Are there common core features of apathy in different neuropsychiatric samples as assessed by the Apathy Evaluation Scale?

Background: Previous factor analyses of the Apathy Evaluation Scale (AES) have indicated the presence of one main factor comprising core symptoms of apathy. However, the factor structure of the AES has not been determined in patient samples with cerebrovascular disorders. Aims of the study were to 1) examine the factor structure of the AES in two patient samples with cerebrovascular disorders (stroke and subarachnoid haemorrhage (SAH)) and to compare these results with those from a study of young patients with first-episode psychosis, 2) identify common items loading on the main factors and 3) examine whether these items could be used as an abbreviated scale for stroke and SAH patients. Methods: Factor analysis was conducted on AES data for all patients (stroke: n = 85; SAH: n = 76; first-episode psychosis; n = 104). Psychometric properties were explored. A second factor analysis was conducted on the stroke and SAH sample, based on common items loading on the main factor in all three samples. Results: A common main factor representing apathy was present in all samples. Ten common items loaded highest on the apathy factor in all samples. A scale consisting of these 10 items had sound psychometric properties for stroke and SAH patients (Cronbach's alpha = 0.91 and 0.95, respectively). Conclusions: The results suggested that common core items of apathy can be identified in various samples of patients with neuropsychiatric symptoms. We suggest a 10-item version of the AES that may be employed for assessing apathy in patients with SAH and stroke.