MONDAY, May 7, 2007 (HealthDay News) -- Teens who are glued to the TV for three or more hours a day are at higher risk for developing attention and learning problems, a new study suggests.
The research, led by Jeffrey G. Johnson of Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, also found that it was TV watching that contributed to learning problems -- not the other way around.
"Our findings suggest that teenagers who spent a lot of time watching TV tend to be more likely to have attention and learning problems that persist and interfere with their long-term educational achievement," said Johnson.
"Whether teens had existing attention or learning problems or whether they didn't have them, they were at greater risk for later attention and learning problems," Johnson said.
Johnson advises parents to limit the amount of time they let their children watch TV. "About one to two hours a day," he said. "And they should be watching quality programming," he added.
Video games can have the same effect as TV, Johnson said. "The problem with video games is that most of them have very little educational value. And some games may promote the development of attention problems," he said.
Johnson recommends limiting access to TV, for example not allowing a TV in the child's room. If the child has unrestricted access to TV, in the long-term they may have more difficulties reaching their potential as adults."
"Finding that increased television viewing in adolescence is associated with negative academic outcomes is not surprising," said Tara Stevens, assistant professor of educational psychology and leadership at Texas Tech University. "The interesting contribution of the study is that this relationship was still present when socio-economic status as well as prior attention and learning problems were statistically controlled," she added.
For some time, researchers have theorized that watching excessive amounts of entertainment TV might contribute to learning problems, because it takes time that might otherwise be spent reading and doing homework. TV watching also requires little intellectual effort.
In the study, Johnson and his colleagues collected data on 678 families from upstate New York. They interviewed parents and children about television habits and school problems. The interviews were conducted three times -- when the children were 14, 16 and 22 years old.
In addition, when the study participants reached age 33, they gave information about their secondary and post-secondary education, including whether they had graduated from high school or attended college.
When the children were 14 years old, 33 percent said they watched TV three or more hours a day. The researchers found that watching this much TV at 14 was associated with attention difficulties, failure to complete homework, boredom at school, failure to complete high school, poor grades, negative attitudes about school, overall academic failure in secondary school and failure to obtain post-secondary education.
Johnson's team also evaluated whether TV watching resulted in these problems or if children already prone to these problems watched this much TV.
"The results suggest that although youths with attention or learning problems may spend more time watching television than do youths without these difficulties, this tendency may be unlikely to explain the preponderance of the association between television viewing and attention and learning difficulties during adolescence," the study noted.
The researchers concluded that getting teens to watch less TV may help avoid learning problems.
The findings "suggest that by encouraging youths to spend less than three hours per day watching television, parents, teachers and health-care professionals may be able to help reduce the likelihood that at-risk adolescents will develop persistent attention and learning difficulties," the study authors said.
The results are published in the May issue of the Archives of Pediatrics & Adolescent Medicine.
Stevens said the findings need to be interpreted with caution. She said the study's conclusion "simply means that those who watch a large amount of television are at a disadvantage in comparison to those who do not."
"If television was a strong predictor of attention and learning problems, then we would see an increase in the diagnosis of both learning disabilities and attention disorders in adolescents along with an increase in their television viewing. At present, the majority of diagnoses in this category are made in elementary school," Stevens said.
Stevens does think, as does Johnson, that there's a need for increased weekend, summer and after-school activities that don't involve TV.
"Television viewing in adolescence is linked to a wide host of problems, including smoking and obesity," Stevens said. "Arguing over the strength and nature of its impact on learning and attention problems seems pointless when the cumulative evidence clearly points to the benefits of selective viewing in moderation."
In another study in the same issue of the journal, researchers found that many parents ignore warnings from the American Academy of Pediatrics (AAP) and let their infants watch television, DVDs or videos. By 3 months of age, some 40 percent of babies are regular viewers. By the time the children are 2 years old, the number jumps to 90 percent, said the researchers, led by Frederick Zimmerman, an associate professor of health services at the University of Washington.
"While appropriate television viewing at the right age can be helpful for both children and parents, excessive viewing before age three has been shown to be associated with problems of attention control, aggressive behavior and poor cognitive development. Early television viewing has exploded in recent years and is one of the major public health issues facing American children," the study authors wrote.
That finding gibes with another study, published Monday in the May issue of Pediatrics, which reported that only 32 percent of children between zero and age 2 watch no television, and as many as one in five youngsters under 2 even have a TV in their bedroom.
The American Academy of Pediatrics recommends that children 2 years old and under not watch TV at all.
To learn more about attention deficit hyperactivity disorder, visit the U.S. National Institute of Mental Health.