Identifying Neurocognitive Impairment in Depression Using Computerized Testing

Abstract

There is considerable interest in the identification of neurocognitive impairment in patients with depression. The purpose of this study is to illustrate a methodology for identifying frank neurocognitive impairment in clinical practice and research using a computerized battery of neuropsychological tests. Participants were 100 adult patients with depression who were not on antidepressants. They were carefully matched on age, education, gender, and ethnicity to 100 healthy adult control subjects. All participants completed the Central Nervous System Vital Signs (CNS-VS) computerized assessment battery, which takes approximately 30–40 minutes to administer. Patients with depression performed more poorly than controls on all five domain scores (Cohen's d ranged from d = .37 to .72). When using two or more scores below the 5th percentile as the cutoff for frank neurocognitive impairment, 31.0% of the depressed sample and only 5.0% of the control sample scored in this range. In this study, patients with depression were 8.5 times more likely to have two or more index scores that were below the 5th percentile. Computerized testing, using the interpretive methodology presented, represents an efficient methodology for identifying cognitive problems in patients who present with untreated depression.

Key words:

• assessment
• computerized testing
• depression
• neuropsychological

Acknowledgement

The authors thank Dr. C. Thomas Gualtieri for providing all the data used in this study. Dr. Gualtieri is one of the developers of the CNS-VS battery used in this study. The authors thank Jennifer Bernardo for her assistance with manuscript preparation. Dr. Grant Iverson has received research funding from the CNS-VS publishing company and grant funding from AstraZeneca and the Alcohol Beverage Medical Research Council for research involving this test battery. Dr. Brian Brooks has received research support from the CNS-VS publishing company and grant funding from AstraZeneca for research involving this test battery. Dr. Allan Young is a co-investigator on a grant funded by AstraZeneca that uses the CNS-VS battery as an outcome measure. No funding, however, was provided for this study.

Notes

Note. SD = Standard Deviation. Degrees of freedom for t test was (198).

Note. The Neurocognition Index is the average of the five domain (index) scores. SD = Standard deviation. VBM = Verbal Memory; VIM = Visual Memory; SAT = Shifting Attention Test; CPT = Continuous Performance Test. By convention, Cohen's effects sizes are interpreted as follows: .2 = small, .5 = medium, and .8 = large (Cohen, 1988). Degree of freedom for all analyses of variance was (1, 198).

Note. SD =Standard deviation. Values represent the cumulative percent of participants with low scores. These analyses involved considering performance across the five domain (index) scores simultaneously.