Objective: Bipolar disorder displays a spectrum of manifestations, including manic, hypomanic, depressive, mixed, psychotic, and atypical episodes, contributing to its chronic nature and association with heightened suicide risk. Creating effective pharmacotherapy guidelines is crucial for managing bipolar disorder and reducing its prevalence. Treatment algorithms grounded in science have improved symptom management, but variations in recommended medications arise from research differences, healthcare policies, and cultural nuances globally. Methods: This study compares Korea's bipolar disorder treatment algorithm with guidelines from the UK, Australia, and an international association. The aim is to uncover disparities in key recommended medications and their underlying factors. Differences in CYP450 genotypes affecting drug metabolism contribute to distinct recommended medications. Variances also stem from diverse guideline development approaches-expert consensus versus metaanalysis results-forming the primary differences between Korea and other countries. Results: Discrepancies remain in international guidelines relying on meta-analyses due to timing and utilized studies. Drug approval speeds further impact medication selection. However, limited high-quality research results are the main cause of guideline variations, hampering consistent treatment conclusions. Conclusion: Korea's unique Delphi-based treatment algorithm stands out. To improve evidence-based recommendations, large-scale studies assessing bipolar disorder treatments for the Korean population are necessary. This foundation will ensure future recommendations are rooted in scientific evidence.