DSM-III-R personality disorders in outpatients with non-bipolar depression: the frequency in a sample of Japanese and the relationship to the 4-month outcome under adequate antidepressant therapy.

We investigated the frequency of personality disorders (PDs) and the relationship between the presence of PD and the 4-month outcome of depression under adequate antidepressant therapy in a Japanese sample of 96 outpatients with non-bipolar major depression. The diagnosis of PD was made using a structured interview method (the Structured Clinical Interview for DSM-III-R Personality Disorders) and after severe depressive symptoms were reduced. Any one kind of PD was found in 54.2% of the sample. The most frequent was avoidant (35.4%), obsessive-compulsive (22.9%), narcisstic (18.8%), and dependent (16.7%) PDs. The frequencies of these PDs in our study, except narcisstic PD, were about the same as those reported in previous studies with a matched setting for the PD diagnosis. Compared with patients without PD, a worse outcome was found in patients with PD, especially patients with multiple PDs from multiple PD clusters. There was no evidence that a specific PD or PD cluster especially worsens the outcome of depression.