SPECT findings on psychosis in Alzheimer's disease

Am J Psychiatry. 1995 Oct;152(10):1470-5. doi: 10.1176/ajp.152.10.1470.


Objective: This study examined whether psychosis in Alzheimer's disease is associated with cerebral perfusion patterns appreciable by single photon emission computed tomography (SPECT) scans.

Method: All cooperative outpatients enrolled in an Alzheimer's disease research center with the diagnosis of probable Alzheimer's disease and a Clinical Dementia Rating of mild or moderate were interviewed with their primary caregivers. Current and past psychiatric functioning was assessed by using the Hamilton Depression Rating Scale, the Structured Clinical Interview for DSM-III-R, and the Behavioral Pathology in Alzheimer's Disease Rating Scale. Patients without premorbid psychosis received SPECT scans, and the scans of the patients with delusions or hallucinations (N = 30) were compared to the scans of patients without these symptoms (N = 16).

Results: The patients with delusions (N = 29) had hypoperfusion of the left frontal lobe in relation to the right frontal lobe. The patients with hallucinations (N = 10) had hypoperfusion in the parietal lobe.

Conclusions: Psychotic patients with Alzheimer's disease had a pattern of cerebral blood flow deficits significantly different from that of nonpsychotic patients. This suggests that patterns of cerebral dysfunction may be expressed symptomatically as psychosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alzheimer Disease / diagnosis*
  • Alzheimer Disease / diagnostic imaging
  • Alzheimer Disease / epidemiology
  • Ambulatory Care
  • Brain / blood supply
  • Brain / diagnostic imaging*
  • Cerebrovascular Circulation*
  • Comorbidity
  • Delusions / diagnosis
  • Delusions / diagnostic imaging
  • Frontal Lobe / blood supply
  • Frontal Lobe / diagnostic imaging
  • Hallucinations / diagnosis
  • Hallucinations / diagnostic imaging
  • Humans
  • Organotechnetium Compounds
  • Oximes
  • Parietal Lobe / blood supply
  • Parietal Lobe / diagnostic imaging
  • Psychiatric Status Rating Scales
  • Psychotic Disorders / diagnosis*
  • Psychotic Disorders / diagnostic imaging
  • Psychotic Disorders / epidemiology
  • Technetium Tc 99m Exametazime
  • Tomography, Emission-Computed, Single-Photon*


  • Organotechnetium Compounds
  • Oximes
  • Technetium Tc 99m Exametazime