Measuring Antisocial Behaviors in Behavioral Variant Frontotemporal Dementia With a Novel Informant-Based Questionnaire

Objective: Antisocial behaviors are common and problematic among patients with behavioral variant frontotemporal dementia (bvFTD). In the present study, the investigators aimed to validate an informant-based questionnaire developed to measure the extent and severity of antisocial behaviors among patients with dementia. Methods: The Social Behavior Questionnaire (SBQ) was developed to measure 26 antisocial behaviors on a scale from absent (0) to very severe (5). It was administered to 23 patients with bvFTD, 19 patients with Alzheimer's disease, and 14 patients with other frontotemporal lobar degeneration syndromes. Group-level differences in the presence and severity of antisocial behaviors were measured. Psychometric properties of the SBQ were assessed by using Cronbach's alpha, exploratory factor analysis, and comparisons with a psychopathy questionnaire. Cluster analysis was used to determine whether the SBQ identifies different subgroups of patients. Results: Antisocial behaviors identified by using the SBQ were common and severe among patients with bvFTD, with at least one such behavior endorsed for 21 of 23 (91%) patients. Antisocial behaviors were more severe among patients with bvFTD, including the subsets of patients with milder cognitive impairment and milder disease severity, than among patients in the other groups. The SBQ was internally consistent (Cronbach's a50.81). Exploratory factor analysis supported separate factors for aggressive and nonaggressive behaviors. Among the patients with bvFTD, the factor scores for aggressive behavior on the SBQ were correlated with those for antisocial behavior measured on the psychopathy scale, but the nonaggressive scores were not correlated with psychopathy scale measures. The k-means clustering analysis identified a subset of patients with severe antisocial behaviors. Conclusions: The SBQ is a useful tool to identify, characterize, and measure the severity of antisocial behaviors among patients with dementia.