On the MAPS website:

Hallucinogenic Drugs in Experimental Psychiatric Research (1997)
Are Entactogens A New Class of Psychoactive Agents? (1993)

Published papers:

Neuropsychopharmacology 1999 Jun;20(6):565-81 Neurometabolic effects of psilocybin, 3,4-methylenedioxyethylamphetamine (MDE) and d-methamphetamine in healthy volunteers. A double-blind, placebo-controlled PET study with [18F]FDG.
Gouzoulis-Mayfrank E, Schreckenberger M, Sabri O, Arning C, Thelen B, Spitzer M, Kovar KA, Hermle L, Bull U, Sass H - Department of Psychiatry and Psychotherapy, University of Technology, Aachen, Germany.

The neurometabolic effects of the hallucinogen psilocybin (PSI; 0.2 mg/kg), the entactogen 3,4-methylenedioxyethylamphetamine (MDE; 2 mg/kg) and the stimulant d-methamphetamine (METH; 0.2-0.4 mg/kg) and the drugs' interactions with a prefrontal activation task were investigated in a double-blind, placebo-controlled human [F-18]fluorodeoxyglucoseFDG-positron emission tomographic PET study (each group: n = 8). Subjects underwent two scans (control: word repetition; activation word association) within 2-4 weeks. Psilocybin increased rMRGlu in distinct right hemispheric frontotemporal cortical regions, particularly in the anterior cingulate and decreased rMRGlu in the thalamus. Both MDE and METH induced cortical hypometabolism and cerebellar hypermetabolism. In the MDE group, cortical hypometabolism was more pronounced in frontal regions, with the exception of the right anterior cingulate, which tended to be hyperactive. Cognitive activation-related increases in left frontocortical regions were attenuated under all three psychoactive substances, but less so under MDE. Taking into account performance data and subjective reports on task difficulty, these effects may result from different mechanisms across the three groups. Our PSI data are in line with studies on acute schizophrenic patients suggesting frontal overactivity at rest, but diminished capacity to activate prefrontal regions upon cognitive demand. The MDE data support the hypothesis that entactogens constitute a distinct psychoactive substance class, which takes an intermediate position between stimulants and hallucinogens.

Psychopharmacology 1999 (Berl) Feb;142(1):41-50
Psychopathological, neuroendocrine and autonomic effects of 3,4-methylenedioxyethylamphetamine (MDE), psilocybin and d-methamphetamine in healthy volunteers. Results of an experimental double-blind placebo-controlled study.
Gouzoulis-Mayfrank E, Thelen B, Habermeyer E, Kunert HJ, Kovar KA, Lindenblatt H, Hermle L, Spitzer M, Sass H

The aim of this study was to contribute to the characterization of the entactogen (ecstasy) substance group. The psychopathological, neuroendocrine and autonomic effects of common recreational doses of the entactogen 3,4-methylenedioxyethylamphetamine (MDE), the hallucinogen psilocybin, the stimulant d-methamphetamine and placebo were investigated in a double-blind study with healthy volunteers (n = 32). Psychological effects of the drugs were assessed by means of standardized rating scales, self assessment inventories and free descriptions. The most characteristic effects of MDE were pleasant emotional experiences of relaxation, peacefulness, content and closeness to others. However, significant stimulant and hallucinogen-like effects were also present, although the latter were weaker than the effects of psilocybin. MDE elicited the strongest endocrine and autonomic effects among the three drugs, including robust rises of serum cortisol and prolactin, elevations of blood pressure and heart rate, and a moderate, but significant rise of body temperature. The apparent contrast between psychological and autonomic effects (subjective relaxation versus physical activation) was a unique feature of the MDE state. Our findings are in line with both users' reports and results from previous experimental studies, and support the view that entactogens constitute a distinct psychoactive substance class taking an intermediate position between hallucinogens and stimulants.

Pharmacopsychiatry 1998 Jul;31 Suppl 2:85-91
Blood flow and cerebral laterality in the mescaline model of psychosis.
Hermle L, Gouzoulis-Mayfrank E, Spitzer M

Department of Psychiatry, Christophsbad, Goppingen, Germany. The psychological, neuropsychological, and neurometabolic effects of the hallucinogenic agent mescaline were investigated in 12 normal male volunteers. Between 3 1/2 and 4 hours after drug intake, mescaline produced an acute psychotomimetic state, as measured by the BPRS and PDS-P. The APZ questionnaire revealed the specific effects of mescaline in the visual system. Neuropsychological effects were studied with a face/non-face decision task with known right hemisphere advantage, in which mescaline induced a decrease in functioning of the right hemisphere. In functional brain imaging using SPECT, mescaline produced a "hyperfrontal" pattern with an emphasis on the right hemisphere, which was correlated with mescaline-induced psychotomimetic psychopathology. Our findings question the validity of the concept of hypofrontality as an explanation for acute psychotic symptomatology. PMID: 9754839, UI: 98425834

Other papers:

Schreckenberger M, et al. "Ecstasy"-induced changes of cerebral glucose metabolism and their correlation to acute psychopathology. An 18-FDG PET study. Eur J Nucl Med. 1999 Dec;26(12):1572-9. [MEDLINE record in process] PMID: 10638409; UI: 20103764.

Gouzoulis-Mayfrank E, et al. Neurometabolic effects of psilocybin, 3,4-methylenedioxyethylamphetamine (MDE) and d-methamphetamine in healthy volunteers. A double-blind, placebo-controlled PET study with [18F]FDG. Neuropsychopharmacology. 1999 Jun;20(6):565-81. PMID: 10327426; UI: 99259410.

Gouzoulis-Mayfrank E, et al. Psychopathological, neuroendocrine and autonomic effects of 3,4-methylenedioxyethylamphetamine (MDE), psilocybin and d-methamphetamine in healthy volunteers. Results of an experimental double-blind placebo-controlled study. Psychopharmacology (Berl). 1999 Feb;142(1):41-50. PMID: 10102781; UI: 99200926.

Brunnenberg M, et al. Quantitation of N-ethyl-3,4-methylenedioxyamphetamine and its major metabolites in human plasma by high-performance liquid chromatography and fluorescence detection. J Chromatogr B Biomed Sci App. 1998 Nov 20;719(1-2):79-85. PMID: 9869367; UI: 99084712.

Schreckenberger M, et al. [Investigations on the effect of "ecstasy" on cerebral glucose metabolism: an 18-FDG PET study]. Nuklearmedizin. 1998;37(8):262-7. German. PMID: 9868707; UI: 99085598.

Gouzoulis-Mayfrank E, et al. Effects of the hallucinogen psilocybin on habituation and prepulse inhibition of the startle reflex in humans. Behav Pharmacol. 1998 Nov;9(7):561-6. PMID: 9862081; UI: 99079074.

Schreckenberger M, et al. Cerebral interregional correlations of associative language processing: a positron emission tomography activation study using fluorine-18 fluorodeoxyglucose. Eur J Nucl Med. 1998 Nov;25(11):1511-9. PMID: 9799347; UI: 99016067.

Gouzoulis-Mayfrank E, et al. Methodological issues of human experimental research with hallucinogens. Pharmacopsychiatry. 1998 Jul;31 Suppl 2:114-8. Review. PMID: 9754843; UI: 98425838.

Hermle L, et al. Blood flow and cerebral laterality in the mescaline model of psychosis. Pharmacopsychiatry. 1998 Jul;31 Suppl 2:85-91. PMID: 9754839; UI: 98425834.

Gouzoulis-Mayfrank E, et al. History, rationale and potential of human experimental hallucinogenic drug research in psychiatry. Pharmacopsychiatry. 1998 Jul;31 Suppl 2:63-8. PMID: 9754835; UI: 98425830.

Lindenblatt H, et al. Quantitation of psilocin in human plasma by high-performance liquid chromatography and electrochemical detection: comparison of liquid-liquid extraction with automated on-line solid-phase extraction. J Chromatogr B Biomed Sci App. 1998 May 29;709(2):255-63. PMID: 9657222; UI: 98319304.

Hermle L, et al. [Hallucinogen induced psychic disorders. Subjective experiences, psychopathology and differential diagnosis]. Fortschr Neurol Psychiatr. 1996 Dec;64(12):482-91. German. PMID: 9053389; UI: 97173494.

Spitzer M, et al. Increased activation of indirect semantic associations under psilocybin. Biol Psychiatry. 1996 Jun 15;39(12):1055-7. No abstract available. PMID: 8780843; UI: 96374616.

Gouzoulis-Mayfrank E, et al. [Entactogenic drugs "ecstasy" (MDMA), "eve" (MDE) and other ring-substituted methamphetamine derivatives. A new class of substances among illegal designer drugs]? Nervenarzt. 1996 May;67(5):369-80. Review. German. PMID: 9005345; UI: 97128124.

Ensslin HK, et al. (1996) Metabolism of racemic 3,4-methylenedioxyethylamphetamine in humans. Isolation, identification, quantification, and synthesis of urinary metabolites. Drug Metab Dispos. 1996 Aug;24(8):813-20.

Gouzoulis E, et al. (1993) Neuroendocrine and cardiovascular effects of MDE in healthy volunteers. Neuropsychopharmacology. 1993 May;8(3):187-93.

Hermle L, et al. (1993) Psychological effects of MDE in normal subjects. Are entactogens a new class of psychoactive agents? Neuropsychopharmacology. 1993 Feb;8(2):171-6.

Gouzoulis E, et al. (1992) Sleep EEG effects of 3,4-methylenedioxyethamphetamine (MDE; "eve") in healthy volunteers. Biol Psychiatry. 1992 Dec 15;32(12):1108-17.