Warwickshire Children and Young People's Workforce

Brain development in adolescents

Dr Jay N Giedd, a psychiatrist, plus a number of other colleagues, have been studying brain development through Magnetic Resonating Imaging (MRI). They have found that the brain goes through two major pruning sessions during which grey matter (neurons) are pruned, but connections between them are strengthened. The first pruning takes place between birth and six years of age.

The second, more radical pruning, takes place around the onset of puberty and lasts until the mid twenties. In terms of brain development, his studies suggest that motor control is the first to develop, followed by language development and finally the higher order or executive functions of reasoning and judgement. This research would seem to explain why adolescents are more likely to indulge in risky behaviour.

He also suggests that faults in the pruning system at both ages could result in specific disorders (eg autism at the earlier stage and schizophrenia or bi-polar disorder at the later stage).

He has also discovered differences between brain development between males and females. Some of the research also attempts to map the brain development of young people with specific disorders (eg ADHD, Tourette’s etc) although this is not thought to be useful at present in diagnosis.

Listed below are links to web sites which give more details on aspects of the research.

www.pbs.org/wgbh/pages/frontline/shows/teenbrain/interviews/giedd.html

www.nimh.nih.gov/science-news/2004/imaging-study-shows-brain-maturing.shtml

www.nyas.org/ebriefreps/main.asp?intSubSectionID=343 This site gives a series of brief, related reports

www.teachersdomain.org/resources/tdc02/sci/life/reg/gieddweb/index.html

www.time.com/time/magazine/article/0,9171,994126,00.html