Akinesia, tardive dysmentia, and frontal lobe disorder in schizophrenia.

Two iatrogenic effects of antipsychotic medications other than tardive dyskinesia have been recently described in schizophrenic populations: akinesia and tardive dysmentia. These effects involve activational, cognitive, and affective rather than motor changes, and closely resemble two most common prefrontal syndromes: dorsolateral and fronto-orbital/mediobasal. It is possible that the widely reported "frontal lobe dysfunction" in some chronic schizophrenic patients at least in part reflects iatrogenic changes in the mesolimbic/mesocortical dopamine system, which projects extensively into prefrontal areas. The degree of iatrogenic versus genuine contribution to the frontal lobe dysfunction in schizophrenia needs to be ascertained further, and the heterogeneity of known frontal lobe syndromes must be taken into account in describing schizophrenic populations. The mechanisms of noniatrogenic contributions to the frontal lobe dysfunction in schizophrenia may reflect a variety of anatomical sources and require further examination.