Amphetamine misuse and social phobia

The response to sulpiride in social anxiety disorder: D2 receptor function

Some previous studies have suggested that patients with social anxiety disorder (SAD) have a hypoactive central dopaminergic system. Supporting this there have been reports from neuroimaging studies of reduced striatal D2 receptor binding in subjects with SAD. The aim of this study was to investigate D2 receptor sensitivity in patients with SAD compared with a group of matched, healthy controls using a neuroendocrine challenge with the selective D2 antagonist, sulpiride. D2 receptor function was assessed in 23 subjects with generalized SAD and 23 matched, healthy controls using a challenge with 400 mg of a selective D2 antagonist, sulpiride in a randomized, placebo-controlled, crossover design. Response to sulpiride was measured by the change in prolactin level and changes in self-rated measures of social anxiety, mood and the ability to experience pleasure. There was no significant difference in prolactin response to sulpiride between the two groups. Sulpiride resulted in no effect in either the SAD or healthy control group on measures of social anxiety, mood or the ability to experience pleasure. Contrary to our hypothesis, in this study we found no evidence of reduced D2 receptor function in subjects with SAD compared with healthy controls.

The pharmacology of anxiety

Understanding the neurochemistry of anxiety is of fundamental importance in the development and use of novel anxiolytics. Through measuring peripheral markers of brain biochemistry, direct pharmacological challenges and brain neuroimaging techniques our understanding of this field has increased substantially in the past few decades. We review the four most studied neurotransmitter systems with respect to in anxiety disorders: gamma amino-butyric acid, serotonin, noradrenaline and dopamine. We have focussed upon clinical studies to highlight the current techniques used to determine brain neurochemistry in vivo. Future research in this field will greatly benefit from recent advances in neuroimaging techniques and the discovery of novel ligands targeting specific receptors.

O papel do sistema dopaminérgico na fobia social

Os autores descrevem o papel do sistema dopaminérgico na fobia social. Evidências que indicam disfunção dopaminérgica são descritas, e o papel da dopamina como um regulador da atividade social é discutido.