Longer duration of untreated bipolar disorder (DUB) can lead to a prolonged exposure to inflammatory and neurodegenerative processes, that are believed to underlie etiopathogenesis of bipolar affective disorder (BAD), and thus cause a more severe course of illness as well as difficulties in the maintenance of remission.

The aim was to determine the relationship between DUB and socio-demographic characteristics, along with clinical characteristics related to the course of illness, applied psychopharmacotherapy and the ability to maintain an adequate remission over 24 months period following hospital treatment.

The study used retrospective design and included patients with BAD (n = 127), hospitalized between 2006 and 2010. We acquired data on socio-demographic and clinical characteristics, previous treatment and the information on posthospital period between 0 and 24 months.

The average DUB was 130.59 ± 108.44 months. Patients with longer DUB presented with higher number of mood episodes of BAP, higher number of inpatient treatments, and required a significantly higher dose of lithium in the remission period. Female patients and those with metabolic syndrome more frequently failed to maintain remission for more than 24 months.

Interventions for monitoring of DUB, its diminishing duration, early detection and recognition, and timely treatment, would be useful for fewer relapses and therefore a better course and outcome of BAP. Furthermore, the results of the study strongly imply that a systematic, longitudinal monitoring of the course of illness and potential inflammatory, endocrine and metabolic markers that underlie its systemic nature is recommended.