MDMA enhances “mind reading” of positive emotions and impairs “mind reading” of negative emotions

In non-human mammals, the neuropeptide oxytocin is a key mediator of complex emotional and social behaviors, including attachment, social recognition, and aggression. Oxytocin reduces anxiety and impacts on fear conditioning and extinction. Recently, oxytocin administration in humans was shown to increase trust, suggesting involvement of the amygdala, a central component of the neurocircuitry of fear and social cognition that has been linked to trust and highly expresses oxytocin receptors in many mammals. However, no human data on the effects of this peptide on brain function were available. Here, we show that human amygdala function is strongly modulated by oxytocin. We used functional magnetic resonance imaging to image amygdala activation by fear-inducing visual stimuli in 15 healthy males after double-blind crossover intranasal application of placebo or oxytocin. Compared with placebo, oxytocin potently reduced activation of the amygdala and reduced coupling of the amygdala to brainstem regions implicated in autonomic and behavioral manifestations of fear. Our results indicate a neural mechanism for the effects of oxytocin in social cognition in the human brain and provide a methodology and rationale for exploring therapeutic strategies in disorders in which abnormal amygdala function has been implicated, such as social phobia or autism.

The ability to "read the mind" of other individuals, that is, to infer their mental state by interpreting subtle social cues, is indispensable in human social interaction. The neuropeptide oxytocin plays a central role in social approach behavior in nonhuman mammals. In a double-blind, placebo-controlled, within-subject design, 30 healthy male volunteers were tested for their ability to infer the affective mental state of others using the Reading the Mind in the Eyes Test (RMET) after intranasal administration of 24 IU oxytocin. Oxytocin improved performance on the RMET compared with placebo. This effect was pronounced for difficult compared with easy items. Our data suggest that oxytocin improves the ability to infer the mental state of others from social cues of the eye region. Oxytocin might play a role in the pathogenesis of autism spectrum disorder, which is characterized by severe social impairment.

The present investigation was intended principally as a concurrent validation study for a new self-report symptom inventory: the SCL-90. A sample of 209 'symptomatic volunteers' served as subjects and were administered both the SCL-90 and the MMPI prior to participation in clinical therapeutic drug trials. The MMPI was scored for the Wiggins content scales and the Tryon cluster scales in addition to the standard clinical scales. Comparisons of the nine primary symptom dimensions of the SCL-90 with the set of MMPI scales reflected very high convergent validity for the SCL-90. Peak correlations were observed with like constructs on eight of the nine scales, with secondary patterns of correlations showing high interpretative consistency.