Background: Existing mood measures for individuals with Alzheimer's disease and related dementias (AD-RD) focus primarily on negative moods, including depression.
Objective: The objectives of this study were to design and test a new measure of both positive and negative moods in individuals aged 55 years or older with mild to severe AD-RD.
Methods: Formal and informal caregivers' observations of mood in this population generated 26 positive and 27 negative mood descriptors reviewed by content experts before pilot testing. The AD-RD Mood Scale and Mini-Mental State Examination were administered to 298 participants with very mild to severe cognitive impairment. Two examiners simultaneously rated a subsample of participants, a second subsample was retested after 2 weeks, and additional mood measures were administered to a third subsample.
Results: The final AD-RD Mood Scale contains 34 items in two positive subscales (spirited and contented) and three negative subscales (hostile, apathetic, and sad). The five subscales explain 82% of the variance. Cronbach's alpha values were .92, .90, .85, .77, and .73 for the spirited, hostile, contented, apathetic, and sad subscales, respectively. Interrater reliability ranged from .88 to .63. Mean subscale scores were stable over time. Moderate to strong validity coefficients (Pearson's r) produced by comparison with four existing measures were in the hypothesized direction. Subscale scores discriminated between participants who are depressed and those who are nondepressed.
Discussion: The final 34-item AD-RD Mood Scale provides useful data on both positive and negative moods of individuals with AD-RD. Further evaluation of reliability and validity in a multiethnic sample is recommended, as are confirmatory factor analysis and expansion to add subscales related to tension and social unease.