Prevalence of personality disorders using two diagnostic systems in psychiatric outpatients in Shanghai, China: a comparison of uni-axial and multi-axial formulation

To compare multi-axial (DSM-IV) with uni-axial diagnostic system (CCMD-3, Chinese Classification and Diagnostic Criteria of Mental Disorders) as diagnostic methods to determine the prevalence of personality disorders (PDs) in Chinese psychiatric outpatients. 3,075 outpatients were randomly sampled from clinical settings in China. CCMD-3 PDs were evaluated as per routine psychiatric practice. DSM-IV PDs were assessed using both self-reported questionnaire and structured clinical interview. The prevalence estimate for any type of PD in the total sample is 31.93% as reflected in the DSM-IV. This figure is nearly 110 times as large as the prevalence estimate for the CCMD-3. Only 9 outpatients were diagnosed with PD based on the CCMD-3. Amongst the 10 forms of DSM-IV PDs, avoidant (8.1%), obsessive-compulsive (7.6%), paranoid (6.0%), and borderline (5.8%) PDs were the most prevalent subtypes. This study found that PDs are commonly associated with the following: (i) the younger aged; (ii) single marital status; (iii) those who were not raised by their parents; (iv) introverted personalities; (v) first-time seekers of psycho-counseling treatment; and (vi) patients with co-morbid mood or anxiety disorders. PDs are easily overlooked when the diagnosis is made based on the CCMD-3 uni-axial diagnostic system. However, it was found that personality pathology is common in the Chinese psychiatric community when using the DSM-IV classification system. Existing evidence suggest, at least indirectly, that there are important benefits of moving towards a multi-axial diagnostic approach in psychiatric practice.