Axis II Comorbidity
This chapter is concerned with the comorbidity (or co-occurrence) among personality disorders. In the first half, we present the results from six large studies (at least 200 participants) that used structured diagnostic interviews to establish DSM-IV-TR personality disorder diagnoses. This includes present comorbidity data from two major epidemiological studies, the National Institute on Alcohol Abuse and Alcoholism (NIAAA) National Epidemiologic Survey on Alcohol and Related Conditions and the National Comorbidity Survey Replication. Next, we focus on two large clinical investigations of personality disorder comorbidity. Finally, we present data from two special population studies, including an English/Welsh forensic sample as well as a Norwegian twin sample. In the second half of this chapter, we explore both methodological and theoretical explanations of personality disorder comorbidity. We conclude with our own perspective of comorbidity as well as an overview of the implications of the current DSM-5 proposal on comorbidity.