Paroxysmal Perceptual Alteration: Drug-Induced Phenomenon or Schizophrenic Psychopathology?

Brief and repetitive episodes of perceptual changes, termed paroxysmal perceptual alteration (PPA), have been described in association with antipsychotic treatment. We report a case of paranoid schizophrenia who had such perceptual changes akin to PPA for 15 years, that was not related to antipsychotic treatment. There was a rapid resolution of PPA following treatment with low dose clonazepam.