Long-term use was associated with thinning of the posterior cingulate cortex , thickening of the anterior cingulate cortex , and decreased neocortical 5-HT2A receptor binding .
Despite the high method ological heterogeneity and the small sample sizes , the results suggest that hallucinogens increase introspection and positive mood by modulating brain activity in the fronto-temporo-parieto-occipital cortex
Serotonergic hallucinogens produce alterations of perceptions , mood , and cognition , and have anxiolytic , antidepressant , and antiaddictive properties .
These drugs act as agonists of frontocortical 5-HT2A receptors , but the neural basis of their effects are not well understood .
Thus , we conducted a systematic review of neuroimaging studies analyzing the effects of serotonergic hallucinogens in man .
Antidepressant Effects of a Single Dose of Ayahuasca in Patients With Recurrent Depression: A SPECT Study
Abstract Ayahuasca is an Amazonian botanical hallucinogenic brew which contains dimethyltryptamine , a 5-HT2A receptor agonist , and harmine , a monoamine-oxidase A inhibitor . Our group recently reported that ayahuasca administration was associated with fast-acting antidepressive effects in 6 depressive patients . The objective of the present work was to assess the antidepressive potentials of ayahuasca in a bigger sample and to investigate its effects on regional cerebral blood flow . In an open-label trial conducted in an inpatient psychiatric unit , 17 patients with recurrent depression received an oral dose of ayahuasca ( 2.2 mL/kg ) and were evaluated with the Hamilton Rating Scale for Depression , the Montgomery-Åsberg Depression Rating Scale , the Brief Psychiatric Rating Scale , the Young Mania Rating Scale , and the Clinician Administered Dissociative States Scale during acute ayahuasca effects and 1 , 7 , 14 , and 21 days after drug intake . Blood perfusion was assessed eight hours after drug administration by means of single photon emission tomography . Ayahuasca administration was associated with increased psychoactivity ( Clinician Administered Dissociative States Scale ) and significant score decreases in depression-related scales ( Hamilton Rating Scale for Depression , Montgomery-Åsberg Depression Rating Scale , Brief Psychiatric Rating Scale ) from 80 minutes to day 21 . Increased blood perfusion in the left nucleus accumbens , right insula and left subgenual area , brain regions implicated in the regulation of mood and emotions , were observed after ayahuasca intake . Ayahuasca was well tolerated . Vomiting was the only adverse effect recorded , being reported by 47 % of the volunteers . Our results suggest that ayahuasca may have fast-acting and sustained antidepressive properties . These results should be replicated in r and omized , double-blind , placebo-controlled trials
Long-term use was associated with thinning of the posterior cingulate cortex , thickening of the anterior cingulate cortex , and decreased neocortical 5-HT2A receptor binding .
Despite the high method ological heterogeneity and the small sample sizes , the results suggest that hallucinogens increase introspection and positive mood by modulating brain activity in the fronto-temporo-parieto-occipital cortex
Serotonergic hallucinogens produce alterations of perceptions , mood , and cognition , and have anxiolytic , antidepressant , and antiaddictive properties .
These drugs act as agonists of frontocortical 5-HT2A receptors , but the neural basis of their effects are not well understood .
Thus , we conducted a systematic review of neuroimaging studies analyzing the effects of serotonergic hallucinogens in man .