.

A comparison of the influence of these potential risk factors among college undergraduates found that both an early AFD as well as a quick progression from the first drink to drinking to intoxication independently predicted later problems.

Results will be published in the journal Alcoholism: Clinical & Experimental Research and are currently available at Early View.

Negative Alcohol-Related Outcomes

“Many studies have found relationships between an early AFD and a range of negative alcohol-related outcomes later in life, including the development of alcohol use disorders, legal problems like DUI, and health problems like cirrhosis of the liver,” said Meghan Rabbitt Morean, a postdoctoral fellow in the department of psychiatry at Yale University School of Medicine and corresponding author for the study. “There is also evidence that beginning to drink at an early age is associated with more immediate problems, such as compromised brain development and liver damage during adolescence, risky sexual behaviors, poor performance in school, and use of other substances like marijuana and cocaine.”

Harriet de Wit, a professor in the department of psychiatry and behavioral neuroscience at The University of Chicago, concurred. “While it is commonly believed that the earlier a person begins drinking alcohol, the more likely it is that he or she will develop problems with drinking, many factors potentially contribute to this relationship, and these factors can only be disentangled with systematic, longitudinal research.”

Drinking at an Early Age

While an early AFD is associated with many negative consequences, it is not clear that it directly causes heavy drinking or other negative outcomes, Morean added. “Prior research on early intoxication … suggested to us that making a distinction between the age at which an individual first has any alcohol and the age at which an individual first drinks to intoxication may have important implications for understanding the relative risk associated with starting to drink at an early age,” she said.

Morean and her colleagues examined 1,160 freshman (766 females, 394 males) using data gathered from bi-annual assessments from the summer following high-school senior year through the fall of the fourth year of college (four years in total). Participants self-reported their age of drinking onset and age of first self-defined intoxication, as well as frequency of heavy drinking and alcohol-related problems. Analyses looked at the effects of AFD and the time from first use to first intoxication as predictors of heavy drinking and problems across the four years from high school through college.

Greater Risk for Heavy Drinking

“As expected, beginning to use alcohol at an earlier age was associated with heavier drinking and the experience of more negative consequences during senior year of college,” said Morean. “Quickly progressing from first alcohol use to drinking to intoxication was also an important predictor of heavy drinking and the experience of alcohol related problems during senior year of college. For example, an adolescent who consumed his first drink at age 15 was at greater risk for heavy drinking and problems than an adolescent who took his first drink at age 17. Further, an adolescent who took his first drink at age 15 and also drank to intoxication at age 15 was at greater risk for heavy drinking and problems than an adolescent who had his first drink at age 15 and did not drink to the point of intoxication until he was 17.”

“The authors also found that impulsive personality and family history of alcoholism were related to age of first drink and future problems,” added de Wit.

Preventing Alcohol Use

Both Morean and de Wit agreed that early drinking should be delayed, but if it occurs, these youth should be counseled to avoid drinking to intoxication.

“The best way to prevent heavy drinking and the experience of alcohol-related problems is to prevent alcohol use,” said Morean. “Therefore, our first recommendation would be to delay the onset of any alcohol use as long as possible. However, despite valiant prevention efforts, the average American adolescent has his or her first alcoholic drink between the ages of 14 and 15 years.”

“Furthermore,” said de Wit, “it is unlikely that education will discourage high school and college students from drinking at all. However, education may help to make them aware of the potential for developing future problems, and modulate their drinking accordingly.”

Speak to Your Children

“It is important to speak to children and adolescents openly about the dangers of heavy drinking and provide them with correct information, for example, ‘how many drinks does an average male/female need to drink to exceed the legal level for intoxication?,'” said Morean. “It is also extremely important to remember that heavy drinking during adolescence and early adulthood is not confined to college campuses. Most adolescents begin drinking during high school, a significant portion of whom begin drinking heavily. To help address this, we suggest that new alcohol prevention and intervention efforts targeting high school students be developed with the goal of delaying onset of heavy drinking among those at increased risk due to an early onset of drinking.”

August 16th, 2012  in Alcohol No Comments »

Brain activity may predict teens’ heavy drinking

Heavy drinking is known to affect teenagers’ developing brains, but certain patterns of brain activity may also help predict which kids are at risk of becoming problem drinkers, according to a study in the Journal of Studies on Alcohol and Drugs.

Using special MRI scans, researchers looked at 40 12- to 16-year-olds who had not started drinking yet, then followed them for about 3 years and scanned them again. Half of the teens started to drink alcohol fairly heavily during this interval.

The investigators found that kids who had initially showed less activation in certain brain areas were at greater risk for becoming heavy drinkers in the next three years.

Drinking Affects Brain Activity

Then once the teens started drinking, their brain activity looked like the heavy drinkers’ in the other studies – that is, their brains showed more activity as they tried to perform memory tests. This pattern of heavy drinking typically included episodes of having four or more drinks on an occasion for females and five or more drinks for males.

“That’s the opposite of what you’d expect, because their brains should be getting more efficient as they get older,” said lead researcher Lindsay M. Squeglia, Ph.D., of the University of California, San Diego.

The findings add to evidence that heavy drinking has consequences for teenagers’ developing brains. But they also add a new layer: there may be brain activity patterns that predict which kids are at increased risk for heavy drinking.

“It’s interesting because it suggests there might be some pre-existing vulnerability,” Squeglia said.

Clues to Problem Drinking

That doesn’t mean teenagers are going to start having MRI scans of their brains to see which ones might start drinking. But the findings do give clues into the biological origins of kids’ problem drinking.

These findings also reinforce the message that heavy drinking may affect young people’s brains right at the time when they need to be working efficiently.

“You’re learning to drive, you’re getting ready for college. This is a really important time of your life for cognitive development,” Squeglia said. She noted that all of the study participants were healthy, well-functioning kids. It’s possible that teens with certain disorders — like depression or ADHD — might show greater effects from heavy drinking.

August 10th, 2012  in Alcohol No Comments »

Childhood defiance linked to drug dependence

Children who exhibit oppositional behavior run the risk of becoming addicted to nicotine, cannabis and cocaine whilst Inattention symptoms represent a specific additional risk of nicotine addiction. Nevertheless, hyperactivity in itself does not seem to be associated with any specific risk of substance abuse or dependence.

This is what researchers at the Sainte-Justine University Hospital Center’s (UHC) Research Center and the University of Montreal concluded following a 15-year population-based study published in Molecular Psychiatry.

Evaluated by Their Mothers

In order to delineate the roles played by inattention, hyperactivity, opposition, anxiety and adversity, the behavior of 1,803 children between 6 and 12 years of age were evaluated annually by their mothers and teachers. Over half the participants were females. The study revealed that by the age of 21, 13.4% were either abusing or addicted to alcohol, 9.1% to cannabis, and 2.0% to cocaine. Tobacco addiction was a problem for 30.7 % of the participants.

The link between attention deficit hyperactivity disorder (ADHD) in childhood and substance abuse in adulthood was already known. However, very few studies have been undertaken into the particular and respective roles of behavioural symptoms such as opposition that are often concomitant with ADHD (without being part of the disorder), attention deficit and hyperactivity. Furthermore, at least as many girls as boys were sampled in order to assess the potential impact of gender on the findings.

Cannabis and Cocaine Use

“By taking into account the unique effect of inattention and hyperactivity, which had seldom been considered separately before, we came to realize that the link between ADHD symptoms in childhood and substance abuse in adulthood was overestimated and hyperactivity in itself did not seem, in this study, to predispose for future substance abuse,” observed Dr. Jean-Baptiste Pingault, a postdoctoral fellow and first author of the study conducted under the supervision of Drs Sylvana Côté and Richard E. Tremblay, both researchers at the Sainte-Justine UHC’s Research Center and professors at the University of Montreal.

“We have rather observed strong oppositional behaviors to be associated with cannabis and cocaine abuse. In ADHD symptoms, only inattention is closely correlated with nicotine addiction,” he continued. As for the impact of gender on findings, the study reveals opposition and inattention play a largely identical role in girls and boys. However, within the context of the study, it was established that boys consumed more cannabis and alcohol, while girls smoked more cigarettes.

Opposition and Drug Addiction

The strongest behavioral predictor of substance abuse lies in frequent oppositional behavior in childhood, which can be recognized through traits such as irritability, being quick to “fly off the handle,” disobedience, refusal to share materials with others to carry out a task, blaming others and being inconsiderate of others. In fact, in strongly oppositional children, the risk of tobacco abuse, once other factors were taken into account, was 1.4 times higher than in children who exhibited little oppositional behavior.

The risk is 2.1 times higher for cannabis abuse and 2.9 times higher for cocaine abuse. It should be noted that the mothers’ evaluations provided further essential information in relation to the teachers’ evaluations. In fact, some children who were declared highly oppositional by their mothers, but not at all by their teachers, also ran a higher risk of substance abuse and addiction.

Inattention and Smoking

The other important correlation established by the study was the link between inattention and smoking. Very inattentive children had a 1.7-fold increased risk of becoming addicted to tobacco. The degree of inattention even reveals the intensity of future nicotine addiction. The link supported the hypothesis that inattentive people would use tobacco as a “treatment” to help them concentrate.

“If other studies can establish a chemical relation of cause and effect between ADHD symptoms and smoking, we could suppose that treating inattention symptoms would make it easier to quit smoking. Until this is demonstrated, our study’s findings nonetheless suggest that the prevention or treatment of inattention and opposition symptoms in children could reduce the risk of smoking and drug abuse in adulthood,” concluded Dr. Pingault.

August 6th, 2012  in Substance Abuse No Comments »