Objective: Research has found low concordance of personality disorder diagnoses made during depression versus after remission and made using patient versus collateral informants, but little is known about the reliability of personality disorder (PD) diagnoses made during depression using patient and collateral reports.
Method: A total of 168 patients were evaluated for PDs during depression and following response using patient and close informant reports. κ coefficients of inter-informant and test–retest reliability were calculated.
Results: After depression response, the proportion diagnosed with cluster A and C PDs fell by both patient and close informant report, and overall inter-informant reliability declined. Overall test–retest reliability did not differ between patients and informants.
Conclusion: Collateral informants do not improve the reliability of PD diagnoses made during depressive episodes.