A Teenager health issues Blog by Donie

MRI studies show Teenager's abuse of drink and drug's is linked to brain 'wiring'

    

In this MRI of a brain (side view), the green, yellow and red areas indicate bundles of 

neurons involved in addiction. Red represents reward pathways; green and yellow signify habitual responses.

TEENAGERS who binge drink and take drugs may have differently wired brains - meaning they could be screened for their risk of substance abuse.

Newly discovered networks of neurons suggest some youngsters are more likely to begin smoking, experimenting with cannabis or consuming large amounts of alcohol.

Scientists used MRI (magnetic resonance imaging) scans to highlight abnormalities by comparing the brains of almost two thousand 14 year olds.

It is the first time the vast and chaotic actions of a teenage brain at work have been shown in such detail.

The findings, published online in Nature Neuroscience, helps answer a longstanding chicken-or-egg question about whether certain brain patterns come before drug use, or are caused by it.

Psychiatrist Professor Hugh Garavan, of the University of Vermont in New England, said: "The differences in these networks seem to precede drug use."

One key breakthrough showed diminished activity in a network involving an area known as the orbitofrontal cortex which is involved in decision making was linked with experimentation with alcohol, cigarettes and illegal drugs in early adolescence.

Co author Dr Robert Whelan said "these networks are not working as well for some kids as for others," making them more impulsive.

Prof Garavan said faced with a choice about smoking or drinking, the 14 year old with a less functional impulse-regulating network will be more likely to say, "'yeah, gimme, gimme, gimme!', and this other kid is saying, 'no, I'm not going to do that.'"

He said testing for lower function in this and other brain networks could one day be used by researchers as "a risk factor or biomarker for potential drug use."

The researchers were also able to show other newly discovered networks are connected with the symptoms of attention-deficit hyperactivity disorder (ADHD). These are distinct from those associated with early drug use.

In recent years, there has been controversy and extensive media attention about the possible connection between ADHD and drug abuse. Both ADHD and early drug use are associated with poor inhibitory control - they are problems that plague impulsive people.

But the new research shows these apparently related problems are regulated by different networks in the brain - even though both groups of teens can score poorly on tests of their "stop-signal reaction time," a standard measure of overall inhibitory control used in studies such as this.

This strengthens the idea that the risks of ADHD and drug abuse are not necessarily associated, as recent research suggests.

The connected impulsivity networks revealed by increased blood flow begin to paint a more distinct portrait of the neurobiology underlying the patchwork of attributes and behaviours psychologists call impulsivity.

They also shed light on the capacity to put brakes on these impulses, a set of skills sometimes called inhibitory control.

Addiction expert Prof Edythe London, of the University of California, Los Angeles, who was not part of the study, described it as "outstanding."

She said the work "substantially advances our understanding of the neural circuitry that governs inhibitory control in the adolescent brain."

Using a complex mathematical formula, the researchers were able to fish out seven networks involved when impulses were successfully inhibited and six others when inhibition failed.

Dr Whelan said these networks "lit up" when participants were asked to perform a repetitive task involving pushing a button on a keyboard, but were then able to successfully stop - or inhibit - the act in mid-flow. Those with better inhibitory control were able to succeed faster.

But the underlying networks behind these tasks could not have been detectable in a typical scanner study of about sixteen or twenty people.

Dr Whelan said: "This study was orders of magnitude bigger, which lets us overcome much of the randomness and noise - and find the brain regions that actually vary together."

The researchers said that teenagers push against boundaries, and sometimes take risks, is as predictable as the sunrise. It happens in all cultures and even across all mammal species. Adolescence is a time to test limits and develop independence.

But death among teenagers in the industrialised world is largely caused by preventable or self-inflicted accidents launched by impulsive risky behaviours, and often associated with alcohol and drug use.

Additionally, "addiction in the western world is our number one health problem," said Prof Garavan. He said: "Think about alcohol, cigarettes or harder drugs and all the consequences that has in society for people's health."

Understanding brain networks that put some teenagers at higher risk for starting to use them could have large implications for public health.

Added Prof Garavan: "The take-home message is that impulsivity can be decomposed, broken down into different brain regions, and the functioning of one region is related to ADHD symptoms, while the functioning of other regions is related to drug use."

Skin cancer concerns on the increase among teenagers

     

Anatomy of the skin, showing the epidermis, dermis, and subcutaneous tissue.

The use of tanning beds is said to be contributing to the rise in melanoma cases among young people.

Persuading teenagers to avoid tanning beds and the beach is a war James Spencer is losing.

They don't care that more Americans – especially young adults – are being diagnosed with skin cancer every year, the St. Petersburg dermatologist said. His practice that used to serve a mostly older clientele now gets patients 20 years and younger every month.

"They're not worried about skin cancer at 40," Spencer said. "They want to be hot for the prom this weekend."

The American Cancer Society estimates 3.5 million Americans will be diagnosed with basal cell or squamous cell skin cancers in 2012. An additional 76,250 will be told they have melanoma, the more serious skin cancer responsible for a majority of the more than 12,000 annual deaths.

Local dermatologists and the H. Lee Moffitt Cancer Center in May will offer a series of free skin cancer screenings to catch suspicious growths and lesions. Skin cancer is highly treatable when detected early.

But this awareness campaign – dubbed "Melanoma May" – also has a strong prevention message aimed at one high risk group: teenagers.

Moms are diligent lathering up little ones, but doctors know the practice doesn't continue when children are around their peers, they say. Or they don't want to repeatedly apply sunscreen.

"We would like to put it on at 8 a.m. and forget about it," Spencer said. "It doesn't work like that."

Childhood sun exposure is significant: the average American experiences 75 percent of lifetime sun exposure before the age of 18. Burns and other extensive exposure are linked to an increased risk of skin cancer later in life.

Many teens shun sunscreen and flock to commercial tanning salons, said Vernon Sondak, program director for Moffitt's cutaneous oncology program. They don't understand the long-term value of sunscreen protection.

Though legal, Sondak says tanning salons should be regulated. Tobacco, a known carcinogen, is illegal for people younger than 18. Similar restrictions should be placed on tanning beds, as UV ray exposure is known to cause skin cancers, he said.

"It's no different than smoking cigarettes or doing drugs," Sondak said. "No mom says, 'When you kids grow up, you can do drugs.' "

He points to a Mayo Clinic study published in March, which revealed an eight-fold increase in first-time diagnosis of melanoma for young women between 1970 and 2009. The small study of several hundred adults in a Minnesota community blamed tanning beds for part of the increased cancers.

That's a claim the Indoor Tanning Association disputes.

"The authors make a leap of pure speculation to suggest that rising melanoma rates may have a connection to indoor tanning," the group said in a statement.

Regardless of the source of cancer-causing ultraviolet rays, melanoma rates continue to increase, by about 3 percent a year for white adults, said the cancer society's annual Cancer Facts & Figures report. Surgeries to remove melanomas also are rising, new research shows.

Teens need to know the consequences of treating basal cell and squamous skin cancer can be painful, said Spencer, chairman of the American Academy of Dermatology's skin cancer committee.

They may not get cancer now, but it won't look pretty down the road, he said.

"No, you don't die from it, but it can be quite mutilating and disfiguring," Spencer said. "It's still a tragedy."