New study shows early ritalin may cause long-term effects on...( or is simply immature or exuberant rel...),Health

In the work funded by the NIH, Dr. Carlezon and his chief collaborator, Dr. Susan Andersen, examined the effects of exposing rats to Ritalin during early development on behaviors later in life. They exposed normal rats to twice-daily doses of Ritalin during a period that is equivalent to approximately 4-12 years of age in humans. Examining the behavior during adulthood, Carlezon and Andersen conducted several types of tests that all showed that the animals had a reduced ability to experience pleasure and reward, particularly when it was measured by sensitivity to cocaine. In addition, they found that the animals exposed to Ritalin during pre-adolescence were more prone to express despair-like behaviors in stressful situations (such as swim tests) as adults. Overall, the animals showed more evidence of dysfunctional brain reward systems and depressive-like behaviors in adulthood.

These findings are critical because they suggest that Ritalin can have long-term consequences on normal-functioning brains. The study is particularly relevant when considering the difficulty in correctly diagnosing children with ADHD. In 1999, approximately 90 percent of children diagnosed with the disorder were taking Ritalin, with children beginning drug therapy at younger ages today, even during preschool in some instances. There is increasing evidence to suggest that correct diagnosis of ADHD is of the highest importance children who are misidentified as having ADHD and subsequently placed on prescription drug therapy could face possible impaired brain performance as adults.

"Ritalin can be highly effective in the treatment of ADHD, but our work highlights the importance of getting a proper diagnosis", states Carlezon. "Although individuals such as teachers and coaches can assist in identifying
'"/>

Contact: Jill Lobliner
jlobliner@gymr.com
202-745-5100
GYMR
12-Dec-2004