Distinct Patterns of Socioemotional Dysfunction Relate to Aggressive Versus Nonaggressive Rule-breaking Antisocial Behaviors in Behavioral Variant Frontotemporal Dementia.

Background: Antisocial behaviors occur in up to 91% of individuals with behavioral variant frontotemporal dementia (bvFTD). Prior work has shown that antisocial behaviors can be differentiated into aggressive and nonaggressive rule-breaking behavioral subtypes. Socioemotional dysfunction is common in bvFTD and unique compared to other types of dementia.

Objective: To determine whether socioemotional dysfunction relates to general antisocial behaviors in individuals with bvFTD, or whether different types of socioemotional dysfunction relate to aggressive versus rule-breaking behaviors.

Methods: Informants for 28 participants with bvFTD and 21 participants with Alzheimer disease (AD) completed the Social Behavior Questionnaire (SBQ) and the Interpersonal Reactivity Index (IRI). The SBQ measures the presence and severity of 26 antisocial behaviors, including subscales for aggressive behaviors (SBQ-AGG) and nonaggressive rule-breaking behaviors (SBQ-RB). The IRI measures cognitive and emotional empathy capabilities, including subscales for Empathic Concern (IRI-EC) and Perspective-taking (IRI-PT).

Results: As expected, participants with bvFTD had higher scores on the SBQ in total than participants with AD, as well as on the SBQ-AGG and SBQ-RB separately. Participants with bvFTD had lower scores on the IRI-EC and IRI-PT than participants with AD (P < 0.0001 for all measures). Lower scores on the IRI-PT correlated with higher scores on the SBQ-AGG-but not with higher scores on the SBQ-RB-across the combined group of participants (P = 0.007), and within participants in the bvFTD group (P = 0.01) specifically, after controlling for covariates of age, sex, dementia severity, and IRI-EC scores. Lower scores on the IRI-EC correlated with higher scores on the SBQ-AGG-but not with higher scores on the SBQ-RB-across the combined group of participants (P = 0.02) after controlling for covariates of age, sex, dementia severity, and IRI-PT scores.

Conclusion: Our results suggest that socioemotional dysfunction relates to antisocial behaviors in individuals with bvFTD, but that the mechanisms leading to aggressive and rule-breaking behaviors are differentiable, providing meaningful implications for distinct approaches to treatment and prevention.