{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T01:58:41Z","timestamp":1784858321578,"version":"3.55.0"},"reference-count":45,"publisher":"PeerJ","license":[{"start":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T00:00:00Z","timestamp":1771459200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian Ministry of University and Research"},{"name":"Research Project of National Interest"},{"name":"SCOPERTA","award":["2022BNMZJC"],"award-info":[{"award-number":["2022BNMZJC"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Parkinson\u2019s disease (PD) is a progressive neurodegenerative disorder primarily characterized by motor and cognitive symptoms. However, emerging evidence suggests that personality alterations may also be present, potentially affecting patients\u2019 quality of life and clinical outcomes. Prior studies have identified patterns such as lower openness and extraversion and higher neuroticism in PD patients, although findings have been inconsistent. This study aimed to investigate the structural organization of personality in PD using a network-based approach, and to examine the influence of age, sex, disease duration, and impulsive-compulsive symptoms on personality traits.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      A total of 237 PD patients (aged 45\u201386) completed the HEXACO Adjective Scale (HAS), assessing six personality traits: Honesty-Humility (H), Emotionality (E), Extraversion (X), Agreeableness (A), Conscientiousness (C), and Openness (O). Impulsive-compulsive behaviors were assessed using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson\u2019s Disease\u2013Rating Scale (QUIP-RS). Personality structure was analyzed\n                      <jats:italic>via<\/jats:italic>\n                      Exploratory Graph Analysis (EGA), a network model that identifies item clusters based on conditional dependencies. Multivariate multiple linear regression was used to test the effects of demographic and clinical variables on trait expression.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      EGA identified seven item-level communities. Traits E, X, and C formed coherent and distinct clusters, while items from A and H tended to cluster based on item polarity (positive\n                      <jats:italic>vs.<\/jats:italic>\n                      negative wording) rather than theoretical trait boundaries. O items split into two distinct communities, one composed of the items from the\n                      <jats:italic>Unconventionality<\/jats:italic>\n                      facet, and the other encompassing the remaining O items. At the trait level, HEXACO dimensions grouped into two higher-order clusters: a Cooperativity\u2013Integrity community (H, A, C) and an Engagement community (E, X, O). Regression analyses showed that higher ICD symptoms predicted lower levels of H, A, and C; longer disease duration was associated with lower C, and sex showed significant differences in\u00a0E.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>These findings reveal subtle but systematic alterations in the structural organization of personality traits in PD. Specifically, we observed a polarity-based overlap between H and A, possibly reflecting age-related convergence of the two traits\u2014consistent with a recent study reporting similar effects in healthy aging\u2014and a bifurcation within O centered on the Unconventionality facet, a trait often considered idiopathic in PD, even in its prodromal stages. These personality signatures may contribute to a refined clinical profiling of PD patients and support the value of incorporating personality assessment into personalized care approaches.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.7717\/peerj.20725","type":"journal-article","created":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T08:17:59Z","timestamp":1771489079000},"page":"e20725","source":"Crossref","is-referenced-by-count":1,"title":["The structure of personality in Parkinson\u2019s disease and the effects of age, years since diagnosis, and impulsivity"],"prefix":"10.7717","volume":"14","author":[{"given":"Stefano","family":"Vicentin","sequence":"first","affiliation":[{"name":"Institute for Psychology, Clinical Psychology and Psychotherapy in Childhood and Adolescence, Universit\u00e4t Osnabr\u00fcck, Osnabr\u00fcck, Lower Saxony, Germany"},{"name":"Department of General Psychology, University of Padua, Padua, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lavinia","family":"Chiriatti","sequence":"additional","affiliation":[{"name":"Department of General Psychology, University of Padua, Padua, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giorgia","family":"Cona","sequence":"additional","affiliation":[{"name":"Department of General Psychology, University of Padua, Padua, Italy"},{"name":"Padua Neuroscience Center, University of Padua, Padua, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"4443","published-online":{"date-parts":[[2026,2,19]]},"reference":[{"issue":"2","key":"10.7717\/peerj.20725\/ref-1","doi-asserted-by":"publisher","first-page":"150","DOI":"10.1177\/1088868306294907","article-title":"Empirical, theoretical, and practical advantages of the HEXACO model of personality structure","volume":"11","author":"Ashton","year":"2007","journal-title":"Personality and Social Psychology Review"},{"issue":"4","key":"10.7717\/peerj.20725\/ref-2","doi-asserted-by":"publisher","first-page":"340","DOI":"10.1080\/00223890902935878","article-title":"The HEXACO-60: a short measure of the major dimensions of personality","volume":"91","author":"Ashton","year":"2009","journal-title":"Journal of Personality Assessment"},{"issue":"7","key":"10.7717\/peerj.20725\/ref-3","doi-asserted-by":"publisher","first-page":"e675","DOI":"10.1212\/WNL.0000000000007942","article-title":"Impulse control disorders in Parkinson disease and RBD: a longitudinal study of severity","volume":"93","author":"Baig","year":"2019","journal-title":"Neurology"},{"key":"10.7717\/peerj.20725\/ref-4","doi-asserted-by":"publisher","first-page":"72","DOI":"10.1212\/WNL.0000000000007942","article-title":"Personality and addictive behaviours in early Parkinson\u2019s disease and REM sleep behaviour disorder","volume":"37","author":"Baig","year":"2017","journal-title":"Parkinsonism & Related Disorders"},{"issue":"1","key":"10.7717\/peerj.20725\/ref-5","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1016\/j.parkreldis.2013.09.006","article-title":"Impulsive and compulsive behaviors among Danish patients with Parkinson\u2019s disease: prevalence, depression, and personality","volume":"20","author":"Callesen","year":"2014","journal-title":"Parkinsonism & Related Disorders"},{"issue":"3","key":"10.7717\/peerj.20725\/ref-6","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1037\/0003-066X.54.3.165","article-title":"Taking time seriously: a theory of socioemotional selectivity","volume":"54","author":"Carstensen","year":"1999","journal-title":"American Psychologist"},{"issue":"6","key":"10.7717\/peerj.20725\/ref-7","doi-asserted-by":"publisher","first-page":"573","DOI":"10.1001\/archpsyc.1987.01800180093014","article-title":"A systematic method for clinical description and classification of personality variants. 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