Effects of ayahuasca on fear and anxiety: cross-talk between 5HT1A and 5HT2A receptors

Ayahuasca is a hallucinogenic substance currently being investigated for the treatment of mood, anxiety, and trauma-related disorders. Evidence from animal and human studies suggest that the effects of ayahuasca involve modulation of neural substrates relevant for emotional processing, especially in regions rich in serotonergic receptors. Moreover, preclinical studies also show that ayahuasca has specific effects on fear-related memories. The serotonergic system has been classically associated to anxiety and fear responses, with selective serotonin reuptake inhibitors being first-class medication to treat mood, anxiety, and stress-related disorders. Here we review currently available data regarding ayahuasca (and its main components) behavioral and functional effects on anxiety and fear-related responses through its modulation of serotoninergic signaling.