Personality difficulties and response to community-based psychological treatment for anxiety and depression.

Background: Previous research suggests that comorbid personality disorder may be associated with a less favourable treatment outcome for individuals with depression and anxiety disorder. However, little is known about whether personality difficulties are associated with treatment outcomes within Improving Access to Psychological Therapies (IAPT) services-the largest platform for treating depression and anxiety in England, UK. Secondary aims were to investigate i) whether individual personality difficulties are associated with treatment outcome and ii) whether findings are moderated by treatment type.
Methods: The sample included 3,689 adults who accessed community-based psychological treatment (cognitive behavioural therapy, emotional skills training, or other psychological therapy) for depression and/or anxiety disorder. Associations between personality difficulties (assessed with the Standardised Assessment of Personality-Abbreviated Scale (SAPAS)) and treatment outcomes (recovery and reliable improvement in depression/anxiety symptom scores, assessed using questionnaire-based measures) were investigated using logistic/linear regression.
Results: Personality difficulties were associated with a reduced likelihood of recovery (adjusted OR per unit increase on SAPAS: depression=0.87, 95%CI 0.84, 0.91; anxiety=0.86, 95%CI 0.82, 0.90) and reliable improvement (adjusted OR per unit increase on SAPAS: depression=0.88, 95%CI 0.84, 0.92; anxiety=0.85, 95%CI 0.82, 0.89). Those with three or more difficulties were over 30% less likely to recover/reliably improve.
Limitations: Personality difficulties data were collected via self-report and were not available for all participants.
Conclusion: Patients with personality difficulties have a less favourable response to psychological treatment for depression/anxiety disorder. If replicated, the findings highlight a major challenge to the way community-based psychological therapy services in England (IAPT services) are presently constituted.
(Copyright © 2020. Published by Elsevier B.V.)