Navigation Links
Pot Use-Low IQ Link Challenged in Study
Date:1/15/2013

By Randy Dotinga
HealthDay Reporter

MONDAY, Jan. 14 (HealthDay News) -- A new analysis challenges previous research that suggested teens put their long-term brainpower in danger when they smoke marijuana heavily.

Instead, the analysis indicated that the earlier findings could have been thrown off by another factor -- the effect of poverty on IQ.

The author of the new analysis, Ole Rogeberg, cautioned that his theory may not hold much water. "Or, it may turn out that it explains a lot," said Rogeberg, a research economist at the Ragnar Frisch Center for Economic Research in Oslo, Norway.

The authors of the initial study responded to a request for comment with a joint statement saying they stand by their findings. "While Dr. Rogeberg's ideas are interesting, they are not supported by our data," wrote researchers Terrie Moffitt, Avshalom Caspi and Madeline Meier. Moffitt and Caspi are psychology professors at Duke University, while Meier is a postdoctoral associate there.

Their study, published in August in the Proceedings of the National Academy of Sciences, attracted media attention because it suggested that smoking pot has more than short-term effects on how people think.

Based on an analysis of mental tests given to more than 1,000 New Zealanders when they were 13 and 38, the Duke researchers found that those who heavily used marijuana as teens lost an average of eight IQ points over that time period. It didn't seem to matter if the teens later cut back on smoking pot or stopped using it entirely.

In the short term, people who use marijuana have memory problems and trouble focusing, research has shown. So, why wouldn't users have problems for years?

"The question reminds me of something adults say when kids make weird faces: 'Careful, or your face will stay that way,'" Rogeberg said. "It is certainly possible that in the long term, heavy cannabis use has permanent or persistent effects on the brain. But to find out what these changes are and what they mean is not easy. We can't just look at the short-term effects and assume that these gradually become fixed and permanent over time."

In his report, Rogeberg used simulation computer modeling to argue that the initial study was possibly flawed because of the effects of poverty on IQ.

"Recent research indicates that IQ and brainpower are kind of like muscular strength: strengthened if it is regularly challenged. IQ is strengthened or sustained by taking education, studying hard, spending time with smart, challenging people, doing demanding work in our jobs," he said. "Some kids, unfortunately, are burdened with a poor home environment, poor self-control and conduct problems. These kids are likely to gradually shift away from the kinds of activities and environments that would exercise their IQs."

Rogeberg, whose report appears in this week's online issue of the Proceedings of the National Academy of Sciences, suggests that the initial study didn't properly take this into account. "Although it would be too strong to say that the results have been discredited, the methodology is flawed and the causal inference drawn from the results premature," he wrote.

In their response, the Duke researchers said that only 23 percent of the people they studied were from poor families, making it unlikely that these participants threw off the overall results. And, they added, their results were the same when they only focused on people from middle-class families.

The Duke team also noted that another group shows similar results from marijuana exposure: rats. And, as they pointed out, rats don't go to school or fall into rich, middle-class or poor categories.

More information

For more about marijuana, visit the U.S. National Library of Medicine.

SOURCES: Ole Rogeberg, Ph.D., research economist, Ragnar Frisch Center for Economic Research, Oslo, Norway; Terrie Moffitt, Ph.D., and Avshalom Caspi, Ph.D., professors, and Madeline Meier, Ph.D., research associate, Duke University, Durham, N.C.; Jan. 14-18, 2013, Proceedings of the National Academy of Sciences, online


'/>"/>
Copyright©2012 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Tampa Residents Challenged to Lose Weight for Cash
2. Are Rhesus Monkeys Musically Challenged?
3. Even Some Scientists Are Math-Challenged
4. Proposed testosterone testing of some female olympians challenged by Stanford scientists
5. Doctors Often Miss Signs of Problem Drinking in Patients, Study Finds
6. No Link Between Low Birth Weight, Asthma: Study
7. Study finds knee replacement surgery may lead to weight gain
8. NIH scientists identify protective role for antibodies in Ebola vaccine study
9. Thigh Is Safer Vaccination Site Than Arm for Toddlers, Study Finds
10. Saliva gland test for Parkinsons shows promise, study finds
11. Study finds poorer outcomes for obese patients treated for lumbar disc herniation
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Pot Use-Low IQ Link Challenged in Study
(Date:10/13/2017)... ... October 13, 2017 , ... Global Healthcare Management’s 4th Annual Kids Fun ... NJ. This free event, sponsored by Global Healthcare Management’s CEO, Jon Letko, is ... is geared towards children of all ages; it is a non-competitive, non-timed event, which ...
(Date:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: the Christian history ... The Brink” is the creation of published author, William Nowers. Captain Nowers and ... WWII veteran, he spent thirty years in the Navy. Following his career as ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... IsoComforter, Inc. ... products, announced today the introduction of an innovative new design of the shoulder pad. ... so you get maximum comfort while controlling your pain while using cold therapy. By ...
(Date:10/12/2017)... ... October 12, 2017 , ... HMP , a leader in healthcare ... Folio Magazine Eddie Digital Award for ‘Best B-to-B Healthcare Website.’ Winners were announced during ... , The annual award competition recognizes editorial and design excellence across a range of ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... of $3,296 in property taxes a year. In some states—like New York, New ... , By contrast, many overseas retirement havens have extremely low property-tax rates, which ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... Oct. 2, 2017 Diplomat Pharmacy, Inc. (NYSE: ... Software and Consulting, LLC , and named its founder ... based in Tennessee , will operate ... expands EnvoyHealth,s service offerings for health care partners to ... "In an interoperable world, technology ...
(Date:10/2/2017)... PHILADELPHIA , Oct. 2, 2017 Halo Labs announces ... particle analysis system called the HORIZON at MIBio 2017 in ... analyzes subvisible and visible particulate matter in biopharmaceutical samples with unprecedented ... use of the novel technique Backgrounded Membrane Imaging. ... The HORIZON subvisible particle analysis system ...
(Date:9/28/2017)... Cohen Veterans Bioscience and Early Signal Foundation ... and home sensors for real-time monitoring of patients with ... nonprofit organization focused on disruptive health solutions for rare ... system to record and integrate behavioral, cognitive, physiological and ... ...
Breaking Medicine Technology: