Cerebral white matter lesions in bipolar affective disorder: relationship to outcome

Background Twenty percent of patients with bipolar affective disorder suffer an illness that responds inadequately to treatment and has a poor outcome. Many patients, but not all, with bipolar disorder show white matter abnormalities on T-2-weighted magnetic resonance imaging (MRI). Aims To explore the hypothesis that white matter abnormalities on MRI are seen more frequently in subjects whose illness has a poor outcome compared with those with a good outcome or controls. Method Two groups of age-and gender-matched patients with bipolar disorder (14 with a good outcome and 15 with a poor outcome) and 15 controls, aged 20-65 years, were studied. Axial T-2-weighted MRI scans were examined for the presence and severity of white matter abnormalities. Results Significantly more poor outcome group members had deep subcortical punctate, but not periventricular, white matter hyperintensities than the good outcome group (P=0.035) or controls (P=0.003) and these abnormalities were of greater severity (P=0.030 and P < 0.014, respectively). Conclusions Subcortical white matter lesions are associated with poor outcome bipolar disorder.