Factors Influencing the Number of Relapse in Patients with Bipolar I Disorder

Abstract

Background: Type I bipolar disorder is a chronic mental illness with a recurrent nature. Objectives: This study was done to identify risk factors for relapse in patients with type I bipolar disorder using Poisson regression. Methods: In this retrospective cohort study, data were collected from 331 bipolar type I patients admitted to the largest and the only psychiatric hospital in West of Iran, Kermanshah. Poisson regression was used to identify risk factors for the relapse numbers in STATA software. Results: One hundred sixty six of 331 patients (50.2%) were men. Mean and standard deviation of relapse rates in males and females were 2.93 ± 0.16 and 2.93 ± 0.15, respectively. In multivariate analysis, the results showed that with increasing age of disease onset (RR = 0.98, 95% CI :(0.97 -0.99)) and adherence to medication (RR = 0.86, 95% CI :(0.75-0.98)), the relapse rate ratio decreased, and being divorced or widowed (RR = 1.20,95% CI :( 1.01-1.45)), cigarette smoking (RR = 1.28, 95% CI: (1.52-1.09)), and birth season of winter (RR = 1.18, 95% CI: (1.00-1.41)) increased the rate ratio of relapse. Conclusions: The results of this study showed that the frequency of relapse was lower in bipolar patients younger at the time of disease onset, cigarette smokers, divorced or widowed patients, and patients with no treatment adherent. It is necessary to prevent or reduce the likelihood of relapse, especially in patients who do not have therapeutic adherence through educational and therapeutic measurements.