On the basis of the psychosomatic model, an interpretation of hypnositherapy is proposed in the psychobiological context as an applicative example of oneness. With this technique a particular state of awareness, which hypnosis is, correlated biologically with considerable subcortical neurophysiological modifications in the individual, is added, as a facilitating context, into the activation of patients psychotherapy. Thereafter the neurophysiological characterisation of the hypnotic state such as activation of the right hemisphere, similarities between transhypnosis and synchronous sleep and the activation of subcortical mechanisms compared to the cortical are considered. In the hypnotic situation, two very special conditions which are extremely important in the biological context, operate: on the one hand the special physician/patient relationship, on the other the important psychosomatic implication deriving from the possibility of direct action on mesolimbic and hypothalamus following the reduced cortical activity. After examining the context of the physician/patient relationship in the clinical implication of the placebo, or non-pharmacological effect of the drug implied, the psychosomatic activation mechanisms that can be the reason for modifications in the symptom, including its improvement or actual cure are considered. In this context, the psychosomatic evaluational parameter inherent in cognitive evaluation to which the cortical filter is correlated, the emotional activation to which activation of the limbic system is correlated and, finally, the set of psychophysiological variations correlated to this limbic activation underlying behavioural and somatic modifications are reviewed.