A neuroendocrine perspective on anxiety-related behaviour in humans: focus on testosterone and oxytocin.

Abstract

Accumulating evidence indicates that the steroid hormone testosterone and the neuropeptide oxytocin may have anxiolytic effects in humans, albeit via different mechanisms. In animals, the anxiolytic properties of testosterone and oxytocin are relatively well-established. In this review, findings of the anxiolytic effects of testosterone and oxytocin in animals are first discussed as well as the possible neurobiological mechanisms by which these hormones exert their effects. Then, a transition to human studies is made and finally the potential of testosterone and oxytocin for the treatment of Social Anxiety Disorder is addressed. From the evidence reviewed here it can be concluded that testosterone promotes active dealing with threat. It enhances attention to threatening social stimuli in an approach-related manner and reduces fear in (socially) challenging situations. Oxytocin on the other hand can have soothing effects, because it reduces background anxiety and acts to re-establish homeostasis in the face of threat. It promotes the processing of social cues, in particular positive social cues. Similar to testosterone, oxytocin enhances social approach behaviour but in an affiliative rather than challenge-orientated manner. Neurobiological pathways involving the amygdala seem implicated in these effects.