The syndrome of multiple (dissociated) personality fell into disrepute around 1910. This has been attributed to loss of interest in hypnosis; psychiatrists believed the syndrome resulted from hypnosis and that they were duped. However, around 1910 an important event occurred in psychiatry: Bleuler introduced the term "schizophrenia' to replace "dementia praecox.' This factor also played a role in the decline of recognition of the multiple personality syndrome, and many of these cases were diagnosed as schizophrenia.
Animal hypnosis is a prolonged immobility response which may be defined according to several physiological parameters. In the rabbit, EEG, hyppocampal rhythmic activity, spinal reflexes and local cerebral glucose utilization are modified during this condition. The duration of the response is affected by persistent nociceptive stimuli. Corticosterone plasma levels are correlated with individual susceptibility and elevated when habituation to hypnosis occurs. Testosterone metabolism in the hypothalamus is found decreased after a single trial and increased following repeated trials.