Translational studies in humans
The study of altered states of consciousness induced by hallucinogenic substances in healthy volunteers has a long history in psychiatric research. This has been crucial to our work in Germany. By manipulating a neurotransmitter system in the brain, it is possible to produce symptoms that are similar to those observed in patients with psychoses. This allows us to examine the resulting changes in the brain's biology, as well as any behavioral and cognitive function changes.
We used exogenous cannabinoids exclusively to induce these altered states of consciousness. These cannabinoids mainly affect the body's endocannabinoid system, which allowed us to investigate the significant effects of this system on the aforementioned functions. We aimed to perform experiments in healthy individuals that were comparable to our animal experimental approaches. This ensured that the changes observed were as comparable as possible between the different species. This translational approach has contributed to a better understanding of the underlying neurobiological processes of endocannabinoidergic functions in psychiatric disorders.
Funding:
This research was supported by the European Commission (GxE Experimental EU FP7 HEALTH-F2-2010-241909).
Publications:
T. Woelfl, C. Rohleder, J. K. Mueller, B. Lange, A. Reuter, A. M. Schmidt, D. Koethe, M. Hellmich, F. M. Leweke: Effects of cannabidiol and delta-9-tetrahydrocannabinol on emotion, cognition and attention: A double-blind, placebo-controlled, randomized experimental trial in healthy volunteers. Front Psychiatry (2020) 11:576877
O. Grimm, M. Löffler, S. Camping, C. Rohleder, F. M. Leweke, H. Flor: Probing the endocannabinoid system in healthy volunteers: cannabidiol alters fronto-striatal resting-state connectivity. Eur Neuropsychopharmacol (2018) 28:841-849
D. Koethe, C. Hoyer, F. M. Leweke: The endocannabinoid system as a target for modelling psychosis. Psychopharmacology (2009) 206: 551-561.
D. Koethe, C. W. Gerth, M. A. Neatby, A. Haensel, C. Mauss, M. Thies, U. Schneider, H. M. Emrich, J. Klosterkötter, F. M. Leweke: Disturbances of visual information processing in early states of psychosis and experimental delta-9-Tetrahydrocannabinol altered states of consciousness. Schizophr Res (2006) 88(1-3):142-150.
D. Koethe, C. W. Gerth, M. A. Neatby, A. Haensel, C. Mauss, M. Thies, U. Schneider, H. M. Emrich, J. Klosterkötter, F. M. Leweke: Disturbances of visual information processing in early states of psychosis and experimental delta-9-Tetrahydrocannabinol altered states of consciousness. Schizophr Res (2006) 88(1-3):142-150.
F. M. Leweke, U. Schneider, M. Radwan, E. Schmidt, H. M. Emrich: Different effects of nabilone and cannabidiol on binocular depth inversion in man. Pharmacol Biochem Behav (2000) 66(1):175-181.
F. M. Leweke, U. Schneider, M. Thies, T. F. Münte, H. M. Emrich: Effects of synthetic ∆9-tetrahydrocannabinol on binocular depth inversion of natural and artificial objects in man. Psychopharmacology (1999) 142:230-235.