Increasing evidence suggests that there may be significant morphological changes in the neuropil of the dorsolateral prefrontal cortex in schizophrenia. A controversial issue surrounding these deficits in the cortical neuropil is the confounding effects of antipsychotic (neuroleptic) medication as well as the question of generality to psychiatric disorders. To begin to address these issues we examined brains from Huntington's patients matched to a cohort of schizophrenics and controls. Many Huntington's patients take neuroleptics similar to schizophrenics; therefore, by comparing the two groups to controls we can begin to determine if neuroleptics play a role in the deficits reported in schizophrenia. Using MAP2 immunohistochemistry and thionin staining eight matched triplets of Huntington, schizophrenia and control, in areas 9 and 17 layers III and V were analyzed. Our results confirmed previous published data showing a schizophrenia-associated decrease in MAP2 in area 9 with no change in area 17. Similarly the Huntington's patients showed no change in area 9 layer III and no change in area 17. There was however, a modest decrease observed in layer V area 9 of the Huntington's patients. Neuron density measurements showed no change in either layer or brain region in any of the diagnostic categories. These observations suggest that antipsychotic medication may not be responsible for some of the morphological changes observed in the neuropil of the PFC in schizophrenia.