Challenges assessing personality disorders with the SCID-5-PD in psychiatric patients

Abstract Background: The SCID-5-PD is frequently used to diagnose personality disorders. The aim of this study is to compare the diagnostic outcomes of the SCID-5-PD with expert clinical assessment in an ICD-10 setting. Methods: A random sample of a total of 30 psychiatric in- and outpatients (mean age = 34 ± 16, 17 males and 13 females) went through a comprehensive clinical assessment conducted by experts. Subsequently, the patients were assessed with the SCID-5-PD by specifically trained novice raters. Results: 55% (n=11) of patients with clinical diagnosis within the schizophrenia spectrum were allocated one or more diagnoses of personality disorder according to the SCID-5-PD, primarily borderline personality disorder (n=6). In contrast, of all patients with a clinical diagnosis outside the schizophrenia spectrum, only one patient qualified for a diagnosis of personality disorder with the SCID-5-PD. Meanwhile, 70% (n=7) of patients with a clinical diagnosis of ICD-10 schizotypal disorder did not meet the criteria for this disorder when assessed with the SCID-5-PD. Conclusions: When considering a differential diagnosis within the schizophrenia spectrum, outcomes from the SCID-5-PD should be interpreted cautiously.