Hippocampal Structural MRI Abnormalities in Euthymic Bipolar I Disorder

Louise Emsell^1,2, Camilla Langan¹, Helen Casey¹, Sarah Hehir¹, Rory Nannery¹, Wil Van Der Putten¹, Peter McCarthy¹, Colm McDonald¹, Dara M. Cannon¹

This study sought to identify trait related structural MRI abnormalities in the hippocampus in 60 prospectively confirmed euthymic bipolar I disorder patients compared to 60 individually age and gender matched controls. Hippocampi were traced manually using predefined anatomical boundaries. A repeated measures ANCOVA analysis including diagnosis, gender and hemisphere with age and total intracranial volume as covariates demonstrated subtle reductions in the hippocampal volume of patients bilaterally (p=0.046). There were no other significant findings including correlations within patients related to illness duration or medication status.