https://orcid.org/0000-0002-3999-137X
Figures
Abstract
Introduction
An association between personality factors and pain experience has been investigated. However, the direct contributions of personality traits by the Maudsley Personality Inventory to clinical pain outcomes in patients with chronic pain remain unclear. The Maudsley Personality Inventory is a self-report questionnaire used to assess extroversion, neurotic tendencies, and lying or exhibitionistic tendencies. The present study aimed to investigate whether personality traits influenced with the pain-related psychological variables in patients with chronic secondary low back pain (CLBP).
Methods
One hundred fifteen consecutive outpatients with CLBP were included. Personality traits were measured by using the Maudsley Personality Inventory to assess extroversion, neurotic tendencies, and lying or exhibitionistic tendencies. The association of Maudsley neurotic tendency score and pain-related variables was analyzed and then performed a path analysis. Eleven patients (9%) were the biased persons with frequent lying.
Results
The pain-related variables showed no significant differences between the persons with frequent lying and those with normal. The Maudsley neurotic tendency score was significantly associated with Pain Catastrophizing Scale, Hospital Anxiety and Depression Scale, Pain Self-Efficacy Questionnaire, Athens Insomnia Scale, and EuroQol-5 Dimensions-3 level. The unstandardized coefficients for Maudsley neurotic tendency score were small, compared to pain-Numerical Rating Scale in each outcome.
Citation: Hayashi K, Miki K, Fukushima Y, Iwai M, Shiro Y, Tetsunaga T, et al. (2026) Personality traits have an effect on pain-related psychological variables in patients with chronic low back pain. PLoS One 21(7): e0354827. https://doi.org/10.1371/journal.pone.0354827
Editor: Omid Beiki, Karolinska Institutet, SWEDEN
Received: January 14, 2026; Accepted: July 13, 2026; Published: July 31, 2026
Copyright: © 2026 Hayashi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The minimal data set is available in the supplementary materials.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Introduction
The lifetime prevalence of low back pain has been reported to be as high as 84%, and estimates suggest that approximately 23% of individuals experience chronic low back pain, with 11–12% of the population being disabled by low back pain across diverse populations [1]. Chronic pain is defined as pain that persists or recurs for longer than 3 months [2]. Chronic pain interferes with daily functioning, and is often accompanied by emotional distress [2]. A bio-psycho-social model is recommended to inform assessment and management, given the associations between behavioral, psychological, and social factors and the future persistence of pain and disability [3]. Pain-related psychological disturbances are widely assessed using self-reported questionnaires [4].
Psychological disturbance is influenced by personality trait [5,6]. Personality traits are enduring patterns of perceiving, relating to, and thinking about oneself and the environment, and are exhibited across a wide range of social and personal contexts [7]. Neuroticism is strongly associated with psychological disturbance, whereas extraversion shows independent effect [5,6]. Since the 19th century, an association between personality factors and the pain experience has been investigated [8]. A recent review concluded that personality traits are associated with experimental pain in healthy individuals [9] and clinical pain outcomes in patients with musculoskeletal pain [10]. Neuroticism and extraversion are associated with health outcomes in patients with chronic pain in the Western countries [11–13], while not adequately investigated in non-Western country. Most studies assess personality traits using the Big-Five trait model, which includes extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience [9,10]. The inventory does not typically include items assessing lying or biased responding [5,6]. When individuals are asked to rate themselves across personality dimensions, they may exaggerate their positive qualities and downplay their negative qualities [14]. The big five are not discrete, independent dimensions but rather represent partially overlapping and increasingly complex groups of facets [15,16]. Another, most studies are reported in the Western countries, even though Asians scored higher on neuroticism, and lower on extraversion, conscientiousness, and openness [17].
Then, a tool for alternative personality traits, the Maudsley Personality Inventory, includes a scale comprising 20 items designed to test lying [18]. It is a self-report questionnaire used to assess extroversion, neurotic tendencies, and lying or exhibitionistic tendencies, and is associated with psychological functioning. The items of Maudsley were selected to minimize correlation between the neurotic tendency and extraversion scales [19]. Shiomi 1978 first suggested that the Maudsley neurotic tendency score (N-score) and extraversion score (E-score) are associated with experimental pain in healthy individuals [20]. Later, Kasai 2017 suggested that Maudsley lye score (L-score) is significantly higher among outpatients experiencing a high degree of pain [21]. Personality traits, as well as pain intensity, have been shown to influence pain-related psychological outcomes [22]. However, the direct contributions of personality traits by the Maudsley Personality Inventory to clinical pain outcomes in patients with chronic pain remain unclear.
The present study aimed to investigate whether personality traits influence pain-related psychological variables in patients with chronic secondary low back pain (CLBP).
Methods
Participants
Participants were recruited consecutively from outpatient clinic in Japan between 17/01/2025 and 19/12/2025. The patients were eligible if they (1) were older than 18 years of age, (2) were diagnosed with chronic secondary pain in low back due to trauma or surgery, and (3) had persistent low back pain for at least 6 months prior to enrollment in the study. Exclusion criteria were: (1) unwillingness to participate, (2) pain related to tumors or presence of neurological symptoms, (3) surgery within the previous 3 months, (4) use of medications associated with dementia, and (5) were poor Japanese language comprehension. All inclusion and exclusion criteria were assessed by the referring physicians.
This cross-sectional study was approved by the Ethics Committee of Hayaishi Hospital (R070110-01), and all study participants provided written informed consent. All experiments were registered (UMIN000056708; Registration, Jan 14, 2025). All methods were carried out in accordance with relevant guidelines and regulations, in accordance with the Declaration of Helsinki.
Measures
Demographic data, including age, sex, height, weight, body mass index, marital status, exercise habits, welfare recipient status, occupation, and education were collected during the participants’ first visit to the clinic. Personality traits were assessed using the Japanese version of the Maudsley Personality Inventory [19,23]. The Maudsley E-score can ranges from 0 to 48, with higher scores indicating greater extroversion (normal average, 21–31). The Maudsley N-score ranges from 0 to 48, with higher scores indicating greater neurotic tendencies (normal average, 19–28). The Maudsley L-score ranges from 0 to 40, with higher scores reflecting higher levels of lying or exhibitionistic tendencies (normal average, 0–25).
Pain related variables were assessed using the following questionnaires: the Pain-Numerical Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), Pain Disability Assessment Scale (PDAS), Pain Self-Efficacy Questionnaire (PSEQ), Athens Insomnia Scale, 25-question Geriatric Locomotive Function Scale (Locomo-25), and EuroQol-5 Dimensions-3 level (EQ-5D-3L). All questionnaires included translated versions in Japanese and were analyzed as continuous variables.
Pain intensity was measured using the 0 − 10 NRS [24]. The pain-NRS scale, ranging from 0 to 10, was used to indicate the average level of pain experienced during the day, with 0 representing “no pain” and 10 representing the “worst pain imaginable.”
The PCS score consists of 13 items, with participants indicating how frequently they experience each cognition or emotion [25,26]. The total PCS score ranges from 0 to 52, with higher scores reflecting greater levels of catastrophizing.
The HADS was designed to assess two separate dimensions of anxiety and depression [27,28]. The HADS score consists of 14 items, with the anxiety (HADS-Anxiety) and depression (HADS-Depression) subscales each containing 7 items. Responses are rated on a four-point scale, ranging from 0 (absence of symptoms) to 3 (maximum symptoms), resulting in possible subscale scores from 0 to 21.
The PDAS score assesses the extent to which chronic pain interferes with various daily activities over the past week [29]. The PDAS comprises 20 items covering a broad range of daily activities, with respondents indicating the degree of interference caused by pain. Total scores range from 0 to 60, with higher scores reflecting greater levels of pain interference.
The PSEQ score assesses the self-efficacy beliefs despite pain [30,31]. The PSEQ comprises 10 items reflecting pain self efficacy. It regards self-efficacy in physical functioning, social interactions and engagement in valued activities. Total scores range from 0 to 60, with lower scores indicating lower levels of self-efficacy.
The Athens Insomnia Scale score assesses the severity of insomnia symptoms [32,33]. Total scores range from 0 to 24, with higher scores indicating greater insomnia severity.
The Locomo-25 score assesses the declines in mobility functions due to locomotive organ impairment [34]. It evaluates impairments in the musculoskeletal system resulting in pain, limited range of motion, muscle weakness, or balance problems. Total scores range from 0 to 100, with higher scores indicating greater difficulties and disabilities in daily activities related to locomotive function.
The EQ-5D-3L scores assess subjective health-related quality of life (QOL) [35,36]. The instrument evaluates health across five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is assessed with a single question offering three possible responses: no problems, some problems, or serious health problems. EQ-5D-3L scores range from −0.111 to 1.000, with negative scores indicating health states considered worse than death, 0 representing death, and 1.000 representing full health.
Statistical analysis
All continuous data are expressed as means and standard deviations. The normality of continuous variables was evaluated using the Shapiro-Wilk test. Depending on the data distribution, groups classified according to the Maudsley E-, N-, or L-scores were compared using either unpaired t-tests or Mann-Whitney U tests. Categorical variables are represented as counts and percentage, and were analyzed using the χ2 test. Correlations among continuous variables were assessed using the Pearson correlation coefficient.
Path analysis was conducted to examine relationships among variables. Pain-related psychological variables that showed significant and moderate correlation with the Maudsley N-score (p-value, < 0.05; and correlation coefficient, > 0.3) were included as primary outcomes in the subsequent path analysis. The Maudsley N-score and pain-NRS were included as predictors. Unstandardized coefficient, standard errors, and 95% confidence interval were calculated. The unstandardized coefficient represented the expected change in the outcome variable for each one-unit increase in the predictor variable. Model fit was assessed using the goodness of fit index (GFI) > 0.95, adjusted goodness of fit index (AGFI) > 0.95, comparative fit index (CFI) > 0.95, Tucker-Lewis index (TLI) > 0.95, and root mean square error of approximation (RMSEA) ≤ 0.05 [37]. All analyses were performed using JMP Pro 17 (version 17.0.0, SAS Institute Inc., Cary, NC, USA). A p value of < 0.05 was considered statistically significant.
The sample size was calculated using the G*Power software (version 3.1.9.2; Franz Faul, Kiel University, Kiel, Germany). Based on an effect size of 0.26 [11–13] the minimum number of subjects was estimated to be 111 for an α-level of 0.05, and a power (1 – β) of 0.80. Because we expected that the data from persons with frequent lying could be outliers [38], 115 patients with CLBP were recruited.
Results
Patient characteristics are shown in Table 1. The mean age of the patients was 54.9 years. Of the 115 patients, 73 (63%) were women. The mean pain-NRS value was 5.5. Eleven patients (9%) were the biased persons with frequent lying (Maudsley L-score, > 25 points). The pain-related variables showed no significant differences between the persons with frequent lying and those with normal, except for PDAS score. The patients with the neurotic tendency (Maudsley N-score, > 28 points) consistently showed the introversion trait (Maudsley E-score, < 21 points) (S1A Table). The Maudsley subscores showed small or moderate correlations with each other (S1B Table).
Correlations between the Maudsley subscores and variables are shown in Table 2. The Maudsley N-score was significantly associated with Pain Catastrophizing Scale (r = 0.370), HADS Anxiety (r = 0.491), HADS Depression (r = 0.452), PSEQ (r = −0.283), Athens Insomnia Scale (r = 0.292), and EQ-5D-3L (r = −0.186). The Maudsley E-score was significantly associated with Pain Catastrophizing Scale (r = −0.218). The Maudsley L-score was significantly associated with age (r = 0.274). The correlations are similar in patients with frequent lying (Maudsley L-score, > 25 points; n = 11) (S2 Table) and those with normal (Maudsley L-score, ≤ 25 points; n = 104) (S3 Table). Thus, we used the data from all patients for the subsequent analysis (n = 115).
The patients with the neurotic tendency (Maudsley N-score, > 28 points) showed significantly higher Pain Catastrophizing Scale, HADS Anxiety, HADS Depression, and Athens Insomnia Scale, while lower PSEQ, and EQ-5D-3L, compared to patients with low neurotic tendency or average (Maudsley N-score, ≤ 28 points) (Table 3). Comparison of data between patients with introversion and those with extroversion (Maudsley E-score) showed no statistical differences (Table 4).
The path analysis included the outcomes with moderate correlation to improve the fitness of the model. Maudsley N-score and pain-NRS significantly influenced with Pain Catastrophizing Scale, HADS Anxiety, and HADS Depression in the path analysis. However, the unstandardized coefficients for Maudsley N-score was small (0.177–0.316), compared to pain-NRS (0.698–1.964) in each outcome. The fitness of the model was poor (GFI, 0.686; AGFI, 0.566; CFI, 0.468; TLI, 0.329; and RMSEA, 0.531) (Fig 1) (Table 5).
HADS, Hospital Anxiety and Depression Scale; Maudsley N-score, neurotic tendency score; NRS, Numerical Rating Scale. Maudsley N-score and pain-NRS significantly influenced with Pain Catastrophizing Scale, HADS Anxiety, and HADS Depression in the path analysis. However, the unstandardized coefficients for Maudsley N-score was small, compared to pain-NRS in each outcome. The fitness of the model was poor. *Significance level was set at < 5%.
Discussion
The present study demonstrated that patients with the neurotic tendency showed significantly higher levels of pain catastrophizing, anxiety, and depression, compared with patients with low or average levels of neurotic tendency among individuals with CLBP, with small effect sizes.
Neuroticism is the propensity to experience negative emotions, including anxiety, fear, sadness, anger, guilt, disgust, irritability, loneliness, worry, self-consciousness, dissatisfaction, hostility, embarrassment, reduced self-confidence, and feelings of vulnerability, in response to various types of stress [5]. Negative life experiences, whether in aggregate or in particular, are generally associated with increases in neuroticism [39]. Neuroticism is assessed using a variety of standardized questionnaire instruments [5]. There is a common tendency to equate personality among patients [16]. Although personality traits are not all-encompassing, nor do they adequately capture the units of analysis typically included under the broad umbrella of personality psychology [16]. Neuroticism is correlated with brain activity in regions involved in emotional and cognitive pain processing, including the para-hippocampus, insula, thalamus, and anterior cingulate cortex [40]. Whole-brain resting-state functional neuroimaging studies suggested neuroticism is positively correlated with the brain activity in the left middle temporal gyrus, left striatum, and right hippocampus, and negatively correlated in the left superior temporal gyrus, and right supramarginal gyrus [41]. Several potential mechanisms have been proposed to explain the relationship between neuroticism and chronic pain through heightened physical sensitivity, pain-related beliefs, emotional distress, less-adaptive, or passive coping strategies, however, these mechanisms are complex and remain uncertain [8]. Personality vulnerabilities may lead certain individuals to be more threatened by pain, thereby resulting in greater pain-related fear, avoidance and disability [42]. Meanwhile, evidences whether neuroticism is associated with a greater pain-related psychological disturbance [43], or not [44] are contradictory. The present study suggested that neuroticism has a statistically significant, but small, effect on pain-related psychological variables.
Neuroticism and other personality traits were found to be modifiable through both clinical and nonclinical interventions [45]. Among personality domains, neuroticism and extraversion show the greatest chance of change [45]. Numerous studies reported the effects of cognitive behavior therapy, psychodynamic approaches, and nonclinical intervention, however, the type of therapy employed is not strongly associated with the magnitude of change in personality traits [45]. Examination of the relationship between treatment duration and personality change showed that most gains occur within the first month of therapy [45]. A variety of efforts at improving cognitive functioning could change personality traits more rapidly than commonly thought [45]. Personality traits could be useful in guiding clinical decision making for rehabilitation [10]. That is, high levels of neuroticism could be associated with worse prognosis and low adherence with a rehabilitation program [10]. The patient may benefit from more frequent in-clinic visits and additional psychological intervention.
A previous study reported the characteristics and pain in the individuals with high Maudsley L-score [21]. Participants were recruited regardless of disease or pain, and three quarter reported no pain or only mild pain [21]. Based on these results, they suggested that the Maudsley L-score is not strongly influenced by an individual’s state of mind or situation [21]. The Maudsley L-score was significantly higher among individuals with a high degree of pain [21]. Similarly, the present study suggested Maudsley L-score showed no concordant relationship with any pain-related variables. The present study included patients with CLBP from outpatient clinic, who reported an average of 5.5 on a 0–10 point pain-NRS. In both studies, fewer than 10% of participants exhibited a high Maudsley L-score. The Maudsley Personality Inventory easily measures personality, comparable to the Minnesota Multiphasic Personality Inventory, and includes a lie scale. PDAS scores were higher in patients with high Maudsley L-scores, although this interpretation should be made with caution due to the small sample size.
Chronic postsurgical or posttraumatic pain is defined that develops or increases in intensity following a surgical procedure or tissue injury and persists beyond the normal healing process [46,47]. Patients with chronic secondary pain indicated a higher diagnostic fit for new diagnoses compared with those with chronic primary pain [48]. Stigma experienced by individuals with chronic pain affects multiple aspects of daily life [49]. Distinguish between primary nonspecific or secondary pain would result in an accurate statistical representation, and lead to the development of effective treatments for patients [46,47].
There are several limitations to the present study. First, personality traits were measured using self-reported questionnaire. Most tools for personality traits are concerned about potential oversimplification and response biases [45]. Second, the present study used a cross-sectional design conducted in a single country across a couple of medical centers. Our observations must therefore be interpreted with caution.
Conclusions
The patients with the neurotic tendency showed significantly higher pain catastrophizing, anxiety, and depression, compared to patients with low neurotic tendency or average. The Maudsley N-score influenced with pain-related psychological variables in CLBP, but the impact was small.
Supporting information
S1 Table. A) Comparison among Maudsley subscores.
B) Correlation between Maudsley subscores. Maudsley E-score, introversion/extroversion score; Maudsley L-score, lying tendencies score; Maudsley N-score, neurotic tendency score. Data from continuous variables are shown as mean (standard deviation). Data from categorical variables are shown as number (%). Significance level was set at < 5%. *, among groups by ANOVA test. †, versus low group by Tukey’s test. ‡, versus average group by Tukey’s test.
https://doi.org/10.1371/journal.pone.0354827.s001
(DOCX)
S2 Table. Correlation between Maudsley subscore and the variables in patients with Frequent lying in Maudsley L-score (n = 11).
EQ-5D-3L, Euro Quality of life-5 Dimensions-3 level; HADS, Hospital Anxiety and Depression Scale; Locomo-25, the 25-question Geriatric Locomotive Function Scale; Maudsley E-score, introversion/extroversion score; Maudsley L-score, lying tendencies score; Maudsley N-score, neurotic tendency score; NRS, Numerical Rating Scale; PDAS, Pain Disability Assessment Scale; PSEQ, Pain Self-Efficacy Questionnaire. * Significance level was set at < 5% by the Pearson correlation coefficient test.
https://doi.org/10.1371/journal.pone.0354827.s002
(DOCX)
S3 Table. Correlation between Maudsley subscore and the variables in patients with normal score in Maudsley L-score (n = 104).
EQ-5D-3L, Euro Quality of life-5 Dimensions-3 level; HADS, Hospital Anxiety and Depression Scale; Locomo-25, the 25-question Geriatric Locomotive Function Scale; Maudsley E-score, introversion/extroversion score; Maudsley L-score, lying tendencies score; Maudsley N-score, neurotic tendency score; NRS, Numerical Rating Scale; PDAS, Pain Disability Assessment Scale; PSEQ, Pain Self-Efficacy Questionnaire. * Significance level was set at < 5% by the Pearson correlation coefficient test.
https://doi.org/10.1371/journal.pone.0354827.s003
(DOCX)
Acknowledgments
The authors thank Yukioka Hospital and Hayaishi Hospital for their cooperation. The authors sincerely thank all patients, collaborating physicians, and other medical staff for their important contributions to this study.
References
- 1. Balagué F, Mannion AF, Pellisé F, Cedraschi C. Non-specific low back pain. Lancet. 2012;379(9814):482–91. pmid:21982256
- 2. Treede R-D, Rief W, Barke A, Aziz Q, Bennett MI, Benoliel R, et al. Chronic pain as a symptom or a disease: the IASP Classification of Chronic Pain for the International Classification of Diseases (ICD-11). Pain. 2019;160(1):19–27. pmid:30586067
- 3. Foster NE, Anema JR, Cherkin D, Chou R, Cohen SP, Gross DP, et al. Prevention and treatment of low back pain: evidence, challenges, and promising directions. Lancet. 2018;391(10137):2368–83. pmid:29573872
- 4. Turk DC, Fillingim RB, Ohrbach R, Patel KV. Assessment of Psychosocial and Functional Impact of Chronic Pain. J Pain. 2016;17(9 Suppl):T21-49. pmid:27586830
- 5. Jeronimus BF, Kotov R, Riese H, Ormel J. Neuroticism’s prospective association with mental disorders halves after adjustment for baseline symptoms and psychiatric history, but the adjusted association hardly decays with time: a meta-analysis on 59 longitudinal/prospective studies with 443 313 participants. Psychol Med. 2016;46(14):2883–906. pmid:27523506
- 6. Kotov R, Gamez W, Schmidt F, Watson D. Linking “big” personality traits to anxiety, depressive, and substance use disorders: a meta-analysis. Psychol Bull. 2010;136(5):768–821. pmid:20804236
- 7.
American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-IV. 4th ed. American Psychiatric Association. 1994.
- 8. Naylor B, Boag S, Gustin SM. New evidence for a pain personality? A critical review of the last 120 years of pain and personality. Scand J Pain. 2017;17:58–67. pmid:28850375
- 9. Atanassova DV, Madariaga VI, Oosterman JM, Brazil IA. Unpacking the relationship between Big Five personality traits and experimental pain: A systematic review and meta-analysis. Neurosci Biobehav Rev. 2024;163:105786. pmid:38955000
- 10. Williams MK, Waite L, Van Wyngaarden JJ, Meyer AR, Koppenhaver SL. Beyond yellow flags: The Big-Five personality traits and psychologically informed musculoskeletal rehabilitation. Musculoskeletal Care. 2023;21(4):1161–74. pmid:37434350
- 11. Cojocaru C-M, Popa CO, Schenk A, Marian Ștefan, Marchean H, Suciu BA, et al. Personality and Pain Outcomes in Rheumatic Disease: The Mediating Role of Psychological Flexibility. Healthcare (Basel). 2024;12(11):1087. pmid:38891162
- 12. Ibrahim ME, Weber K, Courvoisier DS, Genevay S. Big Five Personality Traits and Disabling Chronic Low Back Pain: Association with Fear-Avoidance, Anxious and Depressive Moods. J Pain Res. 2020;13:745–54.
- 13. Talaei-Khoei M, Mohamadi A, Fischerauer SF, Ring D, Vranceanu A-M. Type D personality in patients with upper extremity musculoskeletal illness: Internal consistency, structural validity and relationship to pain interference. Gen Hosp Psychiatry. 2018;50:38–44. pmid:28992609
- 14.
Paulhus DL. Socially desirable responding: The evolution of a construct. In: Braun HI, Jackson DN, editors. The role of constructs in psychological and educational measurement. Lawrence Erlbaum Associates Publishers. 2002. p. 37–48.
- 15. Condon DM, Mroczek DK. Time to Move Beyond the Big Five?. Eur J Pers. 2016;30(4):311–2. pmid:29491551
- 16. Roberts BW, Yoon HJ. Personality psychology. Annu Rev Psychol. 2022;73:489–516.
- 17. Eap S, Degarmo DS, Kawakami A, Hara SN, Hall GCN, Teten AL. Culture and Personality Among European American and Asian American Men. J Cross Cult Psychol. 2008;39(5):630–43. pmid:19169434
- 18. Gibson HB. The lie scale of the Maudsley personality inventory. Acta Psychologica. 1962;20:18–23.
- 19. Jensen AR. The Maudsley personality inventory. Acta Psychologica. 1958;14:314–25.
- 20. Shiomi K. Relations of pain threshold and pain tolerance in cold water with scores on Maudsley Personality Inventory and Manifest Anxiety Scale. Percept Mot Skills. 1978;47(3 Pt 2):1155–8. pmid:745891
- 21. Kasai Y, Sakakibara T, Mizuno T. Characteristics of Patients with High Lie Scores in a Personality Test. Indian J Psychol Med. 2017;39(4):418–21. pmid:28852232
- 22. Martínez MP, Sánchez AI, Miró E, Medina A, Lami MJ. The relationship between the fear-avoidance model of pain and personality traits in fibromyalgia patients. J Clin Psychol Med Settings. 2011;18(4):380–91. pmid:21964824
- 23.
Ooyama T, Komatsu R. Preparation and validation of Japanese Maudsley personality inventory. In: Japanese MPI study group, editor. New personality inventory-Maudsley personality inventory. 1st ed. Seishinsho. 1969. p. 115–57.
- 24. Gewandter JS, Dworkin RH, Turk DC, Farrar JT, Fillingim RB, Gilron I, et al. Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations. Pain. 2015;156(7):1184–97. pmid:25887465
- 25. Sullivan MJL, Bishop SR, Pivik J. The Pain Catastrophizing Scale: Development and validation. Psychological Assessment. 1995;7:524–32.
- 26. Matsuoka H, Sakano Y. Assessment of cognitive aspect of pain: development, reliability, and validation of Japanese version of Pain Catastrophizing Scale. Jpn J Psychosom Med. 2007;47:95–102.
- 27. Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983;67(6):361–70. pmid:6880820
- 28. Kugaya A, Akechi T, Okuyama T, Okamura H, Uchitomi Y. Screening for psychological distress in Japanese cancer patients. Jpn J Clin Oncol. 1998;28(5):333–8. pmid:9703862
- 29. Yamashiro K, Arimura T, Iwaki R, Jensen MP, Kubo C, Hosoi M. A multidimensional measure of pain interference: reliability and validity of the pain disability assessment scale. Clin J Pain. 2011;27(4):338–43. pmid:21178590
- 30. Nicholas MK. The pain self-efficacy questionnaire: Taking pain into account. Eur J Pain. 2007;11(2):153–63. pmid:16446108
- 31. Adachi T, Nakae A, Maruo T, Shi K, Shibata M, Maeda L, et al. Validation of the Japanese version of the pain self-efficacy questionnaire in Japanese patients with chronic pain. Pain Med. 2014;15(8):1405–17. pmid:24717053
- 32. Soldatos CR, Dikeos DG, Paparrigopoulos TJ. Athens Insomnia Scale: validation of an instrument based on ICD-10 criteria. J Psychosom Res. 2000;48:555–60.
- 33. Okajima I, Nakajima S, Kobayashi M, Inoue Y. Development and validation of the Japanese version of the Athens Insomnia Scale. Psychiatry Clin Neurosci. 2013;67(6):420–5. pmid:23910517
- 34. Seichi A, Hoshino Y, Doi T, Akai M, Tobimatsu Y, Iwaya T. Development of a screening tool for risk of locomotive syndrome in the elderly: the 25-question Geriatric Locomotive Function Scale. J Orthop Sci. 2012;17(2):163–72. pmid:22222445
- 35. EuroQol Group. EuroQol--a new facility for the measurement of health-related quality of life. Health Policy. 1990;16(3):199–208. pmid:10109801
- 36. Tsuchiya A, Ikeda S, Ikegami N. Estimating an EQ-5D population value set: the case of Japan. Health Econ. 2002;11:341–53.
- 37. Babyak MA, Green SB. Confirmatory factor analysis: an introduction for psychosomatic medicine researchers. Psychosom Med. 2010;72(6):587–97. pmid:20467001
- 38. Wang Z, Sakakibara T, Kasai Y. Personality of outpatients with malignant tumors: a cross-sectional study. World J Surg Oncol. 2012;10:187. pmid:22967001
- 39. Lüdtke O, Roberts BW, Trautwein U, Nagy G. A random walk down university avenue: life paths, life events, and personality trait change at the transition to university life. J Pers Soc Psychol. 2011;101(3):620–37. pmid:21744977
- 40. Coen SJ, Kano M, Farmer AD, Kumari V, Giampietro V, Brammer M, et al. Neuroticism influences brain activity during the experience of visceral pain. Gastroenterology. 2011;141(3):909-917.e1. pmid:21699797
- 41. Lin J, Li L, Pan N, Liu X, Zhang X, Suo X, et al. Neural correlates of neuroticism: A coordinate-based meta-analysis of resting-state functional brain imaging studies. Neurosci Biobehav Rev. 2023;146:105055. pmid:36681370
- 42. Vlaeyen JWS, Linton SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain. 2000;85(3):317–32. pmid:10781906
- 43. Wong WS, Lam HMJ, Chen PP, Chow YF, Wong S, Lim HS, et al. The fear-avoidance model of chronic pain: assessing the role of neuroticism and negative affect in pain catastrophizing using structural equation modeling. Int J Behav Med. 2015;22(1):118–31. pmid:24788315
- 44. Asghari A, Nicholas MK. Personality and pain-related beliefs/coping strategies: a prospective study. Clin J Pain. 2006;22(1):10–8. pmid:16340588
- 45. Roberts BW, Luo J, Briley DA, Chow PI, Su R, Hill PL. A systematic review of personality trait change through intervention. Psychol Bull. 2017;143(2):117–41. pmid:28054797
- 46. Treede R-D, Rief W, Barke A, Aziz Q, Bennett MI, Benoliel R, et al. A classification of chronic pain for ICD-11. Pain. 2015;156(6):1003–7. pmid:25844555
- 47. Schug SA, Lavand’homme P, Barke A, Korwisi B, Rief W, Treede RD. The IASP classification of chronic pain for ICD-11: chronic postsurgical or posttraumatic pain. Pain. 2019;160:45–52.
- 48. Korwisi B, Hay G, Forget P, Ryan D, Treede R-D, Rief W, et al. Patients’ perspective on the chronic pain classification in the 11th revision of the International Classification of Diseases (ICD-11): results from an international web-based survey. Pain. 2024;165(10):2356–63. pmid:38709273
- 49. Perugino F, De Angelis V, Pompili M, Martelletti P. Stigma and chronic pain. Pain Ther. 2022;11:1085–94.