Brief commentary: Under-recognition of underuse of clozapine in treating psychotic symptoms in Parkinson's disease

Clozapine is an important drug in the treatment of Parkinson's disease (PD). It has proven efficacy in treating PD psychosis without worsening motor function, as well as in treating tremor refractory to L-Dopa, yet it is severely underused in the United States. Unlike the situation of treatment resistant schizophrenia, this underuse is underrecognized.