Publications 2025

Kildahl AN, Langjord T, Pedersen G, Hove O, Urnes Ø, Torgersen T, Eikenæs IHU, Kvarstein EH (2025)
Screening for autism in psychiatric inpatients with severe self-harm - results from the Extreme Challenges research project
Nord J Psychiatry, 79 (4), 303-313
DOI 10.1080/08039488.2025.2497820, PubMed 40319453

Sayar H, Wilberg T, Eikenæs IU, Ekberg A, Leitemo K, Morken KTE, Oftedal E, Omvik S, Ulvestad DA, Pedersen G, Kvarstein EH (2025)
Improvement of alexithymia in patients treated in mental health services for personality disorders: a longitudinal, observational study
Front Psychiatry, 16, 1558654
DOI 10.3389/fpsyt.2025.1558654, PubMed 40206651

Sveen CA, Pedersen G, Wilberg T, Kvarstein EH (2025)
The societal costs of avoidant personality disorder
Personal Ment Health, 19 (1), e1644
DOI 10.1002/pmh.1644, PubMed 39572388

Publications 2024

Breivik Øvstebø R, Pedersen G, Wilberg T, Røssberg JI, Johnsen Dahl HS, Kvarstein EH (2024)
Countertransference, alliance, and outcome in the treatment of patients with personality disorder: a longitudinal naturalistic study
Front Psychiatry, 15, 1490056
DOI 10.3389/fpsyt.2024.1490056, PubMed 39777194

Eikeseth FF, Pedersen G, Hummelen B, Sütterlin S, Stubhaug A, Kvarstein EH, Kvarstein G (2024)
Pain prevalence rates and the mediating role of negative affect in adults referred to personality disorder treatment: A cross-sectional study
J Pain, 26, 104724
DOI 10.1016/j.jpain.2024.104724, PubMed 39481671

Langjord T, Pedersen G, Bovim T, Bremer K, Christensen TB, Hove O, Kildahl AN, Mork E, Norheim AB, Ramleth RK, Romm KL, Siqveland J, Schønning T, Stänicke LI, Torgersen T, Pettersen MS, Tveit T, Urnes Ø, Walby FA, Kvarstein EH (2024)
Evaluation of health services and treatment alliance among extensively hospitalized patients due to severe self-harm - results from the Extreme Challenges project
Nord J Psychiatry, 78 (7), 591-602
DOI 10.1080/08039488.2024.2376162, PubMed 39126325

Ulvestad DA, Johansen MS, Kvarstein EH, Pedersen G, Wilberg T (2024)
Minding mentalizing - convergent validity of the Mentalization Breakdown Interview
Front Psychiatry, 15, 1380532
DOI 10.3389/fpsyt.2024.1380532, PubMed 38974920

Ulvestad DA, Johansen MS, Kvarstein EH, Pedersen G, Wilberg T (2024)
Corrigendum: Minding mentalizing - convergent validity of the Mentalization Breakdown Interview
Front Psychiatry, 15, 1479612
DOI 10.3389/fpsyt.2024.1479612, PubMed 39234622

Publications 2023

Langjord T, Pedersen G, Bovim T, Christensen TB, Eikenæs IU, Hove O, Kildahl AN, Mork E, Norheim AB, Ramleth RK, Ringen PA, Romm KL, Siqveland J, Schønning T, Stänicke L, Torgersen T, Pettersen M, Tveit T, Urnes Ø, Walby F, Kvarstein EH (2023)
Mental health disorders, functioning and health-related quality of life among extensively hospitalized patients due to severe self-harm - results from the Extreme Challenges project
Front Psychiatry, 14, 1258025
DOI 10.3389/fpsyt.2023.1258025, PubMed 37920539

Paap MCS, Pedersen G, Kvarstein E, Hummelen B (2023)
Evaluating the Construct Validity of the Norwegian Version of the Level of Personality Functioning Scale - Brief Form 2.0 in a Large Clinical Sample
J Pers Assess, 106 (1), 49-59
DOI 10.1080/00223891.2023.2182694, PubMed 36897004

Sveen CA, Pedersen G, Hummelen B, Kvarstein EH (2023)
Personality disorders: the impact of severity on societal costs
Eur Arch Psychiatry Clin Neurosci, 275 (1), 181-192
DOI 10.1007/s00406-023-01715-6, PubMed 37991536

Wilberg T, Pedersen G, Bremer K, Johansen MS, Kvarstein EH (2023)
Combined group and individual therapy for patients with avoidant personality disorder-A pilot study
Front Psychiatry, 14, 1181686
DOI 10.3389/fpsyt.2023.1181686, PubMed 37215654

Publications 2022

Faerden A, Rosenqvist C, Håkansson M, Strøm-Gundersen E, Stav Å, Svartsund J, Røssæg T, Davik N, Kvarstein E, Pedersen G, Dieset I, Nyrud AQ, Weedon-Fekjær H, Kistorp KM (2022)
Environmental Transformations Enhancing Dignity in an Acute Psychiatric Ward: Outcome of a User-Driven Service Design Project
HERD, 16 (2), 55-72
DOI 10.1177/19375867221136558, PubMed 36567605

Nysaeter TE, Hummelen B, Christensen TB, Eikenaes IU, Selvik SG, Pedersen G, Bender DS, Skodol AE, Paap MCS (2022)
The Incremental Utility of Criteria A and B of the DSM-5 Alternative Model for Personality Disorders for Predicting DSM-IV/DSM-5 Section II Personality Disorders
J Pers Assess, 105 (1), 111-120
DOI 10.1080/00223891.2022.2039166, PubMed 35285763

Pedersen G, Wilberg T, Hummelen B, Hartveit Kvarstein E (2022)
The Norwegian network for personality disorders - development, contributions and challenges through 30 years
Nord J Psychiatry, 77 (5), 512-520
DOI 10.1080/08039488.2022.2147995, PubMed 36409693

Ulvestad DA, Selsbakk Johansen M, Hartveit Kvarstein E, Pedersen G, Wilberg T (2022)
A borderline focused Reflective Functioning measure - Interrater reliability of the Mentalization Breakdown Interview
Nord J Psychiatry, 77 (4), 360-366
DOI 10.1080/08039488.2022.2123040, PubMed 36244024

Zahl KE, Pedersen G, Eikenaes IU, Stänicke LI, Wilberg T, Baltzersen ÅL, Pettersen MS, Hummelen B, Arnevik E, Johansen MS, Hartveit Kvarstein E (2022)
Avoidant and borderline personality disorder patients during the first Covid-19 wave in Norway - a survey-based comparison of therapy changes and patients' accommodations
Nord J Psychiatry, 77 (4), 336-344
DOI 10.1080/08039488.2022.2110614, PubMed 35984379

Publications 2021

Hartveit Kvarstein E, Zahl KE, Stänicke LI, Pettersen MS, Baltzersen ÅL, Johansen MS, Eikenæs IU, Hummelen B, Wilberg T, Ajo Arnevik E, Pedersen G (2021)
Vulnerability of personality disorder during COVID-19 crises: a multicenter survey of mental and social distress among patients referred to treatment
Nord J Psychiatry
DOI 10.1080/08039488.2021.1942980, PubMed 34369842

Kvarstein EH, Antonsen BT, Klungsøyr O, Pedersen G, Wilberg T (2021)
Avoidant personality disorder and social functioning: A longitudinal, observational study investigating predictors of change in a clinical sample
Personal Disord, 12 (6), 594-605
DOI 10.1037/per0000471, PubMed 33507789

Kvarstein EH, Zahl KE, Stänicke LI, Pettersen MS, Baltzersen ÅL, Johansen MS, Eikenaes IU, Arnevik EA, Hummelen B, Wilberg T, Pedersen G (2021)
Vulnerability of personality disorder during the Covid-19 crises - a multicenter survey of treatment experiences among patients referred to treatment
Nord J Psychiatry, 76 (1), 52-63
DOI 10.1080/08039488.2021.1934110, PubMed 34126854

Pedersen G, Kvarstein EH, Wilberg T, Folmo EJ, Burlingame GM, Lorentzen S (2021)
The Group Questionnaire (GQ)-Psychometric Properties Among Outpatients With Personality Disorders
Group Dyn.-Theory Res. Pract.
DOI 10.1037/gdn0000176

Pedersen G, Normann-Eide E, Eikenaes IU, Kvarstein EH, Wilberg T (2021)
Psychometric evaluation of the Norwegian Toronto Alexithymia Scale (TAS-20) in a multisite clinical sample of patients with personality disorders and personality problems
J Clin Psychol, 78 (6), 1118-1136
DOI 10.1002/jclp.23270, PubMed 34716595

Paap MCS, Heltne A, Pedersen G, Germans Selvik S, Frans N, Wilberg T, Hummelen B (2021)
More is more: Evidence for the incremental value of the SCID-II/SCID-5-PD specific factors over and above a general personality disorder factor
Personal Disord, 13 (2), 108-118
DOI 10.1037/per0000426, PubMed 33600207

Publications 2020

Hummelen B, Braeken J, Buer Christensen T, Nysaeter TE, Germans Selvik S, Walther K, Pedersen G, Eikenaes I, Paap MCS (2020)
A Psychometric Analysis of the Structured Clinical Interview for the DSM-5 Alternative Model for Personality Disorders Module I (SCID-5-AMPD-I): Level of Personality Functioning Scale
Assessment, 28 (5), 1320-1333
DOI 10.1177/1073191120967972, PubMed 33155489

Kvarstein EH, Folmo E, Antonsen BT, Normann-Eide E, Pedersen G, Wilberg T (2020)
Social Cognition Capacities as Predictors of Outcome in Mentalization-Based Treatment (MBT)
Front Psychiatry, 11, 691
DOI 10.3389/fpsyt.2020.00691, PubMed 32792996

Paap MCS, Hummelen B, Braeken J, Arnevik EA, Walderhaug E, Wilberg T, Berghuis H, Hutsebaut J, Pedersen G (2020)
A multi-center psychometric evaluation of the Severity Indices of Personality Problems 118 (SIPP-118): Do we really need all those facets?
Qual Life Res, 30 (2), 567-575
DOI 10.1007/s11136-020-02654-8, PubMed 33029679

Publications 2019

Arnevik EA, Pedersen G, Walderhaug E, Lien I, Wilberg T, Hummelen B (2019)
Measuring Personality Problems in Patients With Substance Use Disorders: A Cross-Sample Validation
J Dual Diagn, 15 (4), 324-332
DOI 10.1080/15504263.2019.1668583, PubMed 31571533

Buer Christensen T, Eikenaes I, Hummelen B, Pedersen G, Nysæter TE, Bender DS, Skodol AE, Selvik SG (2019)
Level of personality functioning as a predictor of psychosocial functioning-Concurrent validity of criterion A
Personal Disord, 11 (2), 79-90
DOI 10.1037/per0000352, PubMed 31580097

Buer Christensen T, Hummelen B, Paap MCS, Eikenaes I, Selvik SG, Kvarstein E, Pedersen G, Bender DS, Skodol AE, Nysæter TE (2019)
Evaluation of Diagnostic Thresholds for Criterion A in the Alternative DSM-5 Model for Personality Disorders
J Pers Disord, 34 (Supplement C), 40-61
DOI 10.1521/pedi_2019_33_455, PubMed 31682197

Normann-Eide E, Antonsen BRT, Kvarstein EH, Pedersen G, Vaskinn A, Wilberg T (2019)
Are Impairments in Theory of Mind Specific to Borderline Personality Disorder?
J Pers Disord, 34 (6), 827-841
DOI 10.1521/pedi_2019_33_417, PubMed 30785865

Pedersen G, Arnevik EA, Hummelen B, Walderhaug E, Wilberg T (2019)
Psychometric Properties of the Severity Indices of Personality Problems (SIPP) in Two Samples A Norwegian Community Sample and Clinical Samples of Patients With and Without Personality Disorders
Eur. J. Psychol. Assess., 35 (5), 698-711
DOI 10.1027/1015-5759/a000436

Publications 2018

Buer Christensen T, Paap MCS, Arnesen M, Koritzinsky K, Nysaeter TE, Eikenaes I, Germans Selvik S, Walther K, Torgersen S, Bender DS, Skodol AE, Kvarstein E, Pedersen G, Hummelen B (2018)
Interrater Reliability of the Structured Clinical Interview for the DSM-5 Alternative Model of Personality Disorders Module i: Level of Personality Functioning Scale
J Pers Assess, 100 (6), 630-641
DOI 10.1080/00223891.2018.1483377, PubMed 30084661

Büchmann CB, Pedersen G, Aminoff SR, Laskemoen JF, Barrett EA, Melle I, Lagerberg TV (2018)
Validity of the Birchwood insight scale in patients with schizophrenia spectrum- and bipolar disorders
Psychiatry Res, 272, 715-722
DOI 10.1016/j.psychres.2018.12.072, PubMed 30832191

Kvarstein EH, Pedersen G, Folmo E, Urnes Ø, Johansen MS, Hummelen B, Wilberg T, Karterud S (2018)
Mentalization-based treatment or psychodynamic treatment programmes for patients with borderline personality disorder - the impact of clinical severity
Psychol Psychother, 92 (1), 91-111
DOI 10.1111/papt.12179, PubMed 29582581

Publications 2017

Paap MCS, Braeken J, Pedersen G, Urnes Ø, Karterud S, Wilberg T, Hummelen B (2017)
A Psychometric Evaluation of the DSM-IV Criteria for Antisocial Personality Disorder: Dimensionality, Local Reliability, and Differential Item Functioning Across Gender
Assessment, 27 (1), 89-101
DOI 10.1177/1073191117745126, PubMed 29284276

Publications 2016

Karterud S, Pedersen G, Johansen M, Wilberg T, Davis K, Panksepp J (2016)
Primary emotional traits in patients with personality disorders
Personal Ment Health, 10 (4), 261-273
DOI 10.1002/pmh.1345, PubMed 27257161

Lagerberg TV, Aminoff SR, Aas M, Bjella T, Henry C, Leboyer M, Pedersen G, Bellivier F, Icick R, Andreassen OA, Etain B, Melle I (2016)
Alcohol use disorders are associated with increased affective lability in bipolar disorder
J Affect Disord, 208, 316-324
DOI 10.1016/j.jad.2016.09.062, PubMed 27810713

Reas DL, Pedersen G, Rø Ø (2016)
Impulsivity-related traits distinguish women with co-occurring bulimia nervosa in a psychiatric sample
Int J Eat Disord, 49 (12), 1093-1096
DOI 10.1002/eat.22606, PubMed 27567004

Publications 2015

Eikenaes I, Pedersen G, Wilberg T (2015)
Attachment styles in patients with avoidant personality disorder compared with social phobia
Psychol Psychother, 89 (3), 245-60
DOI 10.1111/papt.12075, PubMed 26332087

Pedersen G, Eikenæs I, Urnes Ø, Skulberg GM, Wilberg T (2015)
Experiences in Close Relationships – Psychometric properties among patients with personality disorders
Personal Ment Health, 9 (3), 208-19
DOI 10.1002/pmh.1298, PubMed 26033784

Publications 2014

Antonsen BT, Klungsøyr O, Kamps A, Hummelen B, Johansen MS, Pedersen G, Urnes O, Kvarstein EH, Karterud S, Wilberg T (2014)
Step-down versus outpatient psychotherapeutic treatment for personality disorders: 6-year follow-up of the Ullevål personality project
BMC Psychiatry, 14, 119
DOI 10.1186/1471-244X-14-119, PubMed 24758722

Hummelen B, Pedersen G, Wilberg T, Karterud S (2014)
Poor Validity of the DSM-IV Schizoid Personality Disorder Construct as a Diagnostic Category
J Pers Disord, 29 (3), 334-46
DOI 10.1521/pedi_2014_28_159, PubMed 25248009

Kvarstein EH, Pedersen G, Urnes Ø, Hummelen B, Wilberg T, Karterud S (2014)
Changing from a traditional psychodynamic treatment programme to mentalization-based treatment for patients with borderline personality disorder--does it make a difference?
Psychol Psychother, 88 (1), 71-86
DOI 10.1111/papt.12036, PubMed 25045028

Nokleby H, Pedersen G, Skarderud F (2014)
Symptoms of Eating Disorders Among Females in Drug Addiction Treatment
J. Soc. Work Pract. Addict., 14 (3), 225-238
DOI 10.1080/1533256X.2014.933728

Pedersen G, Selsbakk JM, Theresa W, Sigmund K (2014)
Testing different versions of the Affective Neuroscience Personality Scales in a clinical sample
PLoS One, 9 (10), e109394
DOI 10.1371/journal.pone.0109394, PubMed 25289939

Pedersen G, Urnes Ø, Kvarstein EH, Karterud S (2014)
The three factors of the psychoticism scale of SCL-90-R
Personal Ment Health, 10 (3), 244-55
DOI 10.1002/pmh.1278, PubMed 25475425

Reas DL, Pedersen G, Karterud S, Rø Ø (2014)
Self-harm and suicidal behavior in borderline personality disorder with and without bulimia nervosa
J Consult Clin Psychol, 83 (3), 643-8
DOI 10.1037/ccp0000014, PubMed 25495360

Aas M, Pedersen G, Henry C, Bjella T, Bellivier F, Leboyer M, Kahn JP, Cohen RF, Gard S, Aminoff SR, Lagerberg TV, Andreassen OA, Melle I, Etain B (2014)
Psychometric properties of the Affective Lability Scale (54 and 18-item version) in patients with bipolar disorder, first-degree relatives, and healthy controls
J Affect Disord, 172, 375-80
DOI 10.1016/j.jad.2014.10.028, PubMed 25451440

Publications 2013

Reas DL, Rø Ø, Karterud S, Hummelen B, Pedersen G (2013)
Eating disorders in a large clinical sample of men and women with personality disorders
Int J Eat Disord, 46 (8), 801-9
DOI 10.1002/eat.22176, PubMed 23983043

Publications 2012

Karterud S, Pedersen G, Engen M, Johansen MS, Johansson PN, Schlüter C, Urnes O, Wilberg T, Bateman AW (2012)
The MBT Adherence and Competence Scale (MBT-ACS): development, structure and reliability
Psychother Res, 23 (6), 705-17
DOI 10.1080/10503307.2012.708795, PubMed 22916991

Paap MC, Meijer RR, Cohen-Kettenis PT, Richter-Appelt H, de Cuypere G, Kreukels BP, Pedersen G, Karterud S, Malt UF, Haraldsen IR (2012)
Why the factorial structure of the SCL-90-R is unstable: comparing patient groups with different levels of psychological distress using Mokken Scale Analysis
Psychiatry Res, 200 (2-3), 819-26
DOI 10.1016/j.psychres.2012.03.012, PubMed 22494703

Publications 2011

Hummelen B, Pedersen G, Karterud S (2011)
Some suggestions for the DSM-5 schizotypal personality disorder construct
Compr Psychiatry, 53 (4), 341-9
DOI 10.1016/j.comppsych.2011.05.009, PubMed 21741634

Pedersen G, Karterud S (2011)
The symptom and function dimensions of the Global Assessment of Functioning (GAF) scale
Compr Psychiatry, 53 (3), 292-8
DOI 10.1016/j.comppsych.2011.04.007, PubMed 21632038

Paap MC, Meijer RR, Van Bebber J, Pedersen G, Karterud S, Hellem FM, Haraldsen IR (2011)
A study of the dimensionality and measurement precision of the SCL-90-R using item response theory
Int J Methods Psychiatr Res, 20 (3), e39-55
DOI 10.1002/mpr.347, PubMed 21812065

Publications 2010

Karterud S, Øien M, Pedersen G (2010)
Validity aspects of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, narcissistic personality disorder construct
Compr Psychiatry, 52 (5), 517-26
DOI 10.1016/j.comppsych.2010.11.001, PubMed 21193181

Leirvåg H, Pedersen G, Karterud S (2010)
Long-term continuation treatment after short-term day treatment of female patients with severe personality disorders: Body awareness group therapy versus psychodynamic group therapy
Nord J Psychiatry, 64 (2), 115-22
DOI 10.3109/08039480903487525, PubMed 20392134

Pedersen G, Karterud S (2010)
Using measures from the SCL-90-R to screen for personality disorders
Personal. Ment. Health, 4 (2), 121-132
DOI 10.1002/pmh.122

Rossberg JI, Karterud S, Pedersen G, Friis S (2010)
Psychiatric symptoms and countertransference feelings: an empirical investigation
Psychiatry Res, 178 (1), 191-5
DOI 10.1016/j.psychres.2009.09.019, PubMed 20452056

Publications 2009

Falkum E, Pedersen G, Karterud S (2009)
Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, paranoid personality disorder diagnosis: a unitary or a two-dimensional construct?
Compr Psychiatry, 50 (6), 533-41
DOI 10.1016/j.comppsych.2009.01.003, PubMed 19840591

Wilberg T, Karterud S, Pedersen G, Urnes Ø (2009)
The impact of avoidant personality disorder on psychosocial impairment is substantial
Nord J Psychiatry, 63 (5), 390-6
DOI 10.1080/08039480902831322, PubMed 19333817

Wilberg T, Karterud S, Pedersen G, Urnes Ø, Costa PT (2009)
Nineteen-month stability of Revised NEO Personality Inventory domain and facet scores in patients with personality disorders
J Nerv Ment Dis, 197 (3), 187-95
DOI 10.1097/NMD.0b013e3181923fa0, PubMed 19282686

Publications 2008

Halsteinli V, Karterud S, Pedersen G (2008)
When costs count: the impact of staff size, skill mix and treatment intensity on patient outcome for psychotherapeutic day treatment programmes
Health Policy, 86 (2-3), 255-65
DOI 10.1016/j.healthpol.2007.10.013, PubMed 18083268

Hummelen B, Wilberg T, Pedersen G, Karterud S (2008)
The quality of the DSM-IV obsessive-compulsive personality disorder construct as a prototype category
J Nerv Ment Dis, 196 (6), 446-55
DOI 10.1097/NMD.0b013e3181775a4e, PubMed 18552621

Rossberg JI, Karterud S, Pedersen G, Friis S (2008)
Specific personality traits evoke different countertransference reactions: an empirical study
J Nerv Ment Dis, 196 (9), 702-8
DOI 10.1097/NMD.0b013e318186de80, PubMed 18791432

Wilberg T, Hummelen B, Pedersen G, Karterud S (2008)
A study of patients with personality disorder not otherwise specified
Compr Psychiatry, 49 (5), 460-8
DOI 10.1016/j.comppsych.2007.12.008, PubMed 18702931

Publications 2007

Pedersen G, Karterud S (2007)
Associations between patient characteristics and ratings of treatment milieu
Nord J Psychiatry, 61 (4), 271-8
DOI 10.1080/08039480701414999, PubMed 17763120

Rossberg JI, Karterud S, Pedersen G, Friis S (2007)
An empirical study of countertransference reactions toward patients with personality disorders
Compr Psychiatry, 48 (3), 225-30
DOI 10.1016/j.comppsych.2007.02.002, PubMed 17445515