Though the evidence for this is purely anecdotal, it has been reported that psychic abilities can be enhanced through the use of hypnosis. Obviously this requires that you accept the fact of psychic abilities before trying to establish if hypnosis does anything to enhance it. It is not possible to hypnotize someone against their will. This means that for hypnosis to work, there must be cooperation between the practitioner and the subject. Any inhibition or unwillingness to trust the practitioner will result in failure. In truth, the practitioner is merely an assistant who helps the subjects hypnotize themselves. The subject is always in charge and will not accept any suggestions that are not in sync with their own. Whatever stories you may have heard about people doing weird things under the influence of hypnosis are completely untrue.
Historically, hypnotism has been around since the old days when sorcery was accepted as a fact. More practical is the fact of Sigmund Freud using hypnosis in his efforts to understand the unconscious mind. Nowadays, hypnosis is used for many different ends like modifying behavior, therapy, healing bad memories, and so on. Despite this long history, it is surprising that there is no commonly accepted definition of what exactly happens during hypnosis and how the mind is affected. There are many differing theories that attempt to clarify the situation.
The unconscious mind is more responsible for our habits so it is believed that hypnosis helps with curing these habits because during a trance the conscious and unconscious parts of our mind communicate freely and the unconscious is more receptive to suggestions.
There have been many experiments trying to establish and explain the link between hypnosis and ESP but the results are not as clear as one might desire. What was truly surprising in these tests was the discovery of something that has been labeled as "Negative ESP". Most of the ESP tests require the test subjects to ascertain something without making use of any of the five common senses of human beings. Describing a picture they cannot see or the order of cards in a shuffled deck, and so on. When these tests are designed, it is already known that there is always the chance of a random instance when someone will give all the right answers, even without ESP. This is accounted for and the final results are those that go beyond the random factor.
Research conducted by Indians has formed the basis of the traits that are used in classifying people with positive and negative ESP, at least in experiments. Positive ESP subjects are typically known to be extroverts that are outgoing, adventurous, enthusiastic, and always at ease. Negative ESP subjects are known for being more withdraw, always a bit tense, readily frustrated, and quite suspicious without reason. It was finally concluded that negative ESP was basically an outcome of these individual traits rather than the reverse.
In the final result, hypnosis has been shown to increase the ESP of a given subject by relaxing the mind and permitting more subconscious control and refining the mental processes involved in perception.