Altered magnetic resonance white-matter T1 values in patients with affective disorder.

The MRI T1 proton relaxation values were assessed in 14 patients with bipolar affective disorder and 10 with a unipolar disorder and a matched normal control group. The T1 values in the frontal white matter of patients significantly exceeded those of the controls. This difference was accounted for by an increase in T1 values in the frontal white matter of unipolar patients: the values for bipolar patients alone did not differ from those for controls. These preliminary findings support a hypothesis of frontal lobe dysfunction mediating pathological changes in mood.