Midline brain abnormalities in established bipolar affective disorder

BackgroundMorphologic changes of cortico-limbic regions have been reported in bipolar disorder, but it remains unclear whether midline brain abnormalities relevant to cortico-limbic connectivity are also present.MethodsWe used magnetic resonance imaging to investigate the size of the adhesio interthalamica (AI) and cavum septi pellucidi (CSP), as well as third ventricular volume, in 26 patients with bipolar I disorder and 24 matched controls.ResultsCSP length and prevalence of a large CSP did not differ between the groups, but bipolar patients had significantly shorter AI and larger third ventricles compared to controls.LimitationsA comprehensive investigation of medication effects was not possible due to incomplete medication data.ConclusionsThese findings implicate a role for the AI and connected brain regions in the neurobiology of bipolar disorder.