Barber et al. noted that similar factors appeared to mediate the response both to hypnotism and to cognitive behavioural therapy, in particular systematic desensitization. Hence, research and clinical practice inspired by their interpretation has led to growing interest in the relationship between hypnotherapy and cognitive behavioural therapy.:105
He also believed that hypnosis was a "partial sleep", meaning that a generalised inhibition of cortical functioning could be encouraged to spread throughout regions of the brain. He observed that the various degrees of hypnosis did not significantly differ physiologically from the waking state and hypnosis depended on insignificant changes of environmental stimuli. Pavlov also suggested that lower-brain-stem mechanisms were involved in hypnotic conditioning.
Hypnosis has long been considered a valuable technique for recreating and then studying puzzling psychological phenomena. A classic example of this approach uses a technique known as posthypnotic amnesia (PHA) to model memory disorders such as functional amnesia, which involves a sudden memory loss typically due to some sort of psychological trauma (rather than to brain damage or disease). Hypnotists produce PHA by suggesting to a hypnotized person that after hypnosis he will forget particular things until he receives a “cancellation,” such as “Now you can remember everything.” PHA typically only happens when it is specifically suggested and it is much more likely to occur in those with high levels of hypnotic ability, or “high hypnotizable” people. Now a new study shows that this hypnotic state actually influences brain activity associated with memory.
In the 2000s, hypnotherapists began to combine aspects of solution-focused brief therapy (SFBT) with Ericksonian hypnotherapy to produce therapy that was goal focused (what the client wanted to achieve) rather than the more traditional problem focused approach (spending time discussing the issues that brought the client to seek help). A solution-focused hypnotherapy session may include techniques from NLP.