Obituary of Dr. Harold A. Widdison, a researcher in the field of near-death studies for over 30 years. The article discusses Dr. Widdison's background, career, family, and contributions to the study of near-death experiences.

Abstract: Some NDE researchers have suggested that because some users of psychedelic drugs have experiences purportedly similar to near-death experiences (NDEs), neural receptors and neurotransmitters affected by a particular drug may underlie out-of-body experiences and NDEs. One of the most recent psychedelic candidates that allegedly causes NDE-like experiences is N,N-dimethyltryptamine (DMT), a natural substance that the body produces in small amounts. If DMT experiences are phenomenologically similar to NDEs, then it is possible that the human body in extremis may produce larger amounts of DMT that reach psychedelic experience-causing levels in the blood. In this paper, I explore the issue of whether DMT might play a causal role in the production of NDEs. The first section summarizes basic information of about NDEs, focusing on their phenomenological aspects. The second section classifies theories of NDEs to place the DMT theory in some context of the history of the debate over the cause of NDEs. The following section discusses DMT's chemical composition, physical effects, and psychological effects. The final section explores whether NDE and DMT experiences have a sufficient degree of phenomenological similarity to justify a causal role for DMT in the production of NDEs and concludes that such similarity is lacking.