The Koukopoulos mixed depression rating scale (KMDRS) and the assessment of mixed symptoms during the perinatal period

Background: Mixed symptoms in depression may underlie bipolar diathesis rather than unipolarity. Uncovering mixed depression (MxD) is crucial for appropriate management, especially in the perinatal period, as it may affect treatment planning and impact future child development. We used a scale specific for identifying MxD and tested its validity in pregnant and postpartum women with depression. Methods: Women developing a major depressive episode (MDE) during their perinatal period extending from pregnancy to one year postpartum from November-2012 through June-2019 were assessed with BPRS-18, EPDS, CGI-S, GAF, HAM-A, HAM-D, Koukopoulos' Mixed Depression Rating Scale (KMDRS), TEMPS, and YMRS. They were classified, based on KMDRS criteria, as with mixed (MxD) or without (nonMxD) mixed symptoms. We conducted ROC analysis and performed factor analysis of the KMDRS. Results: Of 45 included, MxD (N = 19) were biased towards diagnosis of bipolar disorder and nonMxD (N = 26) towards major depressive disorder. Other sociodemographic variables did not differ significantly between MxD and nonMxD. MxD scored higher on total YMRS, BPRS, and KMDRS, and on KMDRS-6 Subjective Feelings of Irritability and KMDRS-12 Suicidal Impulsiveness items. The KMDRS correlated in the entire sample, in MxD and nonMxD, with the YMRS and the BPRS, while correlating with the HAM-D in nonMxD only. The KMDRS showed acceptable AUC distribution, with a 68% sensitivity and 58% specificity. Best-fit was three-factor-structure, explaining 54.66% of cumulative variance. Limitations: Small sample and cross-sectional design. Conclusions: The KMDRS is fit for investigating MxD along with the YMRS and the BPRS in perinatal women with a MDE.