Psychotropic medication-induced rabbit syndrome.

Rabbit syndrome (RS) is an involuntary movement disorder characterized by rapid, fine movements of an individual's mouth, similar to the chewing movements of a rabbit, and has most frequently been associated with the use of antipsychotic medications. RS is often unrecognized or misdiagnosed as tardive dyskinesia or pseudoparkinsonism. Although rare, RS is easily treatable if recognized.