title: The serotonin transporter in psychiatric disorders: insights from PET imaging.
abstract: Over the past 20 years, psychotropics affecting the serotonergic system have been used extensively in the treatment of psychiatric disorders. Molecular imaging, in particular PET, has allowed for elucidation of the essential contribution of the serotonin transporter to the pathophysiology of various psychiatric disorders and their treatment. We review studies that use PET to measure cerebral serotonin transporter activity in psychiatric disorders, focusing on major depressive disorder and antidepressant treatment. We also discuss opportunities and limitations in the application of this neuroimaging method in clinical practice. Although results from individual studies diverge, meta-analysis indicates a trend towards reduced serotonin transporter availability in patients with major depressive disorder. Inconsistencies in results might suggest symptom heterogeneity in major depressive disorder and might therefore be relevant for stratification of patients into clinical subsets. PET has enabled the elucidation of mechanisms of response to selective serotonin reuptake inhibitors (SSRIs) and hence provides a basis for rational pharmacological treatment of major depressive disorder. Such imaging studies have also suggested that the pattern of serotonin transporter binding before treatment might predict response to antidepressant treatment, which could potentially be clinically useful in the future. Additionally, this Review discusses PET studies investigating the serotonin transporter in anxiety, obsessive-compulsive disorder, and eating disorders. Few studies have shown changes in serotonin transporter activity in schizophrenia and attention deficit hyperactivity disorder. By showing the scarcity of data in these psychiatric disorders, we highlight the potential for further investigation in this field.
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
authors.forename: Marie
authors.initials: M
authors.lastname: Spies
authors.affiliation: Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Gitte M
authors.initials: GM
authors.lastname: Knudsen
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Lanzenberger
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria. Electronic address: sci-biolpsy@meduniwien.ac.at.
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kasper
mesh_terms: D000928:Antidepressive Agents / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000188:drug therapy / Q000503:physiopathology; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000188:drug therapy / Q000503:physiopathology; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000503:physiopathology; D001068:Feeding and Eating Disorders / Q000188:drug therapy / Q000503:physiopathology; D006801:Humans; D059906:Neuroimaging / Q000379:methods*; D009771:Obsessive-Compulsive Disorder / Q000188:drug therapy / Q000503:physiopathology; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D000928:Antidepressive Agents; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors