Objective: The purpose of this investigation was to identify distinctive clinical correlates of psychotic major depression (PMD) as compared with non-psychotic major depression (NPMD) in a large cohort of Korean patients with major depressive disorder (MDD).
Methods: We recruited 966 MDD patients of age over 18 years from the Clinical Research Center for Depression of South Korea (CRESCEND) study. Diagnoses of PMD (n=24) and NPMD (n=942) were made with the DSM-IV definitions and confirmed with SCID. Psychometric scales were used to assess overall psychiatric symptoms (BPRS), depression (HAMD), anxiety (HAMA), global severity (CGI-S), suicidal ideation (SSI-Beck), functioning (SOFAS), and quality of life (WHOQOL-BREF). Using independent t-tests and χ(2) tests, we compared clinical characteristics of patients with PMD and NPMD. A binary logistic regression model was constructed to identify factors independently associated with increased likelihood of PMD.
Results: PMD subjects were characterized by a higher rate of inpatient enrollment, and higher scores on many items on BPRS (somatic concern, anxiety, emotional withdrawal, guilt feelings, tension, depression, suspiciousness, hallucination, motor retardation, blunted affect and excitement) global severity (CGI-s), and suicidal ideation (SSI-Beck). The explanatory factor model revealed that high levels of tension, excitement, and suicidal ideation were associated with increased likelihood of PMD.
Conclusion: Our findings partly support the view that PMD has its own distinctive clinical manifestation and course, and may be considered a diagnostic entity separate from NPMD.
Keywords: Diagnostic entity; Distinctive correlates; Psychotic major depression.