Motivation to Change and Anorexia Nervosa: Relation between Expressions of Motivation to Change and Outcome in Psychotherapy
Degree GrantorUniversity of Canterbury
Degree NameMaster of Arts
Use of language is thought to be particularly important when considering an individual’s motivation to change. The present thesis has expanded on existing knowledge of the relation between motivation to change and psychotherapy outcome for individuals with anorexia nervosa. This was accomplished by rating 148 audiotaped psychotherapy sessions with four measures of motivation to change. Data were derived from an existing clinical trial of three types of psychotherapy (Cognitive-Behaviour Therapy, Interpersonal Therapy, and Specialist Supportive Clinical Management). Three sessions were rated for each of the 53 participants who received up to twenty sessions of psychotherapy, early (sessions 1-5, middle (sessions 6-14), and late (sessions 15-20). Participant expressions of motivation to change were analysed across sessions, within sessions (beginning, mid, and end intervals), by change talk type, and therapy type for those with good and poor outcomes. Resistance and readiness to change, positive psychotherapy process, and readiness to recover from anorexia nervosa were also examined.
The main findings were significantly more positive change talk expressed in the beginning than mid and end therapy intervals and significantly more negative change talk expressed in the beginning than end therapy interval and in the mid than end interval. When change talk type was examined, a significant difference in the ratio of positive to negative change talk expressed between change talk types was found.
Results from other motivation measures indicated that readiness to change was expressed significantly more frequently in the middle and late than early phase of therapy. There were higher levels of positive process in psychotherapy in the late than early phase of therapy, and higher levels in those with good than poor outcomes. There were significantly higher levels of readiness to recover from anorexia nervosa expressed in the middle and late phases of therapy than in the early phase, and higher levels in those with good than poor outcomes. Limitations to these results include a modest sample size, rater biases, and lack of reliability measures. Notwithstanding these limitations, the present study has produced several potentially important findings that merit further investigation.