Contemporary hypnotism uses a variety of suggestion forms including direct verbal suggestions, "indirect" verbal suggestions such as requests or insinuations, metaphors and other rhetorical figures of speech, and non-verbal suggestion in the form of mental imagery, voice tonality, and physical manipulation. A distinction is commonly made between suggestions delivered "permissively" and those delivered in a more "authoritarian" manner. Harvard hypnotherapist Deirdre Barrett writes that most modern research suggestions are designed to bring about immediate responses, whereas hypnotherapeutic suggestions are usually post-hypnotic ones that are intended to trigger responses affecting behaviour for periods ranging from days to a lifetime in duration. The hypnotherapeutic ones are often repeated in multiple sessions before they achieve peak effectiveness.[39]
Psychiatric nurses in most medical facilities are allowed to administer hypnosis to patients in order to relieve symptoms such as anxiety, arousal, negative behaviours, uncontrollable behaviour, and to improve self-esteem and confidence. This is permitted only when they have been completely trained about their clinical side effects and while under supervision when administering it.[147]
But the reason why this ever works, for anyone, is still not clear. Some researchers argue that hypnosis may help us tap into “the autonomic nervous system to influence physical systems that aren’t usually under voluntary control,” Marchant writes in her book. She points to Karen Olness, a retired pediatrician and former member of the NIH Council for Complementary and Alternative Medicine, who has worked with children who could, through hypnosis, increase the temperature of their fingertips “way beyond what would be achieved merely from relaxation.”
This method of hypnotherapy is commonly beneficial to hypnotherapists in discovering the psychological root of a problem or symptom, such as social anxiety, depression, or past trauma. These types of trauma are often hidden in unconscious memory and forgotten on a conscious level. Using hypnotherapy for analysis has proven particularly effective at digging into the subconscious memory to attempt to retrieve suppressed memories or early developmental trauma that could result in a wide range of psychological conditions or problematic behavior.

In the everyday trance of a daydream or movie, an imaginary world seems somewhat real to you, in the sense that it fully engages your emotions. Imaginary events can cause real fear, sadness or happiness, and you may even jolt in your seat if you are surprised by something (a monster leaping from the shadows, for example). Some researchers categorize all such trances as forms of self-hypnosis. Milton Erickson, the premier hypnotism expert of the 20th century, contended that people hypnotize themselves on a daily basis. But most psychiatrists focus on the trance state brought on by intentional relaxation and focusing exercises. This deep hypnosis is often compared to the relaxed mental state between wakefulness and sleep.
This popular representation bears little resemblance to actual hypnotism, of course. In fact, modern understanding of hypnosis contradicts this conception on several key points. Subjects in a hypnotic trance are not slaves to their "masters" -- they have absolute free will. And they're not really in a semi-sleep state -- they're actually hyperattentive.
In the 1950s, Milton H. Erickson developed a radically different approach to hypnotism, which has subsequently become known as "Ericksonian hypnotherapy" or "Neo-Ericksonian hypnotherapy." Erickson made use of an informal conversational approach with many clients and complex language patterns, and therapeutic strategies. This divergence from tradition led some of his colleagues, including Andre Weitzenhoffer, to dispute whether Erickson was right to label his approach "hypnosis" at all.[10]