- Title
- Therapist fidelity to contrasting psychological treatments for young people at ultra-high risk of developing psychosis
- Creator
- Bell, Katrina
- Resource Type
- thesis
- Date
- 2009
- Description
- Professional Doctorate - Doctor of Clinical Psychology
- Description
- Background: It has been demonstrated recently that it is possible to identify individuals suffering from ‘at-risk mental states’ (ARMS) who, in the absence of treatment, are likely to develop a psychotic disorder within a year. This increase in detection ability has increased confidence that preventative interventions in psychotic disorders are a realistic proposition in clinical settings. Only three randomised controlled trials of interventions for the at-risk population have been published to date, with promising results. Two of them suggest that it is possible to prevent, or at least delay, transition to psychosis utilising Cognitive Behavioural Therapy (CBT). However, these trials have not adequately addressed treatment fidelity which is vital in allowing accurate and valid conclusions to be drawn from treatment outcome research. Method: The Detection, Evaluation and Psychological Therapy (DEPTh) project, a single blind randomised controlled trial, was designed to compare the effectiveness of CBT and a control psychotherapy, Non Directive Reflective Listening (NDRL), in ameliorating ARMS and delaying or preventing transition to psychosis. Treatment fidelity (adherence and competence) to both interventions was assessed using three established measures: The Cognitive Therapy Scale: CTS; The Cognitive Therapy for Psychosis Scale: CTS-Psy; and the Working Alliance Inventory Shortened Observer Rated Version: WAI-O-S. In addition, a new measure, the Cognitive Therapy for At Risk Populations Adherence Scale (CTARPAS) was developed, piloted and revised by the investigator and colleagues to rate therapist adherence to the French and Morrison (2004) model of cognitive therapy for individuals at high risk of developing psychosis that was used to guide the CBT intervention in the DEPTh project. 55 sessions (35 of the CBT intervention and 23 of the NDRL intervention) from a total of 21 participants were rated for fidelity. Results: The agreement between two independent raters was very high on most of the items of the CTARPAS, CTS, CTS-Psy and the WAI-O-S, for both the CBT and the NDRL interventions. Therapists delivering the CBT intervention had low mean scores on the CTARPAS which was most likely due to participants rarely discussing psychotic or attenuated psychotic symptoms. Therapists delivering the CBT intervention were rated as highly competent on the CTS. Therapists delivering the NDRL intervention were rated as adherent and competent. There were significant variations in CTARPAS ratings in the CBT intervention over the stages of therapy (early, middle and late), but there was no variation in ratings on any other measure in either intervention over the stages of therapy. High correlations were found between the CTS and the CTS-Psy. Discussion: This was the first study to investigate treatment fidelity in a randomised controlled trial of CBT and a control psychotherapy for the at-risk population. A new measure, the CTARPAS, was developed and used in this study and has the potential to be utilised in future investigations. The overall results from this study add significantly to the knowledge base in the field of indicated prevention and highlight the importance of treatment fidelity in treatment outcome research.
- Subject
- treatment fidelity; psychosis; at-risk mental states
- Identifier
- http://hdl.handle.net/1959.13/803286
- Identifier
- uon:6352
- Rights
- Copyright 2009 Katrina Bell
- Language
- eng
- Full Text
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| View Details Download | ATTACHMENT02 | Thesis | 673 KB | Adobe Acrobat PDF | View Details Download |