Application of transtheoretical model (TTM) to addictive behaviors: need for fine tuning.

Over the last two decades, the transtheoretical model (TTM) has become well established in research and practice pertaining to health behaviors including addictive behaviors (Prochaska, DiClemente, & Norcross, 1992). A recent search found over 1,900 citations on the model making it among the most popular models in present day psychology (Scopus, 2006). The hallmark of TTM that distinguishes it from other models is that it focuses on explaining behavior change and specifies a time dimension, albeit arbitrary, for behavior change. The basic foundation of the model is that people move through successive stages during the process of a behavior change.

The irony inherent in the present status of the TTM has been the complete polarization of the scientific community into two camps--one of staunch proponents and the other of unshakable antagonists. On one hand, the model has a substantial following amongst investigators and clinicians buttressed by prolific research literature while on the other hand there is serious discontentment amongst many scholars regarding the scientific precision and application of the model.

The construct which forms the focus of most criticism leveled against the model is the "stages of change." This construct implies that change occurs over time (Prochaska, 2000). The construct is dynamic and enables a person to move from one stage to another while making a behavior change. Behavioral change has been proposed to start with the precontemplation stage when one is not considering change in the foreseeable future and evolve through the stages of contemplation, preparation, and action into the final stage of maintenance.

Researchers have questioned the validity of staging individuals on arbitrarily defined cut off points (Sutton, 2001). Whitelaw and colleagues (2000) note that the classifying people in "stages" have several problems. First, people can move through the stages of the model in minutes. Second, the validity of self-reported behavior with regard to stage is questionable. Third, significant number of people cannot be assigned to recognized stages. De Nooijher and colleagues (2005) also question the stability of the stages. Critiques have also argued that the model does little more than stating the obvious--the obvious being that individuals who are thinking of doing something will more likely end up doing that (West, 2005). Also, it has been mentioned that the predictions made by the model could be best inconclusive or even faulty when compared with contemporary theories. West (2005) has gone on record to label the model "a security blanket for researchers and clinicians" and maintains that the model only gives off the impression of being a rigorous scientific tool bent on giving "scientific labels" when a layman approach would suffice. A case has been made by West (2005), to bury the model and develop a new model that addresses all the limitations highlighted.

Sutton (2005) discusses the factors which make the application of the TTM to alcoholism and substance abuse quite different from its application to smoking. Apart from the greater number of studies that have applied TTM to smoking in contrast to the ones exploring alcoholism and substance abuse, there are significant qualitative differences between the applications. More powerful designs have been applied in smoking studies. Moreover, while studies on smoking have utilized staging algorithms studies exploring alcohol and drug change have employed multidimensional questionnaires which may have at least partially affected the results. The criticisms leveled against the theory in general seem to hold equally well for its application to alcoholism and substance abuse.

The criticism could be done justice by either bidding a premature farewell (West, 2005) and as West puts it "revert to simple questions about desire to change that were in place before the TTM model was developed". As easy as it may sound, a reversion to the formerly prevalent dichotomous yes/no questions may not be adequate for at least 2 reasons. First, simplistic yes/no questions can not substitute the stage classification that TTM provides. This means that physicians and health care providers will either end up counseling all individuals to an equal extent (certainly not a cost effective proposition) or tailor their advice based entirely on the yes/no responses obtained. While simplistic than TTM, this approach may still be plagued with arbitrary classification, non inclusion of subconscious motivations that govern individual behavior and the other criticisms leveled against the TTM.

As a second reaction to the criticism, we could seek to scrutinize the shortcomings and make a sincere endeavor to fine tune the shortcomings. Intuition dictates that refinements may be justified than abandonment for reasons more than one. The model enjoys immense popularity and instant discontinuation through discrediting may simply not be possible. Secondly, the vast literature that backs this model stands to support the notion that the model works at least partially. By extension then, what works partially can be modified and improved to work more efficiently.

While most of the studies based on TTM and dealing with addictive behaviors revolve around smoking, research evidence although not as extensive still exists for alcohol and substance abuse. Three basic ways in which the application of the TTM to alcoholism and substance abuse can be better tested are as follows. Future studies should employ longitudinal designs which are definitely a better way of testing if discrete stages as hypothesized by the model actually exist. Secondly, staging algorithms should be used instead of the more commonly employed multidimensional questionnaires. Further, an attempt should also be made to explore if there is any difference between the cohesion of the constructs of the stage definitions (intention, time since quit) when the stages are defined through staging algorithms as opposed to staging questionnaires. Another limitation of the model is that usually theories aim for parsimony or use of few constructs to predict the phenomenon. The TTM is not parsimonious (West, 2006). There is a need to make TTM parsimonious, so that it can serve better practical utility. Finally, caution should be exercised in offering the recommendations and generalizations from a study. Unless more rigorous studies yield unanimous results in favor of the model, care should be taken by clinicians while dealing with individuals engaged in alcoholism and/or substance abuse and professionals should refrain from "withholding" counsel or treatment options based simply on the label or the particular stage that individual happens to be in, at that moment.

REFERENCES

Prochaska, J. O., DiClemente, C. C., & Norcross, J. C. (1992). In search of how people change. Applications to addictive behaviors. The American psychologist, 47(9), 1102-1114.

Prochaska, J. O. (2000). Change at differing stages. In C. R. Snyder, & R. E. Ingrain (Eds.). Handbook of psychological change. Psychotherapy processes and practices for the 21st century. (pp. 109-127). New York: John Wiley and Sons, Inc.

Sutton, S. (2001). Back to the drawing board? A review of applications of the transtheoretical model to substance use. Addiction, 96(1), 175-186.

De Nooijer, J., Van Assema, P., De Vet, E., & Brug, J. (2005) How stable are stages of change for nutrition behaviors in the Netherlands? Health Promotion International, 20, 27-32.

Scopus. (2006). Scopus advanced Search. Retrieved September 28, 2006, from http://www.scopus.com

Sutton, S. (2005). Another nail in the coffin of the transtheoretical model? A comment on West (2005). Addiction, 100, 1043-1046

West, R. (2005). Time for a change: putting the Transtheoretical (Stages of Change) Model to rest. Addiction, 100, 1036-1039.

West, R. (2006). The transtheoretical model of behavior change and the scientific method. Addiction, 101, 774-778.

Whitelaw, S., Baldwin, S., Bunton, R., & Flynn, D. (2000). The status of evidence and outcomes in stages of change research. Health Education Research, 15, 707-718.

Manoj Sharma, MBBS, CHES, Ph.D. & Ashutosh Atri, MBBS, M.Ed. (candidate) Editor, Journal of Alcohol & Drug Education University of Cincinnati PO Box 210002, Cincinnati, OH 45221-0002