Transtheoretical principles and processes for quitting smoking: a 24-month comparison of a representative sample of quitters, relapsers, and non-quitters.

This longitudinal study compared 14 principles and processes of change applied by successful quitters, relapsers and non-quitters over 24 months in a representative sample of 4144 smokers in intervention and control groups. The successful quitters showed a decrease in the use of experiential processes (cognitive, affective and effective) and an increase in behavioral processes (e.g., counter-conditioning and stimulus control). The non-quitters showed little change in their use of almost all of the processes. The relapsers' use of the processes tended to initially parallel the successful quitters, but over time, their use ended up between the quitters and the non-quitters. In general, the relapsers ended up working harder but not smarter than the successful quitters. The pattern of use of change processes in the treatment and control groups were remarkably similar, suggesting common pathways to change.