Quantification of brain proton longitudinal relaxation (T1 ) in lithium-treated and lithium-naïve patients with bipolar disorder in comparison to healthy controls.

The higher T1 values observed in the patients with bipolar disorder may reflect abnormal tissue microstructure. Whilst the precise mechanism remains unknown, these findings may have a basis in differences in myelination, macromolecular content, iron and water content between patients and controls.