by Dr. Meenakshy Varier on  February 16, 2017 at 11:29 AM Health Watch
  • It is often difficult to differentiate between symptoms of depression and cognitive disorder.
  • A new study states that single photon emission computed tomography, or SPECT, can help to distinguish between depression or a cognitive disorder.
  • This neuroimaging technique differentiates between the two disorders by measuring the differences in blood flow in multiple brain areas of the brain.

Brain Imaging Helps Distinguish Between Depression and Dementia
Single photon emission computed tomography, or SPECT, can help to distinguish between depression or a cognitive disorder (CD) such as Alzheimer's disease.

Since both disorders have overlapping symptoms it is often difficult for clinicians to tell them apart to make an appropriate diagnosis.

"This is a critical clinical question that has practical implications for patient management and treatment," explained lead researcher and psychiatrist Daniel G. Amen, MD.

"These disorders have very different prognosis and treatments and being able to improve diagnostic accuracy can improve outcomes for some patients." Amen added.

The authors write, "Cognitive impairment is present in approximately half of persons who have late onset depression and depression is evident in 9-65% of individuals with dementia. Studies have indicated that the prevalence of depression in patients with mild cognitive impairment is 25%. Consequently, it is often challenging to diagnostically disentangle depression and cognitive disorders from one another."

"One of the greatest new insights of the past decade is the linkage of depression to the psychology of late life cognitive decline. Raji and coworkers extend the approach to the biological substrate by an elegant imaging approach. These studies further place brain aging on a firm biological basis," added George Perry, PhD, Editor-in-Chief of the Journal of Alzheimer's Disease and Dean and Professor of Biology University of Texas at San Antonio.


For the study, 4541 subjects were examined, 847 had been diagnosed with dementia, 3269 with depression, and 425 with both conditions.

The researchers used brain SPECT imaging, a nuclear medicine study.

It measures blood flow and activity and researchers found that there was reduced blood flow in multiple brain areas of the brain in people with cognitive disorders compared to those with depression, particularly in the hippocampus, temporal, and parietal lobes.

Researchers found that SPECT could distinguish depression from CDs with 86% accuracy.

In people with both depression and cognitive disorders, brain SPECT imaging showed the ability to distinguish both with 83% accuracy.

The new article is published in the Journal of Alzheimer's Disease.


  1. Daniel G. Amen et al. Classification of Depression, Cognitive Disorders, and Co-Morbid Depression and Cognitive Disorders with Perfusion SPECT Neuroimaging. Journal of Alzheimer's Disease; (2017) DOI: 10.3233/JAD-161232

Source: Medindia

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