Related Experiment Video
Updated: Aug 2, 2026

The 4 Mountains Test: A Short Test of Spatial Memory with High Sensitivity for the Diagnosis of Pre-dementia Alzheimer's Disease
Published on: October 13, 2016
Validation of a cognitive test for delirium in medical ICU patients
R P Hart1, J L Levenson, C N Sessler
1Department of Psychiatry, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0268, USA.
Abstract:
Patients with delirium, dementia, depression, and schizophrenia were administered a newly developed test designed to identify delirium in an intensive care unit (ICU) setting. Two alternate forms of the Cognitive Test for Delirium (CTD) were highly correlated. The delirium patients performed least well, and an optimal cutoff score derived from relative-operating characteristic analysis resulted in a sensitivity of 100% and a specificity of 95%. In a follow-up study, the Mini-Mental State Exam could not be administered to 42% of the ICU patients who completed the CTD. Early identification of delirium with the CTD may lead to timely treatment of specific etiologic conditions and a reduction in mortality and morbidity.

