Personality Disorders in Adolescent Outpatients: a Cross-Sectional Study of Prevalence, Comorbidity and Quality of Life
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Personality Disorders in Adolescent Outpatients: a Cross-sectional Study of Prevalence, Comorbidity and Quality of Life Hans Ole Korsgaard The Nic Waal Institute, Lovisenberg Diakonale Hospital, Oslo, Norway Institute of Clinical Medicine, Faculty of Medicine, University of Oslo © Hans Ole Korsgaard, 2017 Series of dissertations submitted to the Faculty of Medicine, University of Oslo ISBN 978-82-8333-336-7 All rights reserved. No part of this publication may be reproduced or transmitted, in any form or by any means, without permission. Cover: Hanne Baadsgaard Utigard. Print production: Reprosentralen, University of Oslo. Table of contents Acknowledgements ........................................................................................................................... 1 Abbreviations .................................................................................................................................... 3 List of papers .................................................................................................................................... 4 Summary ........................................................................................................................................... 5 1. Introduction .................................................................................................................................. 8 1.1 Diagnosing personality disorders in adolescence ................................................................ 8 1.2 Personality disorders and quality of life ............................................................................ 13 1.3 ADHD, personality disorders and Axis I comorbidity ...................................................... 16 1.4 Substance use disorders, personality disorders, and Axis I comorbidity .......................... 20 2. Objectives .................................................................................................................................... 23 3. Material and methods ................................................................................................................ 24 3.1 Research on prevalence using cross-sectional study designs ............................................ 24 3.2 Participants ........................................................................................................................ 24 3.3 Inclusion/exclusion criteria ............................................................................................... 25 3.4 Missing data ...................................................................................................................... 25 3.5 Measures ............................................................................................................................ 26 3.5.1 DSM-IV and DSM-5 ...................................................................................................... 26 3.5.2 Personality disorders ...................................................................................................... 28 3.5.3 Axis I disorders .............................................................................................................. 29 3.5.4 Quality of life ................................................................................................................. 30 3.6 Procedures and assessment ................................................................................................ 30 3.7 Statistics ............................................................................................................................ 31 3.7.1 Validity ........................................................................................................................... 31 3.7.2 Reliability ....................................................................................................................... 32 3.7.3 Linear regression analysis .............................................................................................. 33 3.7.4 Odds ratios, logistic regression, and confidence intervals ............................................. 34 3.7.5 Confounding ................................................................................................................... 34 3.7.6 Statistical analyses .......................................................................................................... 35 3.8 Ethical aspects of the study ............................................................................................... 37 4. Summary of results .................................................................................................................... 38 4.1 Paper I ............................................................................................................................... 38 4.2 Paper II .............................................................................................................................. 40 4.3 Paper III ............................................................................................................................. 41 5. Discussion .................................................................................................................................... 43 5.1 Discussion of the main results – Discussion of methods .................................................. 43 5.1.1 Prevalence and gender distribution of personality disorders in the sample ................... 44 5.1.2 Personality disorders and quality of life ......................................................................... 45 5.1.3 ADHD, Axis I comorbidity, and personality disorders .................................................. 45 5.1.4 Personality disorders and substance use disorders ......................................................... 49 5.2 Strengths and limitations of the present study .................................................................. 50 6. Clinical implications of the main findings and future research ............................................. 51 6.1 Implications for clinical practice ....................................................................................... 51 6.2 Implications for future research ........................................................................................ 51 6.3 Conclusions ....................................................................................................................... 53 7. References ................................................................................................................................... 55 8. Papers Paper I Paper II Paper III Acknowledgements The study that supplied the data for this thesis was conducted from 2005 - 2007 at The Nic Waal Institute, Lovisenberg Diakonale Hospital. The project has been financially supported by grants from the South-Eastern Norway Regional Health Authority, the Centre for Child and Adolescent Mental Health, Eastern and Southern Norway, and by my employer Lovisenberg Diakonale Hospital. I would like to thank my many clinical supervisors, who throughout the years have been inspiring role models and have nurtured and encouraged my interest in the diverse clinical manifestations of personality disorders. I started my residential work in child and adolescent psychiatry in 1998. It soon became clear to me that the clinical phenomenon of personality disorder does not honor the arbitrary diagnostic age boundary between adolescence and adulthood that we clinicians tend to set. I was fortunate to be introduced to Professor Svenn Torgersen, who with his immense experience in this research field helped me design the study protocol in a methodologically sound way. I have had many inspiring talks with Professor Torgersen, and I consider it a great privilege to have made his acquaintance. I would especially like to thank Assistant Professor Randi Ulberg, who has been my main supervisor since April 2014. As a hard-working and highly experienced scientist and clinician, she has generously shared her knowledge about scientific thinking and publishing with me. She has been both challenging and encouraging in a most helpful way. I cannot overstate her importance for the completion of the present work. The support of statistician Tore Wentzel-Larsen, M.Sc., who is senior researcher at the Norwegian Centre for Violence and Traumatic Stress Studies as well as at the Centre for Child and Adolescent Mental Health, Eastern and Southern Norway, has been an absolute prerequisite for the completion of the project. With his extensive knowledge of statistics and vast experience in scientific publishing, he has not only provided the study with methodologically solid statistical analyses; he has also managed the challenging task of teaching me statistical methods that are relevant for the present study. I am very grateful to him for helping me with the formulation of hypotheses and for the critical proof-reading of all article drafts. I am also greatly indebted to Mette Bengtson, Head of The Nic Waal Institute, for her generous support that has made the completion of the present work possible. I am equally 1 grateful to Dr. Bjørn Holm, Ph.D., former Head of the Research Dept. at Lovisenberg Diakonale Hospital, for his never-failing faith in the project, and to Bjørg Grova, former Head of the Research Dept. at The Nic Waal Institute, for her enthusiasm and encouragement in the initial phases of the project. I would like to thank all patients who participated in the study. They invested some of their time to be