Reduced Serotonin-1A Receptor Binding in Social Anxiety Disorder

• Published in: Biological psychiatry (1969) Vol. 61; no. 9; pp. 1081 - 1089
• Main Authors: Lanzenberger, Rupert R., Mitterhauser, Markus, Spindelegger, Christoph, Wadsak, Wolfgang, Klein, Nikolas, Mien, Leonhard-Key, Holik, Alexander, Attarbaschi, Trawat, Mossaheb, Nilufar, Sacher, Julia, Geiss-Granadia, Thomas, Kletter, Kurt, Kasper, Siegfried, Tauscher, Johannes
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.2007; Elsevier Science
• Subjects: 5-HT 1A; Adult; Adult and adolescent clinical studies; Affective disorders; anxiety; Anxiety disorders. Neuroses; Biological and medical sciences; Brain - diagnostic imaging; Brain Chemistry - physiology; Humans; Magnetic Resonance Imaging; Male; Medical sciences; PET; Phobia; Phobic Disorders - diagnostic imaging; Phobic Disorders - metabolism; Phobic Disorders - psychology; Piperazines; Positron-Emission Tomography; Psychiatric Status Rating Scales; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Pyridines; Receptor, Serotonin, 5-HT1A - metabolism; serotonin; Serotonin Antagonists; social phobia; STAI; anxiety; serotonin; Affective disorders; social phobia; 5-HT 1A; PET; STAI; Radionuclide study; Mood disorder; Affect affectivity; Serotonin; Social phobia; Anxiety disorder; Affective disorder; 5-HT1A Serotonine receptor; 5TAl; Neurotransmitter; 5-HT1A; Anxiety; Positron emission tomography; Emission tomography
• ISSN: 0006-3223; 1873-2402
• DOI: 10.1016/j.biopsych.2006.05.022

Results from studies in serotonin-1A (5-HT 1A) knockout mice and previous positron emission tomography (PET) studies in humans imply a role for 5-HT 1A receptors in normal state anxiety as well as in certain anxiety disorders. The objective of this study was to investigate 5-HT 1A receptor binding potential (BP) in social anxiety disorder (SAD). Using PET and [carbonyl- 11C]WAY-100635, we compared a homogeneous group of 12 unmedicated, male SAD patients with 18 healthy control subjects (HC). A multivariate ANOVA with all regional BP values as dependent variables, age and four radiochemical variables as covariates was performed. We found a significantly lower 5-HT 1A BP in several limbic and paralimbic areas but not in the hippocampus (p = .234) of SAD patients. The difference in 5-HT 1A binding was most significant in the amygdala (−21.4%; p = .003). There was also a more than 20% lower 5-HT 1A BP of SAD patients in the anterior cingulate cortex (p = .004), insula (p = .003), and dorsal raphe nuclei (p = .030). The lower 5-HT 1A binding in the amygdala and mesiofrontal areas of SAD patients is consistent with 1) preclinical findings of elevated anxiety in 5-HT 1A knockout mice, 2) a previous PET study in healthy volunteers showing an inverse correlation between 5-HT 1A BP and state anxiety, and 3) another human PET study in patients with panic disorder showing reduced 5-HT 1A binding, thus corroborating the potential validity of 5-HT 1A receptors as targets in the treatment of human anxiety disorders.