Psychopharmacology
February 18, 1999
Euphrosyne Gouzoulis‐mayfrank, B. Thelen, Elmar Habermeyer et al.
145 citations
A double-blind study with 32 healthy volunteers compared the effects of the entactogen MDE (a drug similar to ecstasy), the hallucinogen psilocybin, the stimulant d-methamphetamine, and a placebo. MDE produced pleasant emotional experiences such as relaxation, peacefulness, contentment, and closeness to others, along with stimulant and mild hallucinogen-like effects. It caused the strongest endocrine and autonomic responses among the three drugs, including rises in cortisol, prolactin, blood pressure, heart rate, and a moderate increase in body temperature. The contrast between subjective relaxation and physical activation was unique to MDE. Results support entactogens as a distinct class between hallucinogens and stimulants.
Behavioural Pharmacology
November 1, 1998
Euphrosyne Gouzoulis‐mayfrank, Karsten Heekeren, B. Thelen et al.
79 citations
In a small double-blind, placebo-controlled study with 12 healthy subjects, the hallucinogen psilocybin increased prepulse inhibition (PPI) of the startle reflex, contrary to findings from animal models where hallucinogens disrupt PPI. Psilocybin had no clear effect on habituation of the startle reflex. These preliminary results suggest that the effects of hallucinogens on sensorimotor gating may differ between humans and animals, possibly due to differences in dose regimens or experimental parameters. Further research is needed to understand the relationship between hallucinogen-induced states and naturally occurring psychoses.
Neuropsychobiology
January 1, 2002
Euphrosyne Gouzoulis‐mayfrank, B. Thelen, Stefanie Maier et al.
69 citations
Psilocybin, a serotonergic hallucinogen, and the ecstasy-like drug MDE both slowed reaction times in a spatial attention task, while methamphetamine did not. Psilocybin caused especially slow responses to invalid cues at short intervals and a failure to inhibit responses to valid cues at long intervals for right visual field targets. These patterns resemble bilateral attention disengagement and a lateralized impairment of inhibition of return seen in acute psychotic states. The study used a double-blind design with 8 healthy volunteers per group. Limitations include small sample size, and the authors call for larger studies with other hallucinogens to explore links between visuospatial attention dysfunction and psychosis.
Journal of Psychopharmacology
May 1, 2007
Karsten Heekeren, Anna Neukirch, Jörg Daumann et al.
49 citations
Schizophrenia patients show reduced prepulse inhibition (PPI) of the startle reflex, but hallucinogen models of psychosis in healthy volunteers do not replicate this effect. In a double-blind crossover study with 15 healthy volunteers, the serotonergic hallucinogen DMT had no significant effect on PPI, while the NMDA antagonist S-ketamine increased PPI and decreased startle magnitude. Neither drug affected the attentional modulation of PPI. These results highlight differences between human hallucinogen models and both animal models and schizophrenia itself.
Fortschritte der Neurologie · Psychiatrie
May 29, 2008
Leopold Hermle, K.‐a. Kovar, Walter Hewer et al.
24 citations
Acute psychotic syndromes in adolescents are rarely due to intoxications with hallucinogenic drugs, but the clinical relevance of flashback phenomena as a post-hallucinogenic psychiatric disorder remains disputed. Because biogenic hallucinogens and LSD are increasingly popular among adolescents and young adults, knowledge of intoxications, resulting psychiatric disorders, medical complications, and therapeutic approaches is clinically important. Intoxications with drugs of herbal origin, such as tropane alkaloids, play an important role in emergency situations.