NEUROBEHAVIORAL AND NEURODIAGNOSTIC ASPECTS OF LATE-ONSET PSYCHOSIS

The onset of psychotic symptoms later in life requires careful multidi sciplinary evaluation, yet may pose significant diagnostic difficultie s given current classification schema. Here we describe a patient with new onset of schizophrenia-like symptoms at age 61. Cognitive screeni ng and laboratory tests were within normal limits. However, detailed n europsychological studies suggested mild to moderate, diffuse cerebral dysfunction, and MR revealed an arachnoid cyst around the right sylvi an fissure. Three annual follow-up evaluations demonstrated no additio nal cognitive deterioration. Neuropsychological findings are discussed along with limitations of current psychiatric nosology and cognitive screening tasks in older patients with new-onset psychosis.