Correlates of long duration of untreated illness (DUI) in patients with bipolar disorder: results of an observational study

Background: Despite a high number of studies investigating the correlation between long Duration of Untreated Illness (DUI) and poor course of Bipolar Disorder (BD), the results concerning the impact of DUI on some specific factors, such as suicidality and medical comorbidities, are still inconsistent. This cross-sectional observational study aimed at analyzing potential socio-demographic and clinical correlates of long DUI in a large cohort of real-world, well-characterized BD patients. Methods: The socio-demographic and clinical characteristics of 897 patients with BD were collected. The sample was divided for analysis in two groups (short DUI vs long DUI) according to a DUI cutoff of 2 years. Comparisons were performed using χ2 tests for categorical variables and the Kruskal-Wallis test for continuous variables. Logistic regression (LogReg) was used to identify explanatory variables associated with DUI (dependent variable). Results: Six-hundred and sixty patients (75.5%) presented long DUI (> 2 years) and mean DUI was 15.7 years. The LogReg analysis confirmed the association of long DUI with bipolar II disorder (p: 0.016), lower age at onset (p < 0.001), depressive predominant polarity (p: 0.018), depressive polarity onset (p < 0.001), longer duration of illness (p < 0.001), lifetime suicide attempts (p: 0.045) and current medical comorbidities (p: 0.019). Conclusions: The present study confirms the association between long DUI and higher risk of suicide attempts in patients with BD. Moreover, an association between long DUI and higher rates of medical conditions has been found.