Acceptance and commitment therapy: cognitive fusion and personality functioning

341 Pages·2013·3.95 MB·English

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UNIVERSITY OF SOUTHAMPTON

FACULTY OF SOCIAL AND HUMAN SCIENCES

Psychology

Acceptance and Commitment Therapy: Cognitive Fusion and
Personality Functioning

by

Helen Bolderston

Thesis for the degree of Doctor of Philosophy

May 2013
UNIVERSITY OF SOUTHAMPTON

ABSTRACT

FACULTY OF SOCIAL AND HUMAN SCIENCES

PSYCHOLOGY

Doctor of Philosophy

ACCEPTANCE AND COMMITMENT THERAPY: COGNITIVE
FUSION AND PERSONALITY FUNCTIONING

by Helen Bolderston

Personality disorders (PDs) are common, chronic, mental health problems. The
majority of treatment outcome research, which has focused specifically on Borderline
PD, has provided substantial empirical support for Dialectical Behaviour Therapy
(DBT; Linehan, 1993), particularly in terms of self-harm reduction. Nevertheless,
DBT graduates can continue to experience poor personality functioning across PD
diagnostic categories, Axis I disorders, and restricted lives. Acceptance and
Commitment Therapy (ACT; Hayes, Strosahl, & Wilson, 1999), might be suitable as
a follow-up intervention for DBT graduates, to address their continued difficulties: to
date, however, there has been little empirical investigation of its utility in relation to
PD. This thesis was therefore designed to examine theoretical underpinnings of ACT
relevant to the development of an ACT intervention for DBT graduates.

Study 1 tested the performance of a new self-report measure of cognitive
fusion (CF), the Cognitive Fusion Questionnaire (CFQ), with a mental health sample,
including individuals with PD. CF is a key ACT concept, and the CFQ proved to be a
psychometrically sound measure of CF with people with mental health problems.
Study 2 used cross-sectional modelling to show that CF fully mediated the
relationships between two PD risk factors, negative affectivity and childhood trauma,
and personality functioning in adulthood. Study 3 used the CFQ to investigate the
behavioural correlates of CF. These findings strengthened the possibility that an
ACT-based intervention might prove effective in improving outcomes for DBT
graduates. To explore this further, Studies 4 and 5 were designed as very small-scale
uncontrolled treatment development trials for this population. Study 4 suggested that
ACT had a positive impact on engagement in life, but produced little improvement in
psychiatric symptomology. Study 5 tested a revised protocol, which yielded more
consistently positive findings, with improvements in both engagement in life and
psychiatric symptoms. These findings tentatively suggest that ACT may have a role
to play as a DBT follow-up intervention.
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TABLE OF CONTENTS

DECLARATION OF AUTHORSHIP ................................................................................. vii
ACKNOWLEDGEMENTS ................................................................................................. viii
CHAPTER I .................................................................................................................. 1
Personality Disorder ................................................................................................................ 1
1.1 Diagnosis ......................................................................................................................... 1
1.1.1 Comorbidity and Dimensionality in PDs ............................................................................... 2
1.2 Aetiology of PD .............................................................................................................. 4
1.3 Treatment of PD .............................................................................................................. 6
1.3.1 Psychosocial Treatment of PD ............................................................................................... 6
1.3.2. Behavioural and Cognitive Behavioural Psychotherapies .................................................... 7
1.3.2.1 Behaviour Therapy .............................................................................................................. 8
1.3.2.2 Cognitive Behaviour Therapy ............................................................................................. 9
1.3.2.3 Dialectical Behaviour Therapy .......................................................................................... 11
1.3.3 Psychodynamic and Interpersonal Psychotherapies ............................................................. 19
1.3.3.1 Cognitive Analytic Therapy .............................................................................................. 20
1.3.3.2 Schema Therapy ................................................................................................................ 21
1.3.3.3 Psychodynamic Psychotherapy ......................................................................................... 22
1.3.4 General Discussion of Psychosocial Treatment Literature .................................................. 24
CHAPTER II .............................................................................................................. 29
Behavioural and Cognitive Behavioural Psychotherapies ................................................. 29
2.1 First and Second Wave Behavioural and Cognitive Behavioural Psychotherapies ...... 29
2.2 Third Wave Psychotherapies ......................................................................................... 32
2.2.1 Acceptance and Commitment Therapy ................................................................................ 33
2.2.1.1 Relational Frame Theory ................................................................................................... 33
2.2.1.2 Psychological Inflexibility Model ..................................................................................... 36
2.2.1.3 ACT: Therapeutic Features ............................................................................................... 46
2.2.1.4 Evidence Supporting ACT: Outcome and Process Findings ............................................ 48
CHAPTER III ............................................................................................................. 53
Methodological Considerations ............................................................................................ 53
3.1 Preclinical or Theoretical Phase .................................................................................... 53
3.2 Phase I: Modelling ........................................................................................................ 55
3.2.1 Measurement ........................................................................................................................ 55
3.2.2 Model Building and Testing ................................................................................................. 64
3.3 Phase II: Exploratory Trial ............................................................................................ 73
3.3.1 Statistical Considerations in Small-Scale, Open Trials ........................................................ 74
3.3.2 RCTs .................................................................................................................................... 75
3.3.3 Statistical Considerations in RCTs ....................................................................................... 76
3.4 Phase III: Definitive RCT ............................................................................................. 78
3.5 Phase IV: Long-Term Implementation ......................................................................... 78
3.6 The Present Thesis ........................................................................................................ 80
CHAPTER IV ............................................................................................................. 83
Study 1. The Clinical Validation of a Self-Report Measure of Cognitive Fusion ............ 83
4.1 Introduction ................................................................................................................... 83
4.1.1 Cognitive Fusion .................................................................................................................. 83
4.1.2 Measurement of Cognitive Fusion ....................................................................................... 84
4.1.3 Cognitive Fusion Questionnaire ........................................................................................... 85
4.1.4 Present Study ........................................................................................................................ 88
4.2 Method .......................................................................................................................... 89
4.2.1 Participants ........................................................................................................................... 89
4.2.2 Materials ............................................................................................................................... 91
4.2.3 Procedure .............................................................................................................................. 94
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4.2.4 Analysis Plan ....................................................................................................................... 95
4.3 Results ........................................................................................................................... 95
4.3.1 Data Screening ..................................................................................................................... 95
4.3.2 Stage One: Item Characteristics, Distribution and Outliers ................................................ 96
4.3.3 Stage Two: Confirmatory Factor Analysis .......................................................................... 98
4.3.4 Stage Three: Reliability ..................................................................................................... 100
4.3.5 Sample Characteristics ...................................................................................................... 101
4.3.6 Concurrent, Convergent, and Divergent Validity .............................................................. 102
4.4 Discussion ................................................................................................................... 105
4.4.1 Study Findings ................................................................................................................... 105
4.4.2 Methodological Limitations .............................................................................................. 108
4.4.3. Future Research ................................................................................................................ 109
4.4.4 Summary ............................................................................................................................ 110
CHAPTER V ............................................................................................................ 111
Study 2. Modelling the Role of Cognitive Fusion in Relation to Personality
Functioning .......................................................................................................................... 111
5.1 Introduction ................................................................................................................. 111
5.1.1 Risk Factors for Poor Personality Functioning .................................................................. 112
5.1.2 The Role of Cognitive Fusion ........................................................................................... 112
5.1.3 Study Synopsis, Methodological and Design Considerations ........................................... 114
5.2 Method ........................................................................................................................ 115
5.2.1 Design ................................................................................................................................ 115
5.2.2 Participants ........................................................................................................................ 115
5.2.3 Materials ............................................................................................................................ 116
5.2.4 Procedure ........................................................................................................................... 118
5.2.5 Analysis Plan ..................................................................................................................... 119
5.3 Results ......................................................................................................................... 119
5.3.1 Stage One: Data Screening and Preliminary Analyses ...................................................... 119
5.3.2 Stage Two: Mediational Analyses ..................................................................................... 122
5.3.3 Stage Three. SEM Mediational Models ............................................................................ 125
5.4 Discussion ................................................................................................................... 129
5.4.1 Study Findings ................................................................................................................... 129
5.4.2 Methodological Limitations .............................................................................................. 132
5.4.3 Implications and Future Research ..................................................................................... 133
5.4.4 Summary ............................................................................................................................ 135
CHAPTER VI ........................................................................................................... 137
Study 3: An Investigation of the Behavioural Correlates of Cognitive Fusion ............. 137
6.1 Introduction ................................................................................................................. 137
6.1.1 Laboratory-Based Investigation of Cognitive Fusion ....................................................... 137
6.1.2 Cognitive Fusion and Experiential Avoidance .................................................................. 138
6.1.3 Measuring Experiential Avoidance ................................................................................... 140
6.1.4 Study Design, Aims, and Hypotheses ............................................................................... 142
6.2 Method ........................................................................................................................ 143
6.2.1 Participants ........................................................................................................................ 143
6.2.2 Materials ............................................................................................................................ 143
6.2.3 Procedure ........................................................................................................................... 145
6.2.4 Analysis Plan ..................................................................................................................... 146
6.3 Results ......................................................................................................................... 147
6.3.1 Stage One. Data Screening and Preliminary Analyses ...................................................... 147
6.3.2 Stage Two. Comparisons between view time for positively and negatively valenced
words. ......................................................................................................................................... 149
6.3.3 Stage Three. Relationship Between CFQ Score and Stimulus View Time. ...................... 149
6.3.4 Memory Data Analysis ...................................................................................................... 150
6.4 Discussion ................................................................................................................... 150
6.4.1 Study Findings ................................................................................................................... 150
6.4.2 Methodological Limitations .............................................................................................. 154
6.4.3 Implications and Future Research ..................................................................................... 156
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6.4.4. Summary ........................................................................................................................... 158

Chapter VII ............................................................................................................... 159
Study 4: Uncontrolled pilot development trial of an ACT-based group intervention for
post-DBT patients with poor personality functioning ...................................................... 159
7.1 Introduction ................................................................................................................. 159
7.1.1 DBT and PD ....................................................................................................................... 160
7.1.2 ACT Processes and Personality Functioning ..................................................................... 160
7.1.3 ACT-Based Interventions for PD ....................................................................................... 161
7.1.4 Methodological Considerations .......................................................................................... 162
7.2 Method ........................................................................................................................ 164
7.2.1 Design ................................................................................................................................ 164
7.2.2 Participants ......................................................................................................................... 164
7.2.3 Materials ............................................................................................................................. 168
7.2.4 Procedure ............................................................................................................................ 171
7.2.5 Analysis Plan ...................................................................................................................... 180
7.3 Results ......................................................................................................................... 180
7.3.1 Stage One. Preliminary Analysis and Participant Characteristics ...................................... 180
7.3.2 Stage Two. Group statistical analyses ................................................................................ 181
7.3.3 Stage Three. Reliable and Clinically Significant Individual Changes ............................... 183
7.3.4 Stage Four. Data Not Analysed Using the RCI Methodology ........................................... 188
7.4 Discussion ................................................................................................................... 191
7.4.1 Study Findings ................................................................................................................... 191
7.4.2 Methodological Limitations ............................................................................................... 197
7.4.3 Protocol Limitations ........................................................................................................... 198
7.4.3 Implications and Future Research ...................................................................................... 199
7.4.4 Summary ............................................................................................................................ 200
CHAPTER VIII ........................................................................................................ 201
Study 5: A Second Uncontrolled Pilot Development Trial of an ACT-based Group
Intervention for Post-DBT Patients with Poor Personality Functioning ....................... 201
8.1 Introduction ................................................................................................................. 201
8.2 Method ........................................................................................................................ 201
8.2.1 Design ................................................................................................................................ 201
8.2.2 Participants ......................................................................................................................... 201
8.2.3 Materials ............................................................................................................................. 204
8.2.4 Procedure ............................................................................................................................ 206
8.2.5 Analysis Plan ...................................................................................................................... 207
8.3 Results ......................................................................................................................... 207
8.3.1 Stage 1. Preliminary Analysis and Participant Characteristics .......................................... 207
8.3.2 Stage Two. Group Statistical Analyses and Effect Sizes ................................................... 209
8.3.3 Stage Three. Individual Participant RCIs ........................................................................... 212
8.3.4 Stage Four. Data Not Analysed Using the RCI Methodology ........................................... 217
8.4 Discussion ................................................................................................................... 221
8.4.1 Study Findings ................................................................................................................... 221
8.4.2 Methodological Limitations ............................................................................................... 227
8.4.3 Implications and Future Research ...................................................................................... 227
8.4.4 Summary ............................................................................................................................ 230
CHAPTER IX ........................................................................................................... 231
General Discussion .............................................................................................................. 231
9.1 Main Findings ............................................................................................................. 232
9.1.1 Analogue Research ............................................................................................................. 232
9.1.2 Applied research ................................................................................................................. 233
9.1.4 Main Strengths ................................................................................................................... 235
9.1.5 Main Limitations ................................................................................................................ 236
9.2 Implications and Suggestions for Future Research ..................................................... 237
9.2.1 CF, the CFQ, and the ACT Model ..................................................................................... 237
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9.2.3 Additional Mediators of Poor Personality Functioning ..................................................... 238
9.2.4 Behavioural Measures of Psychological Processes ........................................................... 239
9.2.5 Psychosocial Treatment of Poor Personality Functioning ................................................. 239
9.3 Concluding Remarks ................................................................................................... 240
APPENDICES .......................................................................................................... 242
Appendix A: Summary of principal methodological characteristics and results for all
cognitive behavioural therapies RCTs for PD, organised by intervention type .................... 242
Appendix B: Cognitive Fusion Questionnaire ...................................................................... 261
Appendix C: Brief Demographics Questionnaire ................................................................. 262
Appendix D: Study 1 Research Ethics Committee Approval Letter ..................................... 263
Appendix E: Study 1 consent form, participant information sheet and debrief sheet .......... 264
Appendix F: Public access websites where Study 2 was hosted ........................................... 270
Appendix G: Study 2 demographic questionnaire/participant information/debrief sheet ..... 271
Appendix H: List of 48 self-referential adjectives used in Study 3 ...................................... 276
Appendix I: Study 3 Brief Demographics Questionnaire ..................................................... 277
Appendix J: Study 3 consent form, participant information sheet and debrief sheet ............ 278
Appendix K: Study 4: Details of protocol development ....................................................... 282
Appendix L: Studies 4 and 5 Research Ethics Committee Approval Letter ......................... 284
Appendix M: Studies 4 and 5 consent form, participant information sheet, and GP/CMHT
information sheet ................................................................................................................... 285
Appendix N: Study 4: Details of treatment protocol ............................................................. 294
Appendix O: Life Activities Schedule .................................................................................. 297
REFERENCES ......................................................................................................... 300

LIST OF TABLES

Chapter III
Table 3.1 Measurement Methodologies and Data Output................................. 56

Chapter IV
Table 4.1 Correlations Between the CFQ and Measures of Relevant
Variables........................................................................................... 88
Table 4.2 Descriptive Data for CFQ Items....................................................... . 97
Table 4.3 Skew and Kurtosis Data for CFQ Items............................................ 97
Table 4.4 Fit Indices for CFA Comparing Four Factor Models for the CFQ.. . 100
Table 4.5 Cronbach’s α Coefficient for the CFQ, for Clinical and Non-
Clinical Samples.............................................................................. . 101
Table 4.6 Normative data for the CFQ for clinical and non-clinical samples.. 102
Table 4.7 Correlations Between the CFQ and Measures of Psychopathology.. 103
Table 4.8 Correlations Between the CFQ and Measures of Relevant
Variables........................................................................................... . 104

Chapter V
Table 5.1 Demographic Information................................................................ . 116
Table 5.2 Skew and kurtosis data for all study variables................................. . 120
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Table 5.3 Means, Standard Deviation, and Internal Reliability Values for All
Study Variables................................................................................. 121
Table 5.4 Inter-Correlations Between SIPP Subscales..................................... 122
Table 5.5 Bivariate Correlations Between Study Variables.............................. 122
Table 5.6 Tests of CF as a Mediator of Significant Associations between IVs
and DV.............................................................................................. 125
Table 5.7 Fit Indices for Four Mediation Models............................................. 126

Chapter VI
Table 6.1 Demographic Information................................................................ . 144
Table 6.2 Skew and Kurtosis Data for All Study Variables............................. . 148
Table 6.3 Means and Standard Deviations for All Study Variables................. . 148
Table 6.4 Paired Sample t Tests Comparing Positive and Negative View
Time.................................................................................................. . 149
Table 6.5 Bivariate Correlations between CFQ Score and View Time........... . 150

Chapter VII
Table 7.1 Demographics and Baseline Statistics.............................................. . 167
Table 7.2 PD Baseline Statistics....................................................................... . 168
Table 7.3 Weekly Session Topics.................................................................... . 176
Table 7.4 Means and Standard Deviations for All Study Measures................ . 182
Table 7.5 Friedman ANOVAs for Repeated Measures at Pre, Post, and
Follow-Up......................................................................................... 183
Table 7.6 Reliable and Clinically Significant Individual Changes................... 185
Table 7.7 Changes in PD Diagnoses Based on 12-Month SCID-II Prevalence 189
Table 7.8 Participant Self-Harming Behaviour................................................. 190

Chapter VIII
Table 8.1 Demographics and Baseline Statistics............................................... 203
Table 8.2 PD Baseline Statistics....................................................................... . 204
Table 8.3 Means and Standard Deviations for All Study Measures................ . 208
Table 8.4 Friedman ANOVAs for Repeated Measures at Pre, Post, and
Follow-Up........................................................................................ . 210
Table 8.5 Effect Sizes....................................................................................... . 211
Table 8.6 Reliable and Clinically Significant Individual Changes................... 214
Table 8.7 Changes in PD Diagnoses Based on 12-Month SCID-II Prevalence 219
Table 8.8 Participant Self-Harming Behaviour................................................ . 220