T2-weighted image hyperintensities in major depression: focus on the basal ganglia

A major focus of attention in structural brain-imaging research in major depression is the increased prevalence of T2-weighted image 'hyperintensities' (T2-WIH). Our aims in this study were to characterize the distribution and magnetic resonance imaging (MRI) presentation of brain hyperintensities in major depression patients compared to healthy control subjects and to explore the association between the presence of T2-WIH and measures of clinical and cognitive state. Thirty-seven patients suffering from major depression and 27 age- and sex-matched healthy controls underwent brain MRI and were evaluated by the Hamilton Rating Scale for Depression, the Mini Mental State Examination and the Haschinsky Ischaemia Index. T2-WIH (at least one) were found in 26 out of 37 major depression patients and 7 out of 27 controls (p=0.0001). The number of brain T2-WIH was significantly and positively correlated with age in depressed (p=0.001) but not in healthy subjects. Mean volume of T2-WIH was significantly greater (p=0.004) in depressed subjects. In the control group T2-WIH were exclusively located in the supratentorial hemispheral white matter while in the depressed group T2-WIH were also found in basal ganglia, temporal lobe, cerebellum and brainstem. More (52 vs. 20%; p=0.018) T2-WIH were demonstrable on T1 in depressed subjects. Depressed patients with T2-WIH in basal ganglia were clearly the most severely depressed and cognitively impaired subjects, and may constitute a clinically distinct subgroup within major depression.