Platelet [³H]-imipramine binding and leukoencephalopathy in geriatric depression

We examined the relationship between platelet [³H]-imipramine binding and leukoencephalopathy as assessed by 1.5 Tesla Magnetic Resonance Imaging (MRI) in 21 elderly depressed patients who satisfied DSM-III criteria for major depression. Both drug-free platelet [³H]-imipramine binding and brain MRI studies were obtained during the same episode of depression. Our findings show a significant inverse relationship between frequency of subcortical hyperintensity (SCH) and the number (B_max of platelet [³H]-imipramine binding sites. Patients with B_max less than 850 fmol/mg protein had significantly larger SCH compared with patients with a higher B_max. These data provide further support to the potential use of platelet [³H]-imipramine binding studies and brain MR imaging as diagnostic adjuncts in geriatric depression and suggest, moreover, that these two biological markers may be linked in geriatric patients with depression.