The Transtheoretical Model is an integrative model of behaviour change. The model describes how people modify a problem behaviour or acquire a positive behaviour. The central organising construct of the model is the Stages of Change. The five stages are Precontemplation, Contemplation, Preparation, Action and Maintenance. Most often, these phases do not follow a simple linear progression; instead, they are seen as a set of dynamically interacting components through which the individual will likely cycle a number of times before achieving sustained behaviour change.

Transition among stages results from experiential and behavioural processes that the individual may experience called the Processes of Change. Each of these stages are characterised by changes in decisional balance; that is, the balance between benefits and costs associated with engaging in a particular behaviour.

The Transtheoretical Model focuses on the decision making of an individual. The model involves emotions, cognitions, and behaviour.

Processes of Change: Experiential - Stopping Smoking

1. Consciousness Raising [Increasing awareness]
   
   I recall information people had given me on how to stop smoking
2. Dramatic Relief [Emotional arousal]
   
   I react emotionally to warnings about smoking cigarettes
3. Environmental Reevaluation [Social reappraisal]
   
   I consider the view that smoking can be harmful to the environment
4. Social Liberation [Environmental opportunities]
   
   I find society changing in ways that make it easier for the nonsmoker
5. Self Reevaluation [Self reappraisal]
   
   My dependency on cigarettes makes me feel disappointed in myself

II. Processes of Change: Behavioural - Stopping Smoking

1. Stimulus Control [Re-engineering]
   
   I remove things from my home that remind me of smoking
2. Helping Relationship [Supporting]
   
   I have someone who listens when I need to talk about my smoking
3. Counter Conditioning [Substituting]
   
   I find that doing other things with my hands is a good substitute for smoking
4. Reinforcement Management [Rewarding]
   
   I reward myself when I don’t smoke
5. Self Liberation [Committing]
   
   I make commitments not to smoke

The Transtheoretical Model makes no assumption about how ready individuals are to change. It recognises that different individuals will be in different stages and that appropriate interventions must be developed for everyone.

A wide range of health behaviours have been investigated using this paradigm, including smoking, drinking, eating disorders, and illicit drug use.