Clinical Profile of Bipolar Patients with Seasonal Pattern: a systematic review

Abstract

ABSTRACT Introduction: Bipolar disorder(BD) is mainly characterised by (hypo)manic and depressive episodes, with recent studies showing that up to 25% of BD patients present a seasonal pattern(SP). The aim of this review is to uncover if BD patients with SP display a distinct clinical profile. Methods: A systematic review was conducted on the clinical presentation of BD patients with and without SP, by querying PubMed and Web of Science. Results: Sixteen papers were included, involving more than 13,000 BD patients. Some of the studied outcomes didn't present significant differences between groups but, overall, BD patients with SP were found to have an earlier age of onset of the disorder, be predominantly BD type-II, have an higher recurrence of mood episodes and have a more severe form of the disease, comparing with BD patients without SP. Limitations: Only two search engines and articles in English were queried, some studies present small sample sizes and some limitations of the methodology applied to evaluate seasonality. Conclusion: Even though it's soon to present any definitive conclusion, this review highlights some evidence that point a distinct clinical profile in BD patients with SP.