Psychonauts and schizophrenics see the same creatures

The Journal of Mental Science published an article in 1958
entitled Experiments with Dimethyltryptamine (DMT) and
Psychotics. The material included the work of researcher
Stephen Zahr, a Hungarian-born chemist and psychiatrist who
has published several articles on whether certain tryptamines
such as DMT may cause psychosis. Zara, in addition to being
one of the first clinical researchers to study the pharmacological
effects of DMT, also investigated the possibility that such
substances could be useful for therapeutic purposes. In a 1958
article by Zara examining the effects of DMT given to patients
with schizophrenia, one of his patients reported that he learned
of the existence of "strange creatures, gnomes, or whatever" 
shortly after he was injected with DMT. The following year, 
several patients were additionally injected with DMT, and only
one of them was able to recall any of their experiences after that.
“I lived in a world of orange people,” this patient said of her
experience with DMT. These studies continue to be notable for
being early pharmacological studies that noted an identity between
the hallucinatory experiences of patients with schizophrenia and
the visual psychedelic experiences that result from DMT use.
A second case study of the parallel between visions via DMT and
hallucinations in schizophrenic patients comes from a study by
psychologist Wilson Van Dusen, Ph.D., who conducted a study
in hundreds of schizophrenic patients. In Van Dusen's study, several
people suffering from hallucinations reported experiences of seeing
humanoid beings appearing in front of them. In an effort to better
understand the nature of these schizophrenic hallucinations, Van
Dusen took a new approach: by interacting with his patients, he tried
to interact with their hallucinations as if they were real.
By working with people who could distinguish between their own
conscious thoughts and those that seemed to emanate from the
hallucinations they perceived, Van Dusen hoped to establish a
relationship with both the patient and the entities they described,
with the patient acting as a mediator. Van Dusen interviewed his
patients, whose hallucinations he treated, as if they were real people
in a room with them. When speaking directly to these perceived 
entities, Van Dusen asked his patients to dictate their answers to him.
The results surprised Van Dusen and led to cases where he was able to
maintain a full conversation with these hallucinatory creatures for a
long time, and his patients acted as translators of this dialogue.
At times, Van Dusen was aware that entities were transmitting
information to him, which he determined was in many cases beyond
the understanding of his patients. Some of his patients also reported
that they felt that their encounters with beings were more contact with
beings from other places, rather than just hallucinations. Van Dusen
believed that there might be a connection between these entities and
other types of phenomena such as possession and other cases of the
paranormal and demons, wondering if the entities he interacted with
could really be something supernatural, or are they really bits and
pieces consciousness. Thus, the connection between the appearance
of entities, schizophrenia and hallucinogens has been experimentally
proven. In other words, we are dealing with something that is beyond
our perception until the brain enters a certain state.