My answer on Quora:
I don’t use the word ‘cure’, but hypnotherapy and related techniques can certainly help insomnia.
My normal approach is to teach clients self-help techniques that I’ve successfully used for myself – self-hypnosis, EFT (Emotional Freedom Techniques) and a few other things. I also give them instruction in ‘sleep hygiene’ – changing various habits which can have a negative effect on sleep patterns.
Usually clients find that one or more of these techniques work for them, but occasionally it may be necessary to deal with underlying causes; stress is an obvious one, but there may also be something buried in the unconscious mind that needs to be found through analytical methods such as regression or parts work.