Pharmacopsychiatry 2007; 40 - A027
DOI: 10.1055/s-2007-991702

Reduced thalamic serotonin transporter availability in patients with major depression

A Knobel 1, A Batra 2, M Reimold 3, MN Smolka 4, A Zimmer 4, K Mann 4, C Solbach 5, G Reischl 5, F Schwärzler 2, G Gründer 6, HJ Machulla 5, R Bares 3, A Heinz 1
  • 1Department of Psychiatry, Charité University Medical Center, CCM, Berlin, Germany
  • 2Department of Psychiatry, University of Tübingen, Germany
  • 3Department of Nuclear Medicine, University of Tübingen, Germany
  • 4Department for Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Mannheim, Germany, University of Heidelberg, Germany
  • 5Department of Radiopharmacy and PET Center, University of Tübingen, Germany
  • 6Department of Psychiatry and Psychopharmacy, RWTH Aachen University, Germany

Background: Serotonergic dysfunction may contribute to negative mood states in affective disorders. Some in vivo imaging studies showed reduced availability of serotonin transporters (5-HTT) in the brainstem and thalamus of patients with major depression. We tested the hypothesis that 5-HTT availability is reduced in unmedicated unipolar patients with major depression compared with healthy control subjects matched for gender, age, genotype and smoking status. Methods: 5-HTT availability was measured in vivo with positron emission tomography and [11C]DASB in the midbrain, thalamus and amygdala. DASB binding was correlated with the severity of depression (Beck's Depression Inventory). Results: Patients with major depression displayed reduced 5-HTT availability in the thalamus (P=0.005) compared with healthy control subjects individually matched for age, smoking status, 5-HTT genotype and gender. In patients, low serotonin transporter availability correlated with severity of depression (BDI). However, this correlation did not survive correction for multiple testing. Conclusions: These results support the hypothesis that central serotonergic dysfunction is associated with negative mood states in affective disorders. In the thalamus, a low serotonin reuptake capacity may interfere with thalamic control of cortical excitability.