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 .
Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects
BACKGROUND After no research in humans for > 40 years , there is renewed interest in using lysergic acid diethylamide ( LSD ) in clinical psychiatric research and practice . There are no modern studies on the subjective and autonomic effects of LSD , and its endocrine effects are unknown . In animals , LSD disrupts prepulse inhibition ( PPI ) of the acoustic startle response , and patients with schizophrenia exhibit similar impairments in PPI . However , no data are available on the effects of LSD on PPI in humans . METHODS In a double-blind , r and omized , placebo-controlled , crossover study , LSD ( 200 μg ) and placebo were administered to 16 healthy subjects ( 8 women , 8 men ) . Outcome measures included psychometric scales ; investigator ratings ; PPI of the acoustic startle response ; and autonomic , endocrine , and adverse effects . RESULTS Administration of LSD to healthy subjects produced pronounced alterations in waking consciousness that lasted 12 hours . The predominant effects induced by LSD  included visual hallucinations , audiovisual synesthesia , and positively experienced derealization and depersonalization phenomena . Subjective well-being , happiness , closeness to others , openness , and trust were increased by LSD . Compared with placebo , LSD  decreased PPI  . LSD significantly increased blood pressure , heart rate , body temperature , pupil size , plasma cortisol , prolactin , oxytocin , and epinephrine . Adverse effects produced by LSD completely subsided within 72 hours . No severe acute adverse effects were observed . CONCLUSIONS In addition to marked hallucinogenic effects , LSD exerts methylenedioxymethamphetamine-like empathogenic mood effects that may be useful in psychotherapy . LSD altered sensorimotor gating in a human model of psychosis , supporting the use of LSD in translational psychiatric research . In a controlled clinical setting , LSD can be used safely , but it produces significant sympathomimetic stimulation
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 .