TUESDAY, Oct. 19 (HealthDay News) -- Heavy alcohol and marijuana
use puts teenagers at risk for mental deficits that could persist
into adulthood, according to a new study.
The researchers found that teens who had abused alcohol and pot
scored lower than their abstinent peers on tests measuring a wide
range of intellectual abilities.
Robert Thoma, associate professor of psychiatry at the
University of New Mexico School of Medicine, the study's lead
author, said the researchers wanted to see if heavy substance abuse
caused "neuropsychological deficits" in teens similar to those
already shown in adult alcoholics and drug abusers.
"The worry is that kids who start drinking early, and drinking heavily, may be affected for their entire life. The data is just beginning to suggest this is true," said Thoma, a clinical neuropsychologist.
Thoma said the study is "too small to make any pronouncements,"
but is one of the first to show such deficits in teens with
substance abuse problems.
Memory was also negatively affected but only by marijuana, not
alcohol use, the study found.
Teens who did not use alcohol or drugs but had an alcoholic
parent showed deficits on a test measuring "visuospatial ability."
Visuospatial ability is the kind of non-verbal thinking involved in
creative pursuits such as architecture, music or art.
The study, reported online Oct. 19 in
Alcoholism: Clinical & Experimental Research, placed 48 teenagers, aged 12 to 18, into three groups: 19 in a substance-abusing study group, 15 healthy non-users in a control group and 14 non-users whose parents had been alcohol abusers. All 19 substance abusers were diagnosed with alcohol addiction or dependency. Twelve were also diagnosed with marijuana dependency.
The study-group teens, who were two years older on average than
the others, reported drinking six to 20 drinks a day during a
three-month period prior to the last time they drank. The more
alcohol consumed, the worse the teens scored on the battery of
tests, especially one measuring executive function.
Executive function includes decision-making, sustaining
attention, planning ahead and other skills teens are in the process
of developing "and will really need as adults," said Thoma.
The study-group teens reported spending 30 percent of the 90
days surveyed drinking heavily. Those who used marijuana recalled
spending 40 percent of that time period smoking marijuana.
"You can imagine how that may affect kids, how important attention and executive function are to developmental tasks," said Thoma. "Kids have to organize themselves, they have to get up early and get to school and sustain their attention to learn some very complicated things."
But Ramani Durvasula said the study might be "comparing apples
to oranges" because "kids who abuse drugs and alcohol are different
from those who don't," and may have other problems their peers do
"When talking about executive function -- control of inhibitions, planning ahead, behavior control -- if these things are already compromised in a child or adolescent, they're going to be more likely to do things like drink," said Durvasula, assistant professor of psychology at the School of Natural and Social Sciences of California State University, Los Angeles.
Noting the large amount of drinking reported by the teens she
cited possible problems in their homes.
"Let's face it, when kids are drinking 13 drinks a day (the study average), there's not a lot of parental supervision going on," said Durvasula.
Thoma acknowledged that the data might suggest that kids who had
poor executive function were more inclined to drink heavily.
"You have the chicken and the egg problem," said Thoma. "Which came first, the low executive function, which could lead to drinking more, or the heavy drinking, which leads to poor executive function?"
Though not "hard and fast," the correlations suggested that
alcohol was the problem, he said, adding, "in science there are
levels of how sure you can be about something."
Durvasula also said the six to 20 drinks a day reported by the
teens was "implausibly high." She recalled a study she did
involving crack-addicted inner-city adult men who only averaged
about eight drinks a day.
"They may have had a reporting problem," said Durvasula, also noting the large number of days the teens said they used drugs and alcohol.
The study did not control for socioeconomic level or education,
both closely associated with the kinds of mental functioning
measured in the study, said Durvasula.
Despite her comments, Durvasula said interventions are needed
"both in the schools, and home-based" for teens who are at risk of
Thoma said large longitudinal studies could sort out the causes
and effects in drug and alcohol-abusing teens, but noted the
research "remains severely underfunded."
For more on teens' drug and alcohol use, visit the
Substance Abuse and Mental Health Serv...s Administration.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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