From Prochaska et al., 1994, 2002, 2014) -- the Transtheoretical Model proposes that behavior change occurs in five sequential stages: (1) precontemplation (not planning to change within the next 6 months), (2) contemplation (ambivalent or thinking about change), (3) preparation (taking steps towards changing), (4) action (attempting the change), and (5) maintenance (having been able to sustain behavior change for more than 6 months and working to prevent relapse). Furthermore, 10 “processes of change” are considered important in facilitating movement between different stages, and 2 additional variables influence that process: decisional balance (evaluating the pros and cons of changing) and self-efficacy. (see L. Laranjo, in Participatory Health Through Social Media, 2016).

Prochaska, J. O., Velicer, W. F., Rossi, J. S., Goldstein, M. G., Marcus, B. H., Rakowski, W., Fiore, C., Harlow, L. L., Redding, C. A., & Rosenbloom, D. (1994). Stages of change and decisional balance for 12 problem behaviors. Health psychology: official journal of the Division of Health Psychology, American Psychological Association, 13(1), 39–46. https://doi.org/10.1037//0278-6133.13.1.39

Prochaska, J. & Levesque, D. (2002). Enhancing motivation of offenders at each stage of change and phase of therapy. In M. McMurran (Ed.). Motivating Offenders to Change: A guide to Enhancing Engagement in Therapy (pgs. 57-74). Wiley Series in Forensic Clinical Psychology. 

Prochaska, J. O., Norcross, J. C., & DiClemente, C. C. (2013). Applying the stages of change. Psychotherapy in Australia, 19(2), 10-15.

Laranjo, L. (2016). Social media and health behavior change. In Syed-Abdul, E. Gabarron & A. Lau (Eds). Participatory Health Through Social Media (pgs. 83-111). https://doi.org/10.1016/C2015-0-05709-4