This digest examines the ways in which self-talk, or inner speech, can help change people's health states. The digest first examines research theories that underpin the concept, then discusses the development of a positive mental attitude, and finally offers some conclusions as to how individuals can best face challenges through taking an active role in deciding what to think. This involves enhancing the positive messages people send themselves but also involves being realistic, identifying the causes for whatever is negative and understanding it as a signal to act. (NKA)