Prevalence of Comorbid Personality Disorder in Psychotic and Non-psychotic Disorders

Introduction: The burden of personality disorders (PDs) in China is large and the focus on mental health services is increasing. However, there is a lack of sufficient evidence regarding the prevalence of comorbid PD in psychotic and non-psychotic disorders, and whether PDs have different distributions. We aimed to investigate the PD comorbidity distribution pattern between psychotic and non-psychotic disorders using a clinical population-based study.Materials and Methods: We conducted a cross-sectional study of 1,497 patients in Shanghai. PDs were screened using the Personality Diagnostic Questionnaire Fourth Edition Plus (PDQ-4+). All patients were interviewed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) Axis II (SCID-II). We compared the differences in PD comorbidities classified as the 10 types of PDs in the DSM-IV, in 531 patients with psychosis and 966 patients with non-psychotic disorders.Results: More than one-third (37%) of patients with psychotic disorders met the criteria of at least one PD. Approximately half (46%) of patients with non-psychotic disorders met the criteria of at least one PD. Patients with non-psychotic disorders were more likely to meet the criteria of borderline (chi(2) = 20.154, p < 0.001) and obsessive-compulsive PD (chi(2) = 21.164, p < 0.001) diagnoses compared to those with psychotic disorders. In contrast, patients with psychotic disorders were more likely to meet the criteria of paranoid (chi(2) = 11.144, p = 0.001) and schizotypal PD (chi(2) = 14.004, p < 0.001) diagnoses than those with non-psychotic disorders.Discussion: PD comorbidity is common and comorbidity distribution pattern is varied in patients with psychotic and non-psychotic disorders, implicating the development of specific strategies that could screen and assess PDs in psychiatric clinical practice.

Automated summary

The burden of personality disorders in China is significant, with common comorbidities in both psychotic and non-psychotic disorders. However, the distribution patterns of PDs differ between the two types of disorders, suggesting the need for specific strategies in psychiatric clinical practice to address these differences.