The pitfalls of substance abuse have been hammered into teenagers in their formative years, from overdose and addiction to incarceration and drug-related violence. But a growing field of research and brain science shows there's yet another reason for youngsters to just say no.
Advances in technology have revealed the teenage brain is only about 80 percent developed, and recent studies suggest adolescents are particularly vulnerable to the long-term "neurotoxic" effects from heavy use of drugs like marijuana and alcohol. Cognitive shortfalls are most severe among teens who start using younger and continue the habit for longer periods of time.
"There's a lot of emerging data pointing in the direction that early drug use may have deleterious effects on memory and learning," said Ken C. Winters, a professor of psychiatry at the University of Minnesota. "It adds a whole new layer of drug harm to humans and to the community."
Adolescence already presents a high risk for drug abuse as teens are more likely to try new things or accede to peer pressure. The teenage brain is geared to seek pleasure, finds it in drugs but isn't mature enough to grasp the long-term consequences of drug abuse.
"People do look at brain development as one important feature when we think about vulnerability to drugs," adds Winters, noting hormonal surges also impact decision making. "But the jury is still out on exactly how brain development might alter teenagers' vulnerability."
Drugs interfere with the function of neurotransmitters, a hijacking that can harm developing neural connections. Teens respond differently to drugs than adults do and are "sensitive to neurological assault by psychoactive substances," according to the Science and Management of Addiction Foundation.
"More than any other age group adolescents are at risk for substance addiction, and more than any other age group they risk permanent intellectual and emotional damage due to the effects of drugs," the organization warns on its website.
A first-of-its-kind study conducted recently in New Zealand showed significant declines in the IQs of participants who smoked marijuana heavily in their teen years. Such a loss "could mean your earning power is less," said Winters, who wasn't involved in the study but said its results were telling.
"Your ability to cope with life's stress might be less," he added. "Your socioeconomic status in any given community you live in might be less, as well as your ability to handle daily trials and tribulations. You might not remember as much."
Seeking to measure marijuana's long-term effect on brain functioning, researchers in the New Zealand study evaluated participants at 13 years old -- before they'd begun to light up -- and again at 38, after a pattern of consistent marijuana use had developed.
"Persistent cannabis use was associated with neuropsychological decline broadly across domains of functioning, even after controlling for years of education," said the study, published this year in the Proceedings of the National Academy of Sciences of the United States of America, a scientific journal.
Adolescent-onset users saw greater drops than those who began the habit as adults. In fact, the study added that "adult-onset cannabis users did not appear to experience IQ decline as a function of persistent cannabis use."
The authors of the study said their findings highlighted the need for prevention efforts geared toward adolescents, particularly at a time of resurgent marijuana use among teenagers. A national survey last year found that daily marijuana use had reached a 30-year peak among high school seniors, perhaps in part because youth today have a lower "perceived risk" of its effects than their older siblings did.
Brain imaging has debunked an earlier belief that the brain was fully developed at or around puberty. Instead, experts now believe the brain is still maturing until about age 24 or 25, a finding that could have widespread ramifications as scientists gain a fuller understanding of how teens tick.
Overconsumption of alcohol also has been found to have a detrimental effect on the teenage mind, disrupting processes and hampering attention and the brain's executive function. An American Medical Association report noted a study that compared magnetic resonance imaging of the brains of 14- to 21-year-olds who abused alcohol to nondrinkers.
It found drinkers to have a 10-percent smaller hippocampus -- the brain region responsible for learning and memory -- a potentially irreversible reduction.
"Results of recent neuroscience research have substantiated the deleterious effects of alcohol on adolescent brain development and added even more evidence to support the call to prevent and reduce underaged drinking," reads a revised policy statement issued by the American Academy of Pediatrics.
Mary Wilburn, executive director of the Lazarus Society in Phenix City, said she's seen the psychological impact of drugs first hand in addicts she's counseled. Within her own family, she said her brother-in-law's mental ability seemed to be "changed forever" after someone slipped him a heavy dose of LSD at a party when he was just a child.
"It's like they're stuck at whatever age they were when all of this stuff started," Wilburn said. "Even without drugs, they're spacey because there's permanent damage there."
Michelle, a 42-year-old recovering addict and ex-con, began abusing drugs when she was 14 but says she's been clean about seven months. Substance abuse -- including a lengthy methamphetamine addiction -- stripped nearly everything from the Phenix City woman, who asked that her last name be withheld because she's hoping to find work.
Today, Michelle still has short-term memory problems she attributes to her years of addiction -- "I set something down and I can't find it" -- though she's made significant strides in her G.E.D. classes. "Now that I've been clean," she said, "my memory is starting to come back and I remember things when I was a teenager -- where it left off."
No comments:
Post a Comment