I first thought about this while reading Aldous Huxley's, 'The Doors of Perception/Heaven and Hell', in which he speaks about his own experiments with masculine. He draws upon the ideas of Henri Bergson, in which the brain is seen as 'a filter' for 'mind at large'. It was this that made me become interested in psychedelia, as well as a fascination with psyche rock music.
One particular researcher in this area is Stanislav Grof, who has looked at the parallels between perinatal experiences and the way in which drug altered mental states mimic states of psychosis, resembling schizophrenia. Indeed, in mainstream psychiatry there is a general consensus that the use of hallucinogenics, including cannabis, can trigger psychotic states.
The work of Timothy Leary, an extremely controversial writer, who influenced the psychedelic counterculture movement, was particularly significant, especially in relation to the idea of 'psychedelic' as mind-expanding. He compared psychedelic experiences and the descriptions in 'The Tibetan Book of the Dead'. He was not thinking of these descriptions as signifying life after death as such, but looking at them in relation to mental states of awareness which are considered to a state of enlightenment.
Thinking about hallucinogenic substances in this way is different from their use in party culture, although it may be that many drawn to use them have a deeper interest in mind expansion. One area of research in the present time is different from the experiments in the 1960s and 70s, because it is less dramatic and involves microdosing on hallucinogenics for the treatment of depression. I understand that this is an area of clinical trials at this stage. In this thread, I am opening up discussion of what do psychedelic experiences show about the nature of 'reality', the brain and the nature of 'mind' and its healing?