Apathy is one of the most common behavioural symptoms of amyotrophic lateral sclerosis (ALS), yet there are few studies that have investigated the relationship between apathy and quality of life (QOL) as they are experienced by the patient. A cohort of 60 ALS patients were evaluated using the Apathy Evaluation Scale which measured cognitive, behavioural, emotional and non-specific symptoms of apathy combined with the Personal Wellbeing Index, a multidimensional measure of QOL. The relationship between patient-rated apathy and QOL scores, controlling for potential clinical and psychological confounders were analysed using univariate and multivariate methods. Apathy was identified in 30% of ALS patients. Patients with apathy reported higher levels of depression (p = 0.0001). Compared to non-apathetic patients, patients with apathy had lower overall QOL (p = 0.001), most pronounced in the domains related to achievements in life (p = 0.001) and community-connectedness (p = 0.0001). Of the cognitive, behavioural, emotional and non-specific manifestations of apathy, only the emotional symptoms explained a significant amount of variance in achievements in life (p = 0.003) and community-connectedness (p = 0.001). As such, emotional manifestations of apathy may underlie worse QOL in ALS patients presenting with behavioural impairment. Patient-reported outcomes, particularly those assessing psychosocial functioning may be important for demonstrating the efficacy of interventions designed to improve QOL in ALS patients with behavioural impairment.
Keywords: Amyotrophic lateral sclerosis; Apathy; Depression; Motor neuron disease; Patient-reported outcome measures; Quality of life.