Salem H, et al. - Considering the earlier research indicating that among patients diagnosed with either bipolar disorder (BD) or borderline personality disorder (BPD), nearly 20% also met criteria for the other diagnosis, researchers investigated how co-occurring BPD and/or BPD features influence the course or outcome in patients with BD, utilizing the standardized Borderline Personality Questionnaire (BPQ). They included 714 adult patients with a primary diagnosis of BD per DSM-IV criteria and made them complete the BPQ within 72 hours of admission. As per the analysis, there was an association of the severity of certain BPD traits at baseline with the mood state and outcome measured by length of stay (LOS). They noted significantly higher mean scores on 7 of the 9 BPQ subscales among inpatients with BD who were admitted during acute depressive episodes compared with those admitted during acute manic episodes. Inpatients with BD with greater BPQ scores on 4 of the 9 BPQ subscales vs those with lower BPQ scores had significantly shorter LOS. In the machine learning model, 6 variables predicted the likelihood of 30-day readmission with high sensitivity (83%), specificity (77%), and area under the receiver operating characteristic curve of 86%.