Personality disorders and the persistence of anxiety disorders in a nationally representative sample.

BACKGROUND: Among individuals with anxiety disorders, comorbid personality disorders (PDs) increase cross-sectional symptom severity and decrease functioning. Little is known, however, about how PDs influence the course of anxiety disorders over time. The purpose of this study was to examine the effect of PDs on the persistence of four anxiety disorders in a nationally representative sample in the United States.
METHODS: Two waves of data were collected on 34,653 participants, 3 years apart. At both waves, participants were evaluated for generalized anxiety disorder (GAD), social and specific phobias, and panic disorder. Predictors of persistence included all DSM-IV PDs. Control variables included demographics, comorbid PDs, age at onset of the anxiety disorder, number of prior episodes, duration of the current episode, treatment history, and cardinal symptoms of exclusionary diagnoses for each anxiety disorder.
RESULTS: Any PD, two or more PDs, borderline PD, schizotypal PD, mean number of PD criteria met, and mean number of PDs diagnosed predicted the persistence of all four anxiety disorders. Narcissistic PD predicted persistence of GAD and panic disorder. Schizoid and avoidant PDs also predicted persistence of GAD. Finally, avoidant PD predicted persistence of social phobia. Particular patterns of cross-cluster PD comorbidity were strong predictors of the persistence of individual anxiety disorders as well.
CONCLUSIONS: In this national sample, a variety of PDs robustly predicted the persistence of anxiety disorders over 3 years, consistent with the results of recent prospective clinical studies. Personality psychopathology should be assessed and addressed in treatment for all patients with anxiety disorders.