Inhibition and executive functioning in trichotillomania [Elektronische Ressource] : a comparison with an obsessive-compulsive disorder group and a healthy control group / vorgelegt von Antje Bohne

INHIBITION AND EXECUTIVE FUNCTIONING IN TRICHOTILLOMANIA
A Comparison With an Obsessive-Compulsive Disorder Group and a Healthy Control Group


Dissertation
zur
Erlangung des Doktorgrades
der Naturwissenschaften
(Dr. rer. nat.)


dem
Fachbereich Psychologie
der Philipps-Universität Marburg
vorgelegt von
Antje Bohne
aus Gütersloh


Marburg/Lahn 2003
1
Table of Contents

List of Tables and Figures .............................................................................................................5
Acknowledgments.........................................................................................................................6
Zusammenfassung.........7
Abstract .......................................................................................................................................15

1 General Introduction...............................................................................................................22
1.1 Trichotillomania: Clinical Picture, Etiology, and Treatment........................................22
1.2 Impulse-Control Disorder or Obsessive-Compulsive Spectrum Disorder? ..................25
1.3 Rationale for the Current Investigation.........................................................................27
2 General Methods.....................................................................................................................30
2.1 Participants....................................................................................................................30
2.2 Measures.......................................................................................................................31
2.3 Materials........................................................................................................................34
2.4 Procedures.....................................................................................................................34
3 Study 1: Motor Inhibition in Trichotillomania and Obsessive-Compulsive Disorder ...........37
3.1 Abstract......38
3.2 Introduction...................................................................................................................39
3.3 Methods.........................................................................................................................43
3.3.1 Participants........................................................................................................43
3.3.2 Measures............................................................................................................45
3.3.3 Procedure...........................................................................................................46
3.3.4 Statistics47
3.4 Results...........................................................................................................................48
2
3.4.1 Symptom Severity, Verbal Intellectual Abilities, and Attention Span..............48
3.4.2 Motor Inhibition................................................................................................49
3.5 Discussion.....................................................................................................................52
4 Study 2: Cognitive Inhibition in Trichotillomania and Obsessive-Compulsive Disorder......62
4.1 Abstract.........................................................................................................................63
4.2 Introduction...................................................................................................................64
4.3 Methods.........................................................................................................................70
4.3.1 Participants........................................................................................................70
4.3.2 Measures............................................................................................................72
4.3.3 Procedure...........................................................................................................72
4.3.4 Statistics74
4.4 Results.......74
4.4.1 Symptom Severity, Verbal Intellectual Abilities, and Attention Span..............74
4.4.2 Free Recall.........................................................................................................75
4.4.3 Recognition.......................................................................................................77
4.4.4 Emotionality Rating..........................................................................................79
4.5 Discussion.....................................................................................................................81
5 Study 3: Executive Functioning in Trichotillomania and Obsessive-Compulsive Disorder..93
5.1 Abstract.........................................................................................................................94
5.2 Introduction...................................................................................................................95
5.3 Methods.........................................................................................................................98
5.3.1 Participants........................................................................................................98
5.3.2 Measures..........................................................................................................100
5.3.3 Neuropsychological Test Battery ....................................................................101
5.3.4 Procedure.........................................................................................................103
3
5.3.5 Statistics..........................................................................................................104
5.4 Results.........................................................................................................................104
5.4.1 Symptom Severity, Verbal Intellectual Abilities, and Attention Span............104
5.4.2 Visuospatial Ability and Memory ...................................................................105
5.4.3 Executive Functioning.....................................................................................106
5.4.4 Post Hoc Analyses in OCD .............................................................................108
5.5 Discussion...................................................................................................................109
6 General Discussion...............................................................................................................119
6.1 Etiology and Maintenance of TTM120
6.2 Classification of TTM.................................................................................................122
6.3 Conclusions on Treatment ..........................................................................................124
6.4 Limitations..................................................................................................................126
6.5 Concluding Remarks...................................................................................................126
7 References ............................................................................................................................128
8 Appendix..............................................................................................................................146
8.1 Appendix A: Recruitment Information Used..............................................................147
8.2 Appendix B: The Massachusetts General Hospital Hairpulling Scale (MGH-HS) ....148
8.3 Appendix C: Test Sequences Used .............................................................................150
8.4 Appendix D: Instruction Used in the GoNogo Experiment........................................151
8.5 Appendix E: Word Lists Used in the Directed Forgetting Experiment ......................152
8.6 Appendix F: Instruction Used in thorgetting Experiment .......................153
9 Curriculum Vitae..................................................................................................................155

4
List of Tables and Figures

Tables
2.1 Overview of the Potential Course of a Test Session ............................................................36
3.1 GoNogo Errors as a Function of Group and Error Type......................................................59
3.2 GoNogo Errors and Demographic Variables as a Function of Trichotillomania Subtype...60
4.1 Correct Free Recall of Words as a Function of Group, Instruction and Word Type............89
4.2 Correct Recognition of Words as a Functinstruction and Word Type ..........90
4.3 Emotionality Rating of Words as a Function of Group, Inpe ..........91
5.1 Group Means and Standard Deviations in Visuospatial and Memory Tasks.....................116
5.2 Group Means and Standard Deviations in Executive Functioning Tasks..........................117

Figures
3.1 Scatter Plots With Trend Line of Speed by Accuracy of Performance in the GoNogo .......61
4.1 Emotionality Rating of Words as a Function of Group and Free Recall Status...................92

5
Acknowledgments

I am very