Overcoming fear most difficult for teens: study
New York: Overcoming fear is even more difficult for adolescents than it is for children as teenagers` reactions to threat remain for sometime even when the danger is over, according to a new study.
Researchers led by Weill Cornell Medical College found that once a teenager`s brain is triggered by a threat, the ability to suppress an emotional response to the threat is diminished which may explain the peak in anxiety and stress-related disorders during this developmental period.
By contrast, the study shows that adults and children do not have the same trouble learning when a threat is no longer present.
"This is the first study to show, in an experiment, that adolescent humans have diminished fear extinction learning," says the study`s lead author, Dr Siobhan S Pattwell, a postdoctoral fellow at the Sackler Institute for Developmental Psychobiology at Weill Cornell.
"Our findings are important because they might explain why epidemiologists have found that anxiety disorders seem to spike during adolescence or just before adolescence," Pattwell said in a statement.
In the experiment, a group of volunteers - children, adolescents and adults - wore headphones and sweat meters and were asked to look at a computer screen with a sequence of blue or yellow square images.
One of the squares was paired with a really unpleasant sound. For example, 50 per cent of the time the blue square would set off the noise.
If the participants acquired a fear of the noise, they showed increased sweat when viewing the image that was paired with it.
The same group was brought back the next day, and again viewed a sequence of blue or yellow squares, but this time there was no associated noise.
"But teenagers didn`t decrease their fear response, and maintained their fear throughout subsequent trials when no noise was played," researchers said.
The researchers found that unlike the teens participating in this study aged 12-17, both children and adults quickly learned that neither square was linked to a noxious sound, and this understanding rapidly decreased their fear response.
The mouse experiment, which used standard fear conditioning common in these types of animal studies, obtained similar findings.
Adolescent mice (29 days old) did not decrease their fear response to stimuli that no longer existed, but younger and older mice did. Interestingly, the adolescent mice never lost their fear response as they aged.
The study was published in the journal Proceedings of the National Academy of Sciences.