Self-, collateral- and clinician assessment of depression in persons with cognitive impairment

Objectives: This investigation examined the associations between self-reports, collateral-source reports and a clinician's diagnosis of depression in persons with cognitive impairment. Method: Responses on the Geriatric Depression Scale - 15 (GDS-15) from 162 participants with a diagnosis of Mild Cognitive Impairment (n = 78) or Alzheimer's Dementia and a Mini-Mental State score 15 (n = 84) were compared with both their collateral sources' report on either the Neuropsychiatric Inventory Questionnaire (n = 93) and/or the collateral-source GDS-15 (n = 67), or a clinician's diagnosis of Major Depression (MD). Results: Significant differences were seen between self- versus collateral-source reports of depression in these participants. Participants' reports of loss of interest (anhedonia) significantly increased the odds of disagreement with their collateral sources (OR = 3.78, 95% CI: 1.3-11.2) while reports of negative cognitions significantly decreased the odds of such a disagreement (OR = 0.31, 95% CI: 0.1-0.9). The symptom of anhedonia also showed the strongest association with the clinician's diagnosis of MD. Conclusion: A motivational symptom like loss of interest was seen to play an important role in depression experienced by those with cognitive impairment.