THE PREVALENCE OF PSYCHOTIC, DEPRESSIVE AND ANXIETY SYNDROMES IN DEMENTED AND NONDEMENTED 85-YEAR-OLDS

One-month prevalence of mental syndromes in demented and non-demented subjects was studied in a representative sample of 85-year-olds living in Gothenburg, Sweden (N = 494). All subjects were examined by a psychiatrist. Schizophreniform syndrome was significantly more common in subjects with Alzheimer's disease than in non-demented subjects (13% vs 1%, p < 0.001), and more common in severe dementia (p < 0.01). Depressive syndromes were significantly more common in subjects with mild dementia than in non-demented subjects (34% vs 20%, p < 0.05). Phobic syndrome was less common in demented than in non-demented subjects. It is hypothesized that the occurrence of mental syndromes in demented subjects may be related to structural and neurochemical brain changes.