CDR computerized assessment system

The CDR computerized assessment system (CDR system) is a computerized battery of cognitive tests designed in the late 1970s by Professor Keith Wesnes at the University of Reading in Berkshire, England, for repeated testing in clinical trials. Task stimuli are presented in a laptop computer and participants respond via 'YES' and 'NO' buttons on a two-button response box, which records both the accuracy and reaction time.

The CDR system is a computer based cognitive testing tool, developed to assess both enhancement and impairment of human cognitive performance. The CDR system's simplicity, sensitivity and specificity makes it acceptable to be used in clinical trials with either healthy subjects or diseased patient populations. The CDR system software is loaded onto laptop computers for testing in medical clinics. An internet version of the CDR system is available using keyboard commands to measure responses. Ancillary equipment is used for specific cognitive tests such as a postural stability (sway) meter, a critical flicker fusion device or joysticks for CDR's tracking test.

The CDR system is a series of brief neuropsychological tests that assess major aspects of cognitive function known to be influenced by a wide variety of factors including trauma, fatigue, stress, nutrition, ageing, disease (both physical and mental), medicines and drugs. The standard battery of cognitive tests in The CDR system includes immediate/delayed word recall, word recognition, picture recognition, simple reaction time, digit vigilance, choice reaction time, numeric working memory, and spatial working memory. Individual tests can be added to or removed from the battery to target specific cognitive domains. Examples of tests that can be added include measurements of executive function, mood states, social cognition, motor function and postural stability. The standard battery of tests lasts 18 minutes.

The CDR system tasks have proven validity in definitively measuring cognitive function in a variety of domains including attention, working memory, episodic secondary memory, executive function, and motor skill.

In September, 2009, Cognitive Drug Research was acquired by United BioSource Corporation. UBC division Bracket continues to offer the CDR System for use in clinical research.

See alsoEdit


  • Wesnes, K.A.; McKeith, I.G.; Ferrara, R.; Emre, M.; Del Ser, T.; Spano, P.F.; Cicin-Sain, A.; Anand, R.; Spiegel, R. (March 2002). "Effects of Rivastigmine on Cognitive Function in Dementia with Lewy Bodies: A Randomised Placebo-Controlled International Study Using the Cognitive Drug Research Computerised Assessment System". Dementia and Geriatric Cognitive Disorders. 13 (3): 183–192. doi:10.1159/000048651. PMID 11893841.
  • Simpson, Pauline M.; Surmon, D.J.; Wesnes, Keith A.; Wilcock, G.K. (February 1991). "The Cognitive Drug Research Computerized Assessment System for Demented Patients: A Validated Study". International Journal of Geriatric Psychiatry. 6 (2): 95–102. doi:10.1002/gps.930060208.
  • Nicholl, Claire G.; Lynch, Sean; Kelly, Cornelius A.; White, Linda; Simpson, Pauline M.; Wesnes, Keith A.; Pitt, Brice M.N. (March 1995). "The cognitive drug research computerized assessment system in the evaluation of early dementia-is speed of the essence". International Journal of Geriatric Psychiatry. 10 (3): 199–206. doi:10.1002/gps.930100306.
  • Moon, G.; Manktelow, T.C. (2002). "Cognitive deficits in recently diagnosed untreated patients with Parkinson's disease". Journal of Psychopharmacology. 16 (Suppl): A31.
  • McKeith, I.; Del Ser, T.; Spano, P.; Emre, M.; Wesnes, K.; Anand, R.; Cicin-Sain, A.; Ferrara, R.; Spiegel, R. (16 December 2000). "Efficacy of rivastigmine in dementia with Lewy bodies: a randomised, double-blind, placebo-controlled international study". The Lancet. 356 (9247): 2031–2036. doi:10.1016/S0140-6736(00)03399-7. PMID 11145488.
  • Macher, J.-P. (2004). "Modafinil reverses the marked attentional deficits produced by acute sleep deprivation in healthy volunteers". Journal of Psychopharmacology. 18 (Suppl): A48.
  • Harrington, Frances; Saxby, Brian K.; McKeith, Ian G.; Wesnes, Keith; Ford, Gary A. (December 2000). "Cognitive Performance in Hypertensive and Normotensive Older Subjects". Hypertension. 36 (6): 1079–1082. doi:10.1161/01.HYP.36.6.1079. PMID 11116128.
  • Wesnes, K.; Neuman, E.; de Wilde, H.J.G.; Malbezin, M.; Crijns, H.J.M.J.; Jonkman, J.H.G.; Guez, D. (1994). "Pharmacodynamic effects of a repeated oral administration of 4 dose levels of S 12024-2 in 36 elderly volunteers". Neurobiology of Aging. 15 (Suppl 1): S100. doi:10.1016/0197-4580(94)92864-9.
  • Walker, M.P.; Ayre, G.A.; Cummings, J.L.; McKeith, I.G.; O'Brien, J.T.; Ballard, C.G. (25 April 2000). "Quantifying fluctuation in dementia with Lewy bodies, Alzheimer's disease, and Vascular Dementia". Neurology. 54 (8): 1616–1625. doi:10.1212/WNL.54.8.1616. PMID 10762503.
  • Zhang, K; Mayleben, D; Roth, A; Corser, B; Nandy, P; Harris, S; Perhach, J (2004). "Dose and time dependent discrimination of daytime sleepiness measured by multiple sleep latency tests (MSLT), Psychomotor performance tests (PPT) and Stanford Sleepiness Scale (SSS) after a single AM administration of a sedative hypnotic drug". Sleep. 27: A49.
  • Simpson, P.M. (1994). "The construct validity of the cognitive drug research computerised assessment system". Journal of Psychopharmacology. 8 (Suppl): A20.
  • White, L; Simpson, P; Herting, R; Schwartz, P (1994). "Further evaluations of the criterion validity of the CDR computerised assessment system". Journal of Psychopharmacology. 8 (Suppl): A21.
  • Wesnes, Keith A. (September 2000). "The value of assessing cognitive function in drug development". Dialogues in Clinical Neuroscience. 2 (3): 183–202. PMC 3181606. PMID 22033754.

Further readingEdit