Archive for September, 2012

Shape of glass affects drinking rate

Dr Angela Attwood and colleagues from Bristol’s School of Experimental Psychology recruited 160 social drinkers aged 18-40 with no history of alcoholism to attend two experimental sessions. At one session they were asked to drink either lager or a non-alcoholic soft drink from either a straight-sided glass or a curved ‘beer flute’.

The participants were almost twice as slow when drinking alcohol from the straight-sided glass compared to the curved glass. There was no difference in drinking rates from the glasses when the drink was non-alcoholic.

More Difficult to Judge Halfway Mark

The researchers suggest that the reason for this may be because it is more difficult to accurately judge the halfway point of shaped glasses. As a result, drinkers are less able to gauge how much they have consumed.

In order to test this, participants attended another session in which they completed a computer task that presented numerous pictures of the two glasses containing varying volumes of liquid. By asking participants to judge whether the glass was more or less than half full, the researchers were able to show that there was greater error in accurately judging the halfway point of the curved glass.

Speed Influences Intoxication Level

Importantly, the degree of this error seemed to be associated with the speed of drinking. That is, the participants who tended to show the greatest error in their halfway judgments tended to show the greatest changes in drinking rate.

The speed at which an alcoholic beverage is drunk will influence the level of intoxication experienced, and also the number of drinks consumed in a single drinking session. Therefore, slowing drinking rates is likely to have positive impact for the individual and also at a population level.

Pacing Your Drinking

Dr Attwood said: “Due to the personal and societal harms associated with heavy bouts of drinking, there has been a lot of recent interest in alcohol control strategies. While many people drink alcohol responsibly, it is not difficult to have ‘one too many’ and become intoxicated. Because of the negative effects alcohol has on decision making and control of behaviour, this opens us up to a number of risks.

“People often talk of ‘pacing themselves’ when drinking alcohol as a means of controlling levels of drunkenness, and I think the important point to take from our research is that the ability to pace effectively may be compromised when drinking from certain types of glasses.”

September 11th, 2012  in Alcohol No Comments »

Teen marijuana use can lower I.Q.

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.

Early Onset the Key

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.

Tested at Age 38

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.

8 IQ Points Is Huge

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.

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.

Long-Term Changes in the Brain

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.”

September 4th, 2012  in Illegal Drugs No Comments »

Marijuana poses dangers in first weeks of pregnancy

Marijuana is up to 20 times more potent than it was 40 years ago and most pregnant women who use the drug are totally unaware that it could harm their unborn child before they even know they are pregnant.

Writing in the journal Drug Testing and Analysis, American researcher’s state the argument that marijuana is a harmless drug is no longer valid due to the emergence of ‘high potency’ marijuana and synthetic marijuana which pose a potential real threat for pregnant women.

High Potency Pot

They also express concerns that marijuana’s increased popularity among teenagers and young adults could put this group at higher risk.

“The emergence of bioengineered crops and novel, medicinal marijuana strains, means that marijuana is no longer what it used to be in the 1970’s and early 1980s’: some new, high potency strains, including some medicinal marijuana blends such as ‘Connie Chung’ and many others, contain up to 20 times more THC, the psychoactive constituent of marijuana, than did ‘traditional’ marijuana from the 1970’s and early 1980’s ” explains co-author Dr. Delphine Psychoyos from the Center for Genetic and Environmental Medicine at Texas A&M University. “Furthermore, with the emergence of dispensaries and Internet websites, high potency marijuana and Spice products are now readily available to the general population.”

Synthetic Cannabinoids

Spice products, a prominent brand of ‘synthetic marijuana’, or ‘fake weed’ mixtures, contain extremely potent THC analogues, also called ‘synthetic cannabinoids’, such as AM694 (found in Euphoric Blends Big Band and others) and HU210 (found in Spice Gold), both of which are 500-600 times more potent than marijuana’s THC.

“The THC contained in ‘high potency’ marijuana and the potent THC analogues contained in Spice products and other brands of ‘synthetic marijuana’, are potentially harmful to embryonic development, as early as two weeks after conception. This is because these psychoactive chemicals have the ability to interfere with the first stages in the formation of the brain of the fetus; this event occurs two weeks after conception, earlier than before signs of pregnancy appear. By the time a woman realises she is pregnant and stops taking these substances it may already be too late for her unborn child. ”

High Rate of Use

“Given that marijuana is the most widely used illicit drug by pregnant women worldwide – one study estimates the rate is as high as 20 per cent – this is a major issue.”

Recent research from the past 5 years has shown that marijuana exposure during pregnancy has been associated with anencephaly, a non-sustaining life condition where a large part of the skull or brain is absent, neurobehavioral deficiencies, such as attention deficit hyperactivity disorder, learning disabilities and memory impairment in toddlers and 10 year olds, as well as neuropsychiatric conditions, including depression, aggression and anxiety, in teens.

Increase Awareness Needed

“The problem is that many women who are pregnant, or are planning to become pregnant are totally unaware of this increased potency and the risks they pose,” says co-author Dr. Delphine Psychoyos. “This is because many websites on mothering and pregnancy, and those run by pro-marijuana advocacy groups, base their discussions on data collected prior to 1997, when no detrimental affects on pregnancy had been reported; It is important to note here that prior to 1997, pregnant women were mostly exposed to low potency, ‘traditional’ marijuana, which was the common form of marijuana in the market in the 1970’s and early 1980’s.”

“Marijuana has regained its popularity from the 1970s, especially among teens and young people, and has established social and cultural status as the most popular drug of abuse. Yet, like pregnant women, these young users probably have no idea of the significant increase in potency over the past four decades. ”

The researchers are calling for greater awareness among pregnant women about the availability of highly potent marijuana and synthetic cannabinoids such as those found in Spice products, and the risks that they can pose to their unborn child, even before their pregnancy has been confirmed.

They highlight the need to revise U.S. government bills and legislation to take account of the development of synthetic cannabinoids, such as those found in Spice and in new psychoactive substances that are based on cannabinoid research chemicals; They also question whether there is a need to put high potency marijuana in the highest category, if marijuana is to become legalised in America, based on its medical applications.

The authors also stress that teenagers and young people need to be more aware of the health risks of high potency marijuana, of synthetic cannabinoids found in Spice and other brands, and of synthetic cannabinoid research chemicals sold as designer drugs on various non DEA-regulated websites.

September 3rd, 2012  in Illegal Drugs No Comments »