An informant-based assessment of apathy in Alzheimer disease.

OBJECTIVE

To standardize a new rating scale for the assessment of apathy in Alzheimer disease (AD) and report on its reliability, structure, and relation to other clinical features of AD.

BACKGROUND

apathy is a common prominent behavioral syndrome accompanying AD and is associated with excess disability and increased caregiver burden. Current instruments for the assessment of apathy in AD do not explicitly and systematically attempt to differentiate limited activity and engagement due to lack of interest from inability or longstanding, premorbid personality traits. The present assessment, the Dementia Apathy Interview and Rating (DAIR), was developed taking these discriminations into account in question construction and interview format.

METHODS

One hundred participants (50% women) in the University Memory and Aging Center Research Registry with Probable or Possible AD (by NINCDS-ADRDA criteria) were assessed through caregiver interview or direct patient assessment for apathy, depression, and severity of cognitive and functional deficits. Item distribution characteristics, factor analysis, and evaluation of reliability were used to develop the final item set for the DAIR, and correlations with other measures were examined.

RESULTS

A 16-item unidimensional apathy scale with excellent internal consistency (alpha = 0.89) and temporal reliability ( = 0.85 over 2 months) was developed. Individual differences in apathy on the DAIR were unrelated to dysphoria. Apathy was significantly associated with functional and cognitive impairment, while depression was not.

CONCLUSIONS

The DAIR is a reliable informant-based assessment of apathy in persons with AD. Although apathy is assessed with respect to behaviors within the repertoire of patients, this behavioral syndrome remains associated with more severe deficits in cognitive and adaptive functioning. Associations between depression and dementia severity reported in some studies may reflect the confounding of apathy and depression in some assessment instruments.