Thursday, September 16, 2010

Atypical Antipsychotic Drugs and Stuttering

Stuttering may be caused by excessive dopaminergic activity in the motor neuron section of the brain. More specifically, it is the dopaminergic activity in the nigrostriatal pathway involved in motor function that has been implicated in stuttering. On the other hand, excessive dopaminergic activity in the mesolimbic pathway involved with emotion and memory has been linked to schizophrenia. Since individuals who stutter generally do not exhibit schizophrenic tendencies, the levels of dopaminergic activity are obviously unique to different parts of the brain.

In several of the previous posts, we indicated that one way to inhibit the activity of dopamine is to enhance GABAergic activity, which can be accomplished with BZs or pagoclone. Although the claim has been made that stuttering is linked to too much dopaminergic activity, the problem may be that there is too little GABAergic activity in the relevant sections of the brain. There are other drugs that may enhance GABAergic activity and we will discuss these in future posts.

But in this post, we want to discuss more direct approaches to limiting dopaminergic activity, namely through a class of drugs called atypical antipsychotics. These drugs, which include Risperidone, Zyprexa and Abilify, were designed to treat conditions such as bipolar disorder, schizophrenia, mania, and delusional disorder. More recently, they have been used off-label to treat stuttering.

These drugs work directly in that they block dopamine receptors (namely the D2 receptors) on neurons so that dopamine that is present in the synapses cannot itself bind to these receptors. In this way, the activity of dopamine is reduced.

This variety of drug therapy has been strongly promoted by Dr. Gerald Maguire, the director of the Kirkup Center for the Medical Treatment of Stuttering at the University of California, Irvine. For those who are interested, the web-site of the Center is:


Unfortunately, atypical antipsychotics may have some side effects such as sedation, dyskinesia (involuntary muscle twitching) and may lead to weight gain and potentially diabetes. Major research is currently being conducted to develop a new generation of atypical antipsychotics exhibiting reduced drug side effects.

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