ADD and Ritalin

[Fernando Boix]

Andrew Ray <aray at emory.edu> wrote:


>I don't know if anyone actually knows exactly.  One theory I've heard is that 
>GABAergic transmission is lower than it should be in certain areas.  Ritalin, 
>according to this theory, is supposed to stimulate GABA transmission.  This 
>results in a net inhibitory effect, and is supposed to be why Ritalin reduces 
>the hyperactivity and increases ability to concentrate.  I don't know if the 
>theory has much evidence for or against it (I've seen a few studies advancing 
>the theory, but I didn't really look at them in depth), nor do I know of other 
>theories that are out there.  It's not really my specialty, but maybe this can 
>give you a jumping off point for further research.  Good luck.

>Andrew Ray
>Emory University Neuroscience Program

Methylphenidate, the active compound of Ritalin, is a potent dopamine
uptake blocker, like cocaine, increasing the concentration of this
neurotransmitter in the synaptic cleft and increasing, therefoere, the
dopaminergic neurotransmission. Amphetamine, which is also used in
ADD-ADHD, also increases dopamine neurotransmission but in another way
(not very good known but it seems it increase dopamine release by
reversing the uptake mechanisms). 
--
Fernando Boix Escolan
Dept. of Neurophysiology
University of Oslo