The Collaborative International Dictionary of English v.0.48:

Autosuggestion \Au`to*sug*ges"tion\, n. [Auto- + suggestion.]
   (Med.)
   1. Self-suggestion as distinguished from suggestion coming
      from another, especially in hypnotism. Autosuggestion is
      characteristic of certain mental conditions in which
      expectant belief tends to produce disturbance of function
      of one or more organs.
      [Webster 1913 Suppl.]

   2. hypnosis induced by oneself.

   Syn: self-hypnosis, self-suggestion.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

autosuggestion
    n 1: a system for self-improvement developed by Emile Coue which
         was popular in the 1920s and 1930s [syn: autosuggestion,
         auto-suggestion, self-suggestion]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "autosuggestion":
   animal magnetism, hypnology, hypnosis, hypnotherapy,
   hypnotic suggestion, hypnotism, mesmerism, mesmerization, od, odyl,
   odylic force, posthypnotic suggestion, power of suggestion,
   self-hypnosis, self-suggestion, suggestibility, suggestion therapy,
   suggestionism