title: Changes in dopamine D2-receptor binding are associated to symptom reduction after psychotherapy in social anxiety disorder.
abstract: The dopamine system has been suggested to play a role in social anxiety disorder (SAD), partly based on molecular imaging studies showing reduced levels of striatal dopaminergic markers in patients compared with control subjects. However, the dopamine system has not been examined in frontal and limbic brain regions proposed to be central in the pathophysiology of SAD. In the present study, we hypothesized that extrastriatal dopamine D2-receptor (D2-R) levels measured using positron emission tomography (PET) would predict symptom reduction after cognitive behavior therapy (CBT). Nine SAD patients were examined using high-resolution PET and the high-affinity D2-R antagonist radioligand [(11)C]FLB 457, before and after 15 weeks of CBT. Symptom levels were assessed using the anxiety subscale of Liebowitz Social Anxiety Scale (LSAS(anx)). At posttreatment, there was a statistically significant reduction of social anxiety symptoms (P<0.005). Using a repeated measures analysis of covariance, significant effects for time and time × LSAS(anx) change on D2-R-binding potential (BP(ND)) were shown (P<0.05). In a subsequent region-by-region analysis, negative correlations between change in D2-R BP(ND) and LSAS(anx) change were found for medial prefrontal cortex and hippocampus (P<0.05). This is the first study to report a direct relationship between symptom change after psychological treatment and a marker of brain neurotransmission. Using an intra-individual comparison design, the study supports a role for the dopamine system in cortical and limbic brain regions in the pathophysiology of SAD.
authors: Department of Clinical Neuroscience, Division of Psychiatry, Karolinska Institutet, Stockholm, Sweden. simon.cervenka@ki.se
authors: S
authors: S
authors: Cervenka
authors: E
authors: E
authors: Hedman
authors: Y
authors: Y
authors: Ikoma
authors: D Radu
authors: DR
authors: Djurfeldt
authors: C
authors: C
authors: Rück
authors: C
authors: C
authors: Halldin
authors: N
authors: N
authors: Lindefors
mesh_terms: D000328:Adult; D002250:Carbon Radioisotopes; D015928:Cognitive Behavioral Therapy; D003342:Corpus Striatum / Q000000981:diagnostic imaging; D018492:Dopamine Antagonists; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging; D006624:Hippocampus / Q000000981:diagnostic imaging; D006801:Humans; D020407:Internet; D008032:Limbic System / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory; D010698:Phobic Disorders / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging; D011615:Psychotherapy, Group; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012457:Salicylamides; D013813:Therapy, Computer-Assisted
chemical_list: D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D012457:Salicylamides; C065065:FLB 457