Hospitalizações por perturbação bipolar e perturbações do uso de substâncias: Um estudo nacional retrospetivo entre 2008 e 2015

Abstract

Background: Bipolar Disorder (BD) is a severe and chronic mental disorder often complicated by co-occurring substance use disorders (SUD). This study aimed to assess the prevalence of registered SUD among BD hospitalization episodes and to analyze its association with hospitalization outcomes. Methods: We performed a retrospective observational study using a nationwide hospitalization database containing all hospitalizations registered in Portuguese public hospitals from 2008 to 2015. Hospitalizations with a primary or secondary diagnosis of BD were selected based on ICD-9-CM codes of diagnosis 296.0, 296.1, 296.4, 296.5, 296.6, 296.7, and 296.8. Results: Of 22158 inpatient episodes with BD as a primary diagnosis, SUD was registered in 11.3% of episodes, with alcohol use disorder being the most prevalent (5.8%). A non-linear increase in the number of hospitalizations throughout the study period was found. Episodes with a concomitant register of SUD were associated with younger (44.1 ± 12.5 years old) and male patients (56.6%), shorter length of stay (LoS) (15.0 (8.0;24.0) days), higher Charlson Comorbidity Index (CCI) (0.24 ± 0.76), and with higher rates of attention-deficit, conduct, and disruptive behavior disorders, personality disorders, and suicide and intentional self-inflicted injury, compared to those without this comorbidity. Limitations: Limitations include the use of a sample that exclusively contains inpatients who were treated in public hospitals and the use of data registered for administrative reasons rather than research purposes. Conclusions: In this Portuguese nationwide study, comorbid SUD increased non-linearly and had a measurable impact on BD hospitalization outcomes. Timely detection and management of SUD among BD patients may likely prevent the high burden.