Transtheoretical Model: Stages of Health Behavior Change

Prochaska and DiClemente (1983) noticed that the change from unhealthy behavior (smoking) to healthy behavior (not smoking) is complex and involves a series of stages.

These stages do not happen in a linear order; the process is often cyclical. Some stages may be missed, or the addicts might go back to an earlier stage before progressing again.

The model considers how ready people are to quit the addiction and adapts intervention to the stage the client is at.

Prochaska’s model of behavior change proposes that overcoming an addiction is the process during which an individual goes through a series of stages. These stages do not happen in a linear order; the process is often cyclical. Some stages may be missed, or the addicts might go back to an earlier stage before progressing again.

The first stage is pre-contemplation. At this stage, people are not considering changing their behavior in the near future. They might be in denial or feel demotivated by their failure in previous attempts. The following stage is contemplation; at this stage, people become increasingly aware that they need to change.

They consider the advantages and the cost of changing. This stage can last for a long time. At this stage, intervention should help the client see that the pros outweigh the cons.

Preparation is the following stage. At this stage, the individual has decided to change but has not got a plan on how to do it yet. Any intervention should focus on helping the client to decide which support will be needed to achieve the change successfully, e.g., contact GP, specialized clinics, or helpline.

Then comes the action stage. People change their behavior, e.g., they get rid of all tobacco products and lighters …. Relapse can happen. Intervention should focus on supporting the individual with practical help, praise, and rewards .. to maintain the change.

Maintenance then occurs. The individual has maintained the change for at least six months and is growing in confidence that the change can be permanent. Intervention at this stage focuses on strategies learned to prevent relapse, e.g., emphasizing the benefits of stopping the addiction…

Finally, the last stage is termination. The change is permanent and stable. Abstinence is now automatic; there is no relapse. Some people do not achieve this stage and remain in the maintenance stage for many years. Relapse for them is still possible.

Critical Evaluation

It offers a different focus of intervention at every stage; this should lead to more individually tailored interventions which are more likely to be successful than a “one size fit all” approach.

However, the research carried out on the effectiveness of this model is inconclusive.

Velicer et al. (2007) reviewed five studies and found a 22-26 success rate, which compared well with other interventions. However, Aveyard et al. (2009) found that tailoring intervention to the stages of change did not increase its effectiveness in individuals who were trying to stop smoking.

Similarly, Baumann et al. (2015) carried out a study on randomly allocated alcohol addicts to an experimental group and to a control group. They found no beneficial effect of a staged intervention.

The model is flexible and dynamic. It reflects the changing emotions and attitudes that addicts have toward their condition.  Sometimes they appear to be in denial, and at other times they recognize that their addiction is a problem.

The model encourages a more realistic view of relapse, which is seen as an inevitable part of the process rather than a failure on the part of the client. This is a strength as it avoids the low self-confidence and demotivation likely to arise if the client sees relapse as a failure.

One weakness of the model is that the difference between stages is often “blurry,” e.g., the difference between contemplation and preparedness is vague.

So it is questionable whether they are in fact two distinct stages.

A further weakness is that the model neglects the influence of social factors, for example, living conditions, unemployment, and the perceived social norms within this environment.


Prochaska, J. O., & DiClemente, C. C. (1983). Stages and processes of self-change of smoking: toward an integrative model of change . Journal of consulting and clinical psychology, 51(3), 390.

Saul Mcleod, PhD

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Educator, Researcher

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education.

Elisabeth Brookes

Psychology Teacher

BSc (Hons), Psychology

Elisabeth Brookes has worked as a psychology teacher at Luton Sixth Form College.