Young brains and drugs
Neuroscientist, DA offer useful info on the effects of drugs, alcohol on teen brains
GREENFIELD — From the age of 6 we go through life with about three pounds of squishy stuff behind our eyes responsible for everything we do and think, and what we put in our bloodstreams before our mid-20s has a particularly potent impact on where that brain takes us.
Six is the age that brain size and weight plateau, Dr. Marisa M. Silveri told an assembly of middle and high school students Wednesday, but the human brain remains in a particularly sensitive state of development until the age of 20-22, during which time drugs and alcohol can easily throw a wrench in its delicate mechanics.
“What is the point of having a body that can live for a very long time if you don’t have a brain to go with it?” Silveri asked.
The Northwestern District Attorney’s second annual Youth Conference on Substance Abuse Prevention brought middle and high school students from a handful of Franklin and Hampshire county schools to Greenfield Community College for a school day dedicated to making good decisions and influencing peers to do the same.
Drinking or drug abuse before the age of 22 or so has a particularly potent impact not only on immediate motor skills and decision-making but brain function for years to come, according to Silveri.
“What we’re learning is that during adolescence you’re in a period of life where you’re building your efficiency this is actually one of the most important times in your life for building something that is supposedly going to sustain you for the rest of your life,” she said.
Sliveri is an assistant professor of psychiatry at Harvard Medical School and a neuroscientist specializing in the intersection of developing brains and mind-altering substances from alcohol and marijuana to cocaine and heroin.
When the brain stops growing it continues developing within it’s new confines, insulating the connective fibers between some neurons or brain cells and pruning away less efficient neurons to accommodate these beefed-up connections.
Connections, for instance between the amygdala, home to instinctive reaction and quick responses, and the frontal lobe or thought center. Brain scans show neurons firing in the amygdala when teenagers are shown a picture of food healthy adult brains show activity in both the amygdala and frontal lobe.
The difference between an unconsidered response and the right choice for a teenager can be as little as 10 seconds, Silveri said, and she advises teens to take 10 seconds when presented with a decision to give their frontal lobe time to put the brakes on their impulsive amygdala.
The question is not how much of your brain you have at your disposal, it’s how efficiently it does what it’s supposed to, she said.
“There is that idea that you only ever use 10 percent of your brain, that is absolutely a myth. You use all of your brain all the time, it is so fantastically wired and biomechanically synchronous that you have to use all of the components,” Silveri said.
Surprisingly, Silveri said, it takes more alcohol relative to body weight — two to seven times as much — to impair a teenager’s motor functions than an adult’s, taking away an important cue that they’ve had enough.
While it might take two to three times as much alcohol to set a teenager staggering, a teenager’s hippocampus, or memory center, is significantly more impaired than an adult’s, she said, and not just while under the influence.
Memory tests conducted on non-drinking teenagers show an ability to draw a relatively complicated geometric doodle from memory with an average of 80 percent accuracy, she said, a B grade.
“However, if you look at teens who are drinkers, now let me stress something, these are not teens who are intoxicated while they are doing these tasks, these are not teens with alcohol disorders, these are teens who drink on weekends, these are teens who recreationally use alcohol, .... what we basically know is they don’t get a B grade, they don’t get a C grade, they get a D grade,” she said.
Conversely, brain scans of marijuana-users show increased neural activity when performing tasks that should require less, which Silveri likened to competing in a sprint with a backpack of bricks; more work for a weaker result.
In addition to harming memory and decision-making at a sensitive stage, Silveri said early alcohol or drug use strongly increases the user’s chance of addiction later in life.
“If you’re 13 and you start to drink, you have a 47 percent chance that you’re going to be addicted ... if you wait until you’re 14, or 15 or 16, for every year that you wait to start drinking your risk for an addiction goes down significantly,” Silveri said.
Even at the legal drinking age the odds are still at 9 percent, she said, and the possibility of developing an addiction never goes away.
Silveri’s talk focused on the substances statistically most commonly abused by teens; drugs and alcohol, but she said later the same holds true for other drugs on an amplified scale.
“(The effects are) way more pronounced, there’s a bigger abuse liability, so it will take less to become addicted,” she said. “Some of it sadly is about exposure. Some people happen to have prescriptions available, and kids are curious and they try it and they get addicted quicker.”
That’s not to say it’s OK to go with the less-addictive option, she said.
“Nothing is best, but the prescription opioids in particular are really the most highly addictive, so you see that transition from initiation to abuse to addiction a lot quicker, and that’s all linked to decision-making ability.”
The good news, Silveri said, is that the brain can recover from the neurological effects of drug and alcohol use early in life, but it takes time and depends on the depth of the damage.
Northwestern District Attorney David Sullivan said “We really want the kids to start thinking about making good decisions earlier in their lives.”
Students from Northampton High School, Pioneer Valley Performing Arts Charter Public School, Smith Vocational and Agricultural School, Jabish Middle School and Turners Falls, Greenfield, Easthampton, Northampton, Ware and Belchertown high schools attended.
Sullivan told students the goal of the exercise was to give them the knowledge to make positive decisions and to be positive influences on their friends.
You can reach Chris Curtis at:
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