Impact of personality status on the outcomes and cost of cognitive–behavioural therapy for health anxiety

BACKGROUND: Health anxiety, hypochondriasis and personality disturbance commonly coexist. The impact of personality status was assessed in a secondary analysis of a randomised controlled trial (RCT). AIMS: To test the impact of personality status using ICD-11 criteria on the clinical and cost outcomes of treatment with cognitive-behavioural therapy for health anxiety (CBT-HA) and standard care over 2 years. METHOD: Personality dysfunction was assessed at baseline in 444 patients before randomisation and independent assessment of costs and outcomes made on four occasions over 2 years. RESULTS: In total, 381 patients (86%) had some personality dysfunction with 184 (41%) satisfying the ICD criteria for personality disorder. Those with no personality dysfunction showed no treatment differences (P = 0.90) and worse social function with CBT-HA compared with standard care (P<0.03) whereas all other personality groups showed greater improvement with CBT-HA maintained over 2 years (P<0.001). Less benefit was shown in those with more severe personality disorder (P<0.05). Costs were less with CBT-HA except for non-significant greater differences in those with moderate or severe personality disorder. CONCLUSIONS: The results contradict the hypothesis that personality disorder impairs response to CBT in health anxiety in both the short and medium term