Anxiety, depression, and quality of life among subgroups of individuals with acquired brain injury: The role of anxiety sensitivity and experiential avoidance.

OBJECTIVES The objectives of this observational cohort study were to 1) cluster individuals with acquired brain injury (ABI) into subgroups according to their level of anxiety sensitivity (AS) and experiential avoidance (EA), and 2) compare subgroups with respect to anxiety, depression, and quality of life (QoL). METHODS Individuals were recruited from an ABI outpatient clinic in Ontario, Canada and completed comprehensive psychosocial questionnaires. A two-step cluster analysis was performed to identify unique subgroups based on the clustering variables Anxiety Sensitivity Index (ASI) and Acceptance and Action Questionnaire (AAQ) which measure AS and EA, respectively. Clinical outcome measures were compared between clusters using multivariate analysis of variance: Generalized Anxiety Disorder 7 item (anxiety); Patient Health Questionnaire-9 (depression), and EQ-5D overall health item (QoL). RESULTS Among 86 participants included for analysis (mean age 47.1±14.2 years, 54.7% female), three unique clusters were produced. ASI and AAQ were significantly different among all groups (p < 0.001). Cluster 1 (n = 26) had the lowest levels of AS and EA whereas Cluster 3 (n = 24) had the highest levels of AS and EA; Cluster 2 (n = 36) had moderate levels of AS and EA. There was no significant difference between groups in age, gender, time since injury, or Glasgow Coma Scale scores. Cluster 3 had significantly higher anxiety and depression scores than Cluster 1 and 2 (p < 0.001 for all). Further, Cluster 2 had significantly higher anxiety and depression scores than Cluster 1 (p < 0.001 for all). There was no significant difference in EQ-5D scores between Clusters 1 and 2 or Cluster 2 and 3; however, Cluster 3 scored significantly lower on EQ-5D than Cluster 1 (p = 0.032). CONCLUSIONS There exists a subgroup of individuals with ABI that have high levels of AS and EA; this was associated with greater symptoms of anxiety and depression, and poorer QoL. Interventions to address AS and EA may improve mood and QoL in this population.