Seasonality Patterns in Bipolar Disorder: Associations With Clinical Phenotypes and Treatment-Related Outcomes

Area of Science:

• Psychiatry and Behavioral Sciences
• Mood Disorders Research
• Chronobiology

Background:

• Approximately 25% of patients with bipolar disorder (BD) experience mood episodes with a seasonal pattern.
• Understanding these seasonal patterns is crucial for personalized treatment approaches.

Purpose of the Study:

• To investigate the associations between specific seasonality patterns in BD and clinical phenotypes.
• To examine the relationship between seasonality patterns and treatment-related outcomes, including medication exposure and response to mood stabilizers.

Main Methods:

• Utilized data from the Mayo Clinic Bipolar Disorder Biobank, including 1702 patients with available seasonality data.
• Categorized participants with seasonality into four groups: fall/winter depression, spring/summer (hypo)mania, biphasic, and equinoctial seasonality.
• Employed regression models to analyze the association of seasonality patterns with clinical features and treatment outcomes.

Main Results:

• 44.6% of patients reported seasonal mood episodes, with specific patterns linked to distinct clinical characteristics.
• Fall/winter depression was associated with increased antidepressant use, psychotropic exposure, and poorer response to mood stabilizers.
• Spring/summer (hypo)mania showed a negative association with rapid cycling and antidepressant use, while equinoctial seasonality was linked to a history of psychosis.

Conclusions:

• Seasonality in BD is associated with specific clinical features and treatment outcomes, suggesting distinct illness subtypes.
• Fall/winter depression patterns may indicate a more complex and treatment-resistant course of BD.
• Highlights the need for nuanced classification of BD seasonality beyond a simple seasonal/non-seasonal dichotomy to improve illness management.