Neurological changes could boost risks for ADHD, other problems, researchers say

From HealthDay

Being exposed to alcohol before birth may lead to behavioral problems later on, U.S. researchers report.

Heavy prenatal alcohol exposure does not always lead to fetal alcohol syndrome, noted a team reporting in the August issue of Alcoholism: Clinical & Experimental Research. In some cases, it can cause cognitive and behavioral problems without the facial features characteristic of fetal alcohol syndrome.

In their study, researchers at San Diego State University (SDSU) examined 22 children and adolescents (ages 8 to 18 years) — 13 with and 9 without histories of heavy prenatal alcohol exposure. The participants were part of a larger study at the Center for Behavioral Teratology, SDSU.

The participants who were exposed to heavy alcohol before birth had altered responses in the frontal-striatal areas of the brain.

“We found two regions within the prefrontal cortex where the youth with alcohol-exposure histories had increased brain activation and one area in the subcortex (called the caudate nucleus) where the alcohol-exposed youth had decreased brain activation,” study co-author Susanna L. Fryer, a graduate student in the SDSU/University of California, San Diego, joint doctoral program in clinical psychology, said in a prepared statement.

These brain regions are thought to be involved with the inhibition of behavior. In fact, the participants with alcohol exposure were also at greater risk for attention deficit hyperactivity disorder (ADHD) and other psychiatric diseases linked with poor control of inhibition.

“Prenatal alcohol exposure can cause damage to the brain that results in significant problems with regulating behavior and optimal thinking and learning,” Fryer said.

From ScienceDaily.com

In youth with attention deficit hyperactivity disorder (ADHD), the brain matures in a normal pattern but is delayed three years in some regions, on average, compared to youth without the disorder, an imaging study by researchers at the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) has revealed. The delay in ADHD was most prominent in regions at the front of the brain’s outer mantle (cortex), important for the ability to control thinking, attention and planning. Otherwise, both groups showed a similar back-to-front wave of brain maturation with different areas peaking in thickness at different times.

“Finding a normal pattern of cortex maturation, albeit delayed, in children with ADHD should be reassuring to families and could help to explain why many youth eventually seem to grow out of the disorder,” explained Philip Shaw, M.D., NIMH Child Psychiatry Branch, who led research team.

Previous brain imaging studies failed to detect the developmental lag because they focused on the size of the relatively large lobes of the brain. The sharp differences emerged only after a new image analysis technique allowed the researchers to pinpoint the thickening and thinning of thousands of cortex sites in hundreds of children and teens, with and without the disorder.

“If you’re just looking at the lobes, you have only four measures instead of 40,000,” explained Shaw. “You don’t pick up the focal, regional changes where this delay is most marked.”

Among 223 youth with ADHD, half of 40,000 cortex sites attained peak thickness at an average age of 10.5, compared to age 7.5 in a matched group of youth without the disorder.

Shaw, Judith Rapoport, M.D., of the NIMH Child Psychiatry Branch, Alan Evans, M.D., of McGill University, and colleagues report on their magnetic resonance imaging (MRI) study during the week of November 12, 2007, in the online edition of the Proceedings of the National Academy of Sciences.

The researchers scanned most of the 446 participants — ranging from preschoolers to young adults — at least twice at about three-year intervals. They focused on the age when cortex thickening during childhood gives way to thinning following puberty, as unused neural connections are pruned for optimal efficiency during the teen years.

In both ADHD and control groups, sensory processing and motor control areas at the back and top of the brain peaked in thickness earlier in childhood, while the frontal cortex areas responsible for higher-order executive control functions peaked later, during the teen years. These frontal areas support the ability to suppress inappropriate actions and thoughts, focus attention, remember things from moment to moment, work for reward, and control movement — functions often disturbed in people with ADHD.

Circuitry in the frontal and temporal (at the side of the brain) areas that integrate information from the sensory areas with the higher-order functions showed the greatest maturational delay in youth with ADHD. For example, one of the last areas to mature, the middle of the prefrontal cortex, lagged five years in those with the disorder.

The motor cortex emerged as the only area that matured faster than normal in the youth with ADHD, in contrast to the late-maturing frontal cortex areas that direct it. This mismatch might account for the restlessness and fidgety symptoms common among those with the disorder, the researchers suggested.

They also noted that the delayed pattern of maturation observed in ADHD is the opposite of that seen in other developmental brain disorders like autism, in which the volume of brain structures peak at a much earlier-than-normal age.

The findings support the theory that ADHD results from a delay in cortex maturation. In future studies, the researchers hope to find genetic underpinnings of the delay and ways of boosting processes of recovery from the disorder.

“Brain imaging is still not ready for use as a diagnostic tool in ADHD,” noted Shaw. “Although the delay in cortex development was marked, it could only be detected when a very large number of children with the disorder were included. It is not yet possible to detect such delay from the brain scans of just one individual. The diagnosis of ADHD remains clinical, based on taking a history from the child, the family and teachers.”

Also participating in the research were: Kristen Eskstrand, Wendy Sharp, Jonathan Blumenthal, Dede Greenstein, Liv Clasen, and Jay Giedd, M.D., NIMH.

The National Institute of Mental Health (NIMH) mission is to reduce the burden of mental and behavioral disorders through research on mind, brain, and behavior.

From ScienceDaily

Pycnogenol, from the bark of the French maritime pine tree, may reduce attention-deficit hyperactivity disorder in children, a study found.

The study, published in the journal Nutritional Neurosciene, shows Pycnogenol balances stress hormones, which lowers adrenaline and dopamine, resulting in a decrease of ADHD.

The study sampled 57 outpatients with ADHD with an average age of 9 years in Slovakia.

Forty-one patients received Pycnogenol and 16 received a placebo. Patients were not supplemented with any other drugs or with vitamins E or C during the study.

Participants in the Pycnogenol group received 1 milligram of Pycnogenol or placebo for every kilogram of body weight, daily, for one month, said study author Dr. Peter Rohdewald of the University of Munster, in Germany. Stress hormones were quantified from urine samples.

The researchers found Pycnogenol lowered stress hormones — adrenaline by 26.2 percent, and dopamine by 10.8 percent.

“The findings acknowledge that children with ADHD have dramatically elevated levels of stress hormones known to increase heart rate and blood pressure, causing excitement, arousal and irritability, as compared to children without ADHD symptoms,” Rohdewald said.

From MedlinePlus

Watching more than two hours of television daily during childhood increases the likelihood of attention problems in adolescence, according to a new study.

Yet far from settling the debate, the findings add more confusion to the debate on whether television viewing might contribute to attention problems. The new research largely agrees with one previous study but disagrees with two others.

“I wouldn’t advocate that watching TV is a good thing,” said Tara Stevens, assistant professor of educational psychology at Texas Tech University in Lubbock, who in 2006 published a study finding no link between television viewing and hyperactivity disorder. “I’m just not sure there’s a direct relationship between having a disorder and watching TV. I don’t think that’s definitive. This is one important piece to the argument, but it is still not the end,” she said.

The current study is published in the September issue of Pediatrics and led by Robert John Hancox of the University of Otago in Dunedin, New Zealand. His team monitored the television-viewing habits of more than 1,000 children born in Dunedin in 1972 and 1973 between the ages of 5 and 15, as well as reports of attention problems at ages 13 and 15.

The authors determined that watching more than two hours of television per day between the ages of 5 and 11 increased the likelihood of attention problems in adolescence, with each hour of television viewing increasing the risk of “high adolescent attention problems” — that is, the top 10 percent of attention difficulties — by about 40 percent. This association held even after accounting for gender, socioeconomic status, early attention problems, and early cognitive ability.

“We found the amount of television did predict the amount of problems at age 13 and 15,” Hancox said. “And these effects were not explained by early attention problems.”

The team further found that TV watching during childhood and adolescence were independently associated with attention problems, suggesting that time in front of the television leads to both short- and long-term effects.

“Childhood TV viewing was associated with attention difficulties regardless of what you watch as an adolescent,” he explained. “The amount of TV watched between 5 and 11 predicted problems between ages 13 and 15 regardless of what you watch between 13 and 15.”

That doesn’t mean it would be pointless to curtail your child’s viewing habits now, he said. But it might only relieve short-term damage and not any longer-term effects.

“You may not be able to reverse what happened in childhood, but you can stop compounding the problem,” he said.

The take-home message, Hancox concluded, is that parents should heed the American Academy of Pediatrics’ recommendations, which say that children under two should watch no television at all, and that children over the age of two should watch no more than two hours per day — recommendations that are in line with his findings

“This increase in risk kicked in with people who watched two hours of television per day,” Hancox said. “For those who watched less, there was no increase in risk.”

Hancox’s findings are in general agreement with a 2004 study led by Dr. Dimitri Christakis of the Seattle’s Children’s Hospital and Regional Medical Center, which found a relationship between television watching at age 3 and attention problems at age 7. Yet they contradicted both Stevens’ 2006 study, which found no link between TV viewing at age 5 and attention deficit-hyperactivity disorder at age 6, and an additional study out of Denmark.

Stevens lauded Hancox’s effort. Yet she noted that, as a correlational study, it says nothing at all about causation. In that sense, it cannot answer a key question: Does TV viewing cause kids’ attention problems, or do the parents of children with attention problems drop them in front of the TV more often to keep them occupied?

Additionally, the study makes no distinctions about what the children are watching, how much they are paying attention, and so on. Finally, Stevens questioned the lack of several key statistical variables.

“I would say there is some ambiguity in the results, because some statistical values were omitted,” she said. “I wouldn’t necessarily have come to the same conclusion with just the information they reported. I would be more confident in my conclusion if I knew they had looked at these other values.”

Hancox’s findings are published in the same issue of Pediatrics as another study, which found that the vast majority of TV food ads directed at children and adolescents promote foods that are high in fat, sugar, and sodium, and low in nutritional content.