title: Digital Clock Drawing: differentiating "thinking" versus "doing" in younger and older adults with depression.
abstract: Psychomotor slowing has been documented in depression. The digital Clock Drawing Test (dCDT) provides: (i) a novel technique to assess both cognitive and motor aspects of psychomotor speed within the same task and (ii) the potential to uncover subtleties of behavior not previously detected with non-digitized modes of data collection. Using digitized pen technology in 106 participants grouped by Age (younger/older) and Affect (euthymic/unmedicated depressed), we recorded cognitive and motor output by capturing how the clock is drawn rather than focusing on the final product. We divided time to completion (TTC) for Command and Copy conditions of the dCDT into metrics of percent of drawing (%Ink) versus non-drawing (%Think) time. We also obtained composite Z-scores of cognition, including attention/information processing (AIP), to explore associations of %Ink and %Think times to cognitive and motor performance. Despite equivalent TTC, %Ink and %Think Command times (Copy n.s.) were significant (AgeXAffect interaction: p=.03)-younger depressed spent a smaller proportion of time drawing relative to thinking compared to the older depressed group. Command %Think time negatively correlated with AIP in the older depressed group (r=-.46; p=.02). Copy %Think time negatively correlated with AIP in the younger depressed (r=-.47; p=.03) and older euthymic groups (r=-.51; p=.01). The dCDT differentiated aspects of psychomotor slowing in depression regardless of age, while dCDT/cognitive associates for younger adults with depression mimicked patterns of older euthymics.
authors.affiliation: 1Department of Psychiatry,University of Illinois at Chicago,Chicago,Illinois.
authors.forename: Jamie
authors.initials: J
authors.lastname: Cohen
authors.affiliation: 2The Lahey Clinic,Burlington,Massachusetts.
authors.forename: Dana L
authors.initials: DL
authors.lastname: Penney
authors.affiliation: 3MIT Computer Science and Artificial Intelligence Laboratory,Cambridge,Massachusetts.
authors.forename: Randall
authors.initials: R
authors.lastname: Davis
authors.affiliation: 4Department of Neurology,Drexel University,Philadelphia,Pennsylvania.
authors.forename: David J
authors.initials: DJ
authors.lastname: Libon
authors.affiliation: 5University of North Dakota School of Medicine and Health Sciences,Grand Forks,North Dakota.
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Swenson
authors.affiliation: 1Department of Psychiatry,University of Illinois at Chicago,Chicago,Illinois.
authors.forename: Olusola
authors.initials: O
authors.lastname: Ajilore
authors.affiliation: 1Department of Psychiatry,University of Illinois at Chicago,Chicago,Illinois.
authors.forename: Anand
authors.initials: A
authors.lastname: Kumar
authors.affiliation: 1Department of Psychiatry,University of Illinois at Chicago,Chicago,Illinois.
authors.forename: Melissa
authors.initials: M
authors.lastname: Lamar
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000209:etiology*; D003863:Depression / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011596:Psychomotor Disorders / Q000209:etiology*; D012307:Risk Factors; D013223:Statistics as Topic; D020521:Stroke / Q000175:diagnosis; D013850:Thinking / Q000502:physiology*; D013997:Time Factors