Multidimensional apathy in ALS: validation of the Dimensional Apathy Scale

Area of Science:

• Neurology
• Psychiatry
• Behavioral Science

Background:

• Apathy is a common symptom in amyotrophic lateral sclerosis (ALS), often complicated by physical limitations.
• Traditional apathy assessment treats it as a single dimension, overlooking its complex nature.
• The Dimensional Apathy Scale (DAS) was developed to assess three distinct subtypes of apathy (Executive, Emotional, Initiation) in motor-disabled individuals.

Purpose of the Study:

• To investigate the substructure of apathy in ALS.
• To evaluate the reliability and validity of the DAS in patients with ALS and their caregivers.
• To understand the specific apathy profile in ALS.

Main Methods:

• Recruited patients with ALS and their carers from the Scottish Motor Neurone Disease Register.
• Administered the Dimensional Apathy Scale (DAS), Apathy Evaluation Scale, and Geriatric Depression Scale-Short Form.
• Included 83 patients, 75 carers, and 83 matched healthy controls for comparison.

Main Results:

• Patients with ALS exhibited significantly higher initiation apathy and lower emotional apathy compared to controls.
• DAS patient and carer versions showed comparable scores.
• The DAS demonstrated good internal consistency reliability and convergent/discriminant validity.
• No correlation was found between DAS scores and functional disability (ALSFRS).

Conclusions:

• Apathy in ALS is characterized by increased initiation and decreased emotional dimensions.
• The Dimensional Apathy Scale (DAS) is a valid and reliable tool for assessing multidimensional apathy in ALS.
• The DAS provides a nuanced understanding of apathy beyond global measures in ALS.