Featured Research

from universities, journals, and other organizations

Combined chronic alcohol and marijuana use during youth can compromise white-matter integrity

Date:
December 14, 2012
Source:
Alcoholism: Clinical & Experimental Research
Summary:
Chronic alcohol and marijuana during youth is associated with worsened neurocognitive abilities into later adolescence and adulthood. A new study examines fiber tract integrity affected by adolescent alcohol and marijuana use for 1.5 years. Results support previous findings of reduced white-matter integrity in these youth.

Chronic use of alcohol and marijuana during youth is associated with poorer neural structure, function, and metabolism, as well as worsened neurocognitive abilities into later adolescence and adulthood. This may be due to biological and psychosocial transitions occurring during adolescence that impart increased vulnerability to neurotoxic influences. A study of longitudinal changes in fiber tract integrity associated with adolescent alcohol and marijuana use during 1.5 years supports previous findings of reduced white-matter integrity in these youth.

Results will be published in a special online issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"Research has shown differences in the brains of teens who use alcohol and marijuana as compared to teens who do not use these drugs or report only very infrequent, minimal use," said Joanna Jacobus, postdoctoral fellow at the University of California, San Diego as well as corresponding author for the study. "Alcohol and marijuana may have a negative impact by altering important cellular communication in the brain, preventing development of new healthy cells, and/or causing inflammation, which can adversely impact healthy brain development in many ways. For example, the results can lead to changes in brain structure such as volume, and function such as activity."

"The areas of the brain that are composed mostly of connecting axons have been termed 'white matter,' since these areas appear white in color," added Duncan Clark, associate professor of psychiatry at the University of Pittsburgh Medical Center. "However, prior research has not clearly demonstrated that this white matter disorganization is caused by alcohol or marijuana use. In some studies where adolescents are studied only once, white matter disorganization may have been present prior to alcohol or marijuana use."

"The teen brain is continuing to develop, so many neural systems are not yet fully matured, as compared to adults' brains," said Jacobus. "Brain connections important for inhibiting risky behaviors are still forming, and some youth are more likely to choose immediate effects, such as alcohol or marijuana use, over long-term benefits."

Clark agreed. "Maturation of the brain during adolescence is thought to be the foundation for self-control," he said. "The developing adolescent brain, compared to the fully developed adult brain, is also probably more vulnerable to alcohol neurotoxicity. Adolescents are vulnerable to loss of control and, when this loss of control involves substance use, excessive or risky substance use can have adverse consequences."

For 18 months, the researchers followed 92 adolescents (63 males, 29 females), ages 16 to 20 years, divided into two groups: 41 with extensive alcohol and marijuana use histories by mid-adolescence, and 51 with consistently minimal if any substance use. Participants were part of an ongoing longitudinal study of substance use in adolescence with teens recruited from local schools from 2005 to 2007. Both groups received diffusion tensor imaging and detailed substance use assessments, along with toxicology screening, at baseline and 18-month follow-ups -- 182 scans in all -- as well as interim substance-use interviews every six months.

"We found evidence for poorer white matter tissue health in teens who engage in heavy alcohol and marijuana use compared to those who abstain," said Jacobus. She noted that white matter, the "information highway of the brain," allows for quick and efficient communication between brain regions. Compromised white matter can mean slower cognitive processing and poorer cognitive performance such as memory, attention, and decision-making.

"As to whether there were differences in these teens before they began using alcohol and marijuana is difficult to determine, but we found that increasing alcohol use over 1.5 years in late adolescence was related to a decline in white matter health 18 months later, supporting a negative effect of alcohol use on the brain despite potential pre-existing differences," Jacobus said.

"White matter organization was particularly compromised in an area called the superior longitudinal fasciculus," added Clark. "This is one of the major connection roadways in the brain. When the connections between brain areas are severely damaged, those areas of the brain cannot properly function. While the more subtle deficit shown here may impair functioning, the degree of deficit involved is not likely to be obvious in day-to day functioning. However, we are concerned that even these subtle deficits in brain microstructure may lead to diminished self-control."

"Our findings underscore that early initiation of alcohol and marijuana use can have negative implications on the brain" said Jacobus. "We hope this information can be communicated to teens to help them understand why drinking during adolescence is discouraged. In the future, biomarkers such as tissue health may help identify teens that are particularly vulnerable for engaging in riskier behaviors such as drinking."


Story Source:

The above story is based on materials provided by Alcoholism: Clinical & Experimental Research. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sunita Bava, Joanna Jacobus, Rachel E. Thayer, Susan F. Tapert. Longitudinal Changes in White Matter Integrity Among Adolescent Substance Users. Alcoholism: Clinical and Experimental Research, 2012; DOI: 10.1111/j.1530-0277.2012.01920.x

Cite This Page:

Alcoholism: Clinical & Experimental Research. "Combined chronic alcohol and marijuana use during youth can compromise white-matter integrity." ScienceDaily. ScienceDaily, 14 December 2012. <www.sciencedaily.com/releases/2012/12/121214190942.htm>.
Alcoholism: Clinical & Experimental Research. (2012, December 14). Combined chronic alcohol and marijuana use during youth can compromise white-matter integrity. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2012/12/121214190942.htm
Alcoholism: Clinical & Experimental Research. "Combined chronic alcohol and marijuana use during youth can compromise white-matter integrity." ScienceDaily. www.sciencedaily.com/releases/2012/12/121214190942.htm (accessed July 24, 2014).

Share This




More Mind & Brain News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Do Obese Women Have 'Food Learning Impairment'?

Do Obese Women Have 'Food Learning Impairment'?

Newsy (July 18, 2014) Yale researchers tested 135 men and women, and it was only obese women who were deemed to have "impaired associative learning." Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins