The impact of obsessive compulsive personality disorder on cognitive behaviour therapy for obsessive compulsive disorder

Background: It is often suggested that in general, co-morbid personality disorders are likely to interfere with CBT based treatment of Axis I disorders, given that personality disorders are regarded as dispositional and are therefore considered less amenable to change than axis I psychiatric disorders.
Aims: The present study aimed to investigate the impact of co-occurring Obsessive-Compulsive Disorder (OCD) and Obsessive-Compulsive Personality Disorder (OCPD) on cognitivebehavioural treatment for OCD.
Method: 92 individuals with a diagnosis of OCD participated in this study. Data were drawn from measures taken at initial assessment and following cognitive behavioural treatment at a specialist treatment centre for anxiety disorders.
Results: At assessment, participants with OCD and OCPD had greater overall OCD symptom severity, as well as doubting, ordering and hoarding symptoms relative to those without OCPD, however participants with co-morbid OCD and OCPD demonstrated greater treatment gains in terms of OCD severity, checking and ordering than those without OCPD. Individuals with OCD and OCPD had higher levels of checking, ordering and overall OCD severity at initial assessment; however at post-treatment they had similar scores to those without OCPD.
Conclusion: The implications of these findings are discussed in the light of research on axis I and II co-morbidity and the impact of axis II disorders on treatment for axis I disorders.