A test of the assumptions of the transtheoretical model in a post-traumatic stress disorder population

Abstract

Prior reports suggest an ambivalence regarding treatment in individuals with Post-Traumatic Stress Disorder (PTSD). A model that accommodates such ambivalence is the Transtheoretical Model of Behavior Change (TTM, also known as the Stages-of-Change Model). Fifty veterans presenting for treatment completed self-report measures (94% response rate) that assessed disorder variables and constructs relating to the TTM. While the relationships between the components of each specific construct were found to be consistent with the findings of other studies and a number of predicted relationships between variables were confirmed, many results were inconsistent with the TTM. Notwithstanding questions about the suitability of the self-report measures, the unique characteristics of the veteran sample and the small sample size, the results suggest that the assumptions of the TTM were not met in veterans with PTSD.

Prediction of Outcome for Veterans with Post-Traumatic Stress Disorder Using Constructs from the Transtheoretical Model of Behaviour Change

“…A previous study using this same population found that although the TTM constructs appeared to be internally consistent, many of the predicted relationships between the TTM variables were not found [18]. For example, contrary to the model, changes over time in assigned SOC and RTC-C were not related to POC.…”

“…Changes in RTC-C and behavioural processes over time, but not changes in assigned SOC, were predictive of changes in symptom severity over time. The SOC construct may have had reduced applicability in the current sample because participants generally scored highly across each of the contemplation, action, and maintenance SOC scales [18]. Therefore, participants may not have been in distinct SOCs, but rather, in several SOCs concurrently for different behaviours.…”

“…Behavioural, but not cognitive/experiential, process usage was also found to predict outcome. Cognitive/experiential processes have been found to be stable across SOC (excluding pre-contemplators) in trauma patients [18], thus suggesting that usage is independent of whether or not people describe themselves as actively changing or trying to change. In addition, it is possible that combining cognitive and affective processes may have diluted their predictive utility.…”

“…In terms of the predictive utility of TTM variables at specific points in time, we found that only initial SOC was predictive of change in symptom scores over treatment and follow up. A possible viewpoint, in light of the results of Rooney et al [18], is that the use of categorical stages of change has limitations in a multifaceted disorder such as PTSD. We must also acknowledge a possible cohort effect, in which the TTM variables were strongly influenced by peers attending the same treatment group.…”

Effect of a motivation enhancement intervention on veterans’ engagement in PTSD treatment.

“…In our clinical experience, veterans are rarely ambivalent about acknowledgment of the PTSD diagnosis. Therefore, it is not surprising that Rooney et al (2005) did not find support for the application of the transtheoretical model’s stages of change to PTSD among combat veterans because they assessed readiness to change for three broad PTSD diagnostic symptom categories in general.…”