Functional brain imaging and pharmacotherapy in social phobia: Single photon emission computed tomography before and after treatment with the selective serotonin reuptake inhibitor citalopram

1. Despite increased understanding of the prevalence and pharmacotherapy of social phobia (or social anxiety disorder), the neurobiology of the disord er is little understood. 2. Little data exists on the effect of pharmacotherapeutic intervention on regional cerebral blood flow (rCBF) in this disorder. Patients (n=15) who m et DSM-IV diagnostic criteria for social phobia were subjected to single ph oton emission computed tomography (SPECT) with technetium-99m hexamethylpro pylene amine oxime (Tc-99m HMPAO) before and after an eight-week trial of p harmacotherapy with the selective serotonin reuptake inhibitor (SSRI) cital opram. 3. Pharmacotherapy led to significantly reduced activity in the anterior an d lateral part of the left temporal cortex; the anterior, lateral and poste rior part of the left mid frontal cortex; and the left cingulum. 4. Despite the small sample size, medication non-responders (n=6) had highe r activity at baseline in the anterior and lateral part of the left tempora l cortex and the lateral part of the left mid frontal regions compared with responders (n=9). These data from this exploratory study are consistent wi th work suggesting that the anxiety disorders share certain mediating neuro circuitry, although activity in other brain regions may differ. 5. Further research is necessary to determine the neurobiological underpinn ings of social phobia.