ADHD Drug Alters
the Brain in Young Children
A December 13, 2003 article
on WebMD, featured research showing that early use of the commonly
prescribed ADHD drug, Ritalin, can lead to depression later in life. This
evidence is based on new studies performed on rats. The article does note
that it is an open question as to whether what passes for depression in
lab rats has anything to do with depression in humans, but the evidence of
the effect on the brain, according to this study was clear.
The findings come from a
research team led by William A. Carlezon Jr., PhD, director of the
behavioral genetics laboratory at McLean Hospital and associate professor
at Harvard Medical School. The study appeared in the December 15, 2003
issue of Biological Psychiatry.
In a news release
Carlezon was quoted as saying, "Rats exposed to Ritalin as juveniles
showed large increases in learned-helplessness behavior during adulthood,
suggesting a tendency toward depression. These rats also showed
abnormally high levels of activity in familiar environments. This might
reflect basic alterations in the way rats pay attention to their
surroundings."
The article stated that
there are some close similarities between Ritalin and Cocaine. According
to the article, although Ritalin and Cocaine have different effects on
humans, their effects on the brain are very similar. The article noted
that when given to preteen rats, both drugs cause long-term changes in
behavior. Carlezon and colleagues explained that the drug short-circuits
the brain's reward system. That would make it difficult to experience
pleasure -- a "hallmark symptom of depression."
"These experiments
suggest that preadolescent exposure to Ritalin in rats causes numerous
complex behavioral adaptations, each of which endures into adulthood,"
Carlezon and colleagues conclude. "This work highlights the importance of
a more thorough understanding of the enduring neurobiological effects of
juvenile exposure to psychotropic drugs."
|