Green, M.F. Impact of cognitive and social cognitive impairment on functional outcomes in patients with schizophrenia. J. Clin. Psychiatry 2016, 77, 8–11.

Richards, W.A.; Rhead, J.C.; Dileo, F.B.; Yensen, R.; Kurland, A.A. The Peak Experience Variable in DPT-Assisted Psychotherapy with Cancer Patients. J. Psychedelic Drugs 1977, 9, 1–10. Even though the subjective paranormal experiences, clinical observations and anthropological reports are subject to all the usual criticisms and rebuttals that apply to non-experimental cases 124 there is a growing body of reports, rooted in thousands of years of traditional psychedelic use, that supports the notion that genuine psi phenomena do occur in psychedelic states. As evidence these data are not scientifically rigorous, but they have great value in mapping the phenomenological terrain of psi experiences with psychedelics. This body of reports is further supported by correlations from surveys linking psychedelic use with the increased reporting of psi experiences and belief in psi and the paranormal, although self-reports have more phenomenological merit than evidential value. Furthermore, even though it can be considered little more than exploratory at this stage, the experimental evidence is mostly positive and proves promising so far, illuminating both methodological pitfalls and possibilities. DMT (N,N-dimethyltryptamine) is an indole alkaloid found in various species of plants. Traditionally it is consumed by tribes in South America in the form of ayahuasca. A brew is used that consists of DMT-containing plants as well as plants containing MAOIs, specifically harmaline, which allows DMT to be consumed orally without being rendered inactive by monoamine oxidase enzymes in the digestive system. [40] In the Western world DMT is more commonly consumed via the vaporisation of freebase DMT. Whereas Ayahuasca typically lasts for several hours, inhalation has an onset measured in seconds and has effects measured in minutes, being significantly more intense. [41] Particularly in vaporised form, DMT has the ability to cause users to enter a hallucinatory realm fully detached from reality, being typically characterised by hyperbolic geometry, and described as defying visual or verbal description. [42] Users have also reported encountering and communicating with entitites within this hallucinatory state. [43] DMT is the archetypal substituted tryptamine, being the structural scaffold of psilocybin and - to a lesser extent - the lysergamides. Frantzi, M.; Bhat, A.; Latosinska, A. Clinical proteomic biomarkers: Relevant issues on study design & technical considerations in biomarker development. Clin. Transl. Med. 2014, 3, 7.In 2004, David E. Nichols wrote the following about the nomenclature used for psychedelic drugs: [32] Andersen, K.A.A.; Carhart-Harris, R.; Nutt, D.J.; Erritzoe, D. Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern-era clinical studies. Acta Psychiatr. Scand. 2021, 143, 101–118.

British Association for Psychopharmacology of Schizophrenia. Evidence-Based Guidelines for the Pharmacological Treatment of Schizophrenia: Recommendations from the British Association for Psychopharmacology. Available online: https://www.bap.org.uk (accessed on 7 November 2021).Brown, D.J. (2012). LSD & ESP: Scientists study psychic phenomena and psychedelic drugs. Santa Cruz Patch (online, 9 June, link defunct). Heekeren, K.; Neukirch, A.; Daumann, J.; Stoll, M.; Obradovic, M.; Kovar, K.-A.; Geyer, M.A.; Gouzoulis-Mayfrank, E. Prepulse inhibition of the startle reflex and its attentional modulation in the human S-ketamine and N,N-dimethyltryptamine (DMT) models of psychosis. J. Psychopharmacol. 2007, 21, 312–320.