Accuracy of self-reported depression in persons with dementia
Lynn Snow A, Kunik ME, Molinari VA, Orengo CA, et al. ;
Commented by , 22 Mar 2005
Aim of the study
To investigate the reliability and validity of self-reported depression in demented elderly patients.
Method
Four diagnostic groups (27 controls, 37 dementia only, 28 depression only, 29 depression and dementia) of volunteer participants at least 60 years old, their informants and their clinicians, at the Houston Veterans Affairs nursing home and geropsychiatric inpatient unit and outpatient clinic were assessed using scales for depression, deficit awareness, functional disability, caregiver burden and severity of cognitive impairment.
The scales for depression included the Geriatric Depression Scale and the Cornell Scale for Depression in Dementia. Data were studied using analysis of variance, chi-square and regression analysis.
Results
Analysis of variance using informant- and clinician-rated depression categories found main effects on patient-reported depression scores for deficit awareness and depression diagnosis but not for dementia diagnosis. Chi-square analysis found that demented and depressed patients underreported depression at similar high rates compared to clinician and informant reports.
Regression analysis showed that deficit awareness accounted for a significant variance in self-reported depression accuracy, whereas clinician – or informant-rated depression, severity of cognitive impairment physical disability, functional status and caregiver burden were not significant.
Professor Gauthier's comments
The authors' conclusion is that the presence of dementia per se does not predict inaccurate depression self-reports, despite the deficit awareness which accounts for the majority of the variance in self-report accuracy.
They emphasize the need for investigations using both depression and dementia groups, larger sample size, and for more sensitive neuropsychological measures of executive functioning in order to better understand the effects of cognitive status on self-report.
The broader picture is that patients' reports matter and that the current difficulties in the treatment of neuropsychiatric symptoms of dementia, expertly reviewed by KM Sink, FK Holden and K Yaffe in JAMA 2005; 293: 596-608) may be better addressed using patients' input, as much as possible while taking into account their anosognosia or lack of awareness of their deficits.