Journal of clinical neurology

Korean Neurological Association (대한신경과학회)
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Validation of a Korean Version of the Insomnia Severity Index

  • Cho, Yong Won (Department of Neurology, Keimyung University Dongsan Medical Center) ;
  • Song, Mei Ling (Department of Graduate School in Nursing Science, College of Nursing, Keimyung University) ;
  • Morin, Charles M. (Ecole de Psychologie, Universite Laval)
  • Received : 2013.09.23
  • Accepted : 2014.01.10
  • Published : 2014.07.01
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Abstract

Background and Purpose The purposes of this study were to standardize and validate a Korean version of the Insomnia Severity Index (ISI-K), and to evaluate its clinical usefulness. Methods We translated the ISI into Korean and then translated it back into English to check its accuracy. The 614 patients with sleep disorders who were enrolled in this study comprised 169 with primary insomnia, 133 with comorbid insomnia, and 312 with obstructive sleep apnea. All subjects underwent one night of polysomnography (PSG) and completed the Korean versions of both the Pittsburgh Sleep Quality Index (PSQI-K) and the Epworth Sleepiness Scale, as well as the ISI-K. The ISI-K was compared to these sleep scales and various PSG sleep parameters. Results The internal consistency the ISI-K total score was confirmed by a Cronbach's alpha of 0.92, and the item-to-total-score correlations (item-total correlations) ranged from 0.65 to 0.84, suggesting adequate reliability. The correlation between the ISI-K total score and PSQI-K was 0.84, which suggested adequate convergent validity. Low-to-moderate correlations were obtained between the ISI-K total score and PSG-defined sleep parameters: 0.22 for sleep onset latency, 0.38 for wake after sleep onset, and 0.46 for sleep efficiency. A cutoff score of 15.5 on the ISI-K was optimal for discriminating patients with insomnia. The test-retest scores over a 4-week interval with 34 subjects yielded a correlation coefficient of 0.86, suggesting excellent temporal stability. Conclusions The findings of this study show that the ISI-K is a reliable and valid instrument for assessing the severity of insomnia in a Korean population.

Keywords

References

  1. Morphy H, Dunn KM, Lewis M, Boardman HF, Croft PR. Epidemiology of insomnia: a longitudinal study in a UK population. Sleep 2007;30:274-280.
  2. Ohayon MM. Epidemiology of insomnia: what we know and what we still need to learn. Sleep Med Rev 2002;6:97-111. https://doi.org/10.1053/smrv.2002.0186
  3. Zailinawati A, Ariff K, Nurjahan M, Teng C. Epidemiology of insomnia in Malaysian adults: a community-based survey in 4 urban areas. Asia Pac J Public Health 2008;20:224-233. https://doi.org/10.1177/1010539508316975
  4. Cho YW, Shin WC, Yun CH, Hong SB, Kim J, Earley CJ. Epidemiology of insomnia in Korean adults: prevalence and associated factors. J Clin Neurol 2009;5:20-23. https://doi.org/10.3988/jcn.2009.5.1.20
  5. Fortier-Brochu E, Beaulieu-Bonneau S, Ivers H, Morin CM. Insomnia and daytime cognitive performance: a meta-analysis. Sleep Med Rev 2012;16:83-94. https://doi.org/10.1016/j.smrv.2011.03.008
  6. Laraqui S, Hossini OL, Tripodi D, Manar N, Aoudi YE, Caubet A, et al. [Prevalence and risk factors of attention disorders of professional drivers in Morocco]. Sante Publique 2011;23:89-100. https://doi.org/10.3917/spub.112.0089
  7. Fernandez-Mendoza J, Calhoun S, Bixler EO, Pejovic S, Karataraki M, Liao D, et al. Insomnia with objective short sleep duration is associated with deficits in neuropsychological performance: a general population study. Sleep 2010;33:459-465. https://doi.org/10.1093/sleep/33.4.459
  8. Chen YY, Wu KC. Sleep habits and excessive daytime sleepiness correlate with injury risks in the general population in Taiwan. Inj Prev 2010;16:172-177. https://doi.org/10.1136/ip.2009.021840
  9. Mahgoub N, Majdak P, Friedman DB, Klimstra S. Insomnia and risk of falling in older adults. J Neuropsychiatry Clin Neurosci 2012;24:E5-E6.
  10. Morin CM, Benca R. Chronic insomnia. Lancet 2012;379:1129-1141. https://doi.org/10.1016/S0140-6736(11)60750-2
  11. Osorio RS, Pirraglia E, Aguera-Ortiz LF, During EH, Sacks H, Ayappa I, et al. Greater risk of Alzheimer's disease in older adults with insomnia. J Am Geriatr Soc 2011;59:559-562. https://doi.org/10.1111/j.1532-5415.2010.03288.x
  12. Sofi F, Cesari F, Casini A, Macchi C, Abbate R, Gensini GF. Insomnia and risk of cardiovascular disease: a meta-analysis. Eur J Prev Cardiol 2014;21:57-64. https://doi.org/10.1177/2047487312460020
  13. Haack M, Scott-Sutherland J, Santangelo G, Simpson NS, Sethna N, Mullington JM. Pain sensitivity and modulation in primary insomnia. Eur J Pain 2012;16:522-533. https://doi.org/10.1016/j.ejpain.2011.07.007
  14. Sohn SI, Kim do H, Lee MY, Cho YW. The reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index. Sleep Breath 2012;16:803-812. https://doi.org/10.1007/s11325-011-0579-9
  15. Cho YW, Lee JH, Son HK, Lee SH, Shin C, Johns MW. The reliability and validity of the Korean version of the Epworth sleepiness scale. Sleep Breath 2011;15:377-384. https://doi.org/10.1007/s11325-010-0343-6
  16. Bastien CH, Vallieres A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med 2001;2:297-307. https://doi.org/10.1016/S1389-9457(00)00065-4
  17. Chung KF, Kan KK, Yeung WF. Assessing insomnia in adolescents: comparison of Insomnia Severity Index, Athens Insomnia Scale and Sleep Quality Index. Sleep Med 2011;12:463-470. https://doi.org/10.1016/j.sleep.2010.09.019
  18. Sierra JC, Guillen-Serrano V, Santos-Iglesias P. [Insomnia Severity Index: some indicators about its reliability and validity on an older adults sample]. Rev Neurol 2008;47:566-570.
  19. Morin CM. Insomnia: Psychological Assessment and Management. New York: Guilford Press, 1993.
  20. Morin CM, Belleville G, Belanger L, Ivers H. The Insomnia Severity Index: psychometric indicators to detect insomnia cases and evaluate treatment response. Sleep 2011;34:601-608. https://doi.org/10.1093/sleep/34.5.601
  21. Savard MH, Savard J, Simard S, Ivers H. Empirical validation of the Insomnia Severity Index in cancer patients. Psychooncology 2005;14: 429-441. https://doi.org/10.1002/pon.860
  22. Omachi TA. Measures of sleep in rheumatologic diseases: Epworth Sleepiness Scale (ESS), Functional Outcome of Sleep Questionnaire (FOSQ), Insomnia Severity Index (ISI), and Pittsburgh Sleep Quality Index (PSQI). Arthritis Care Res (Hoboken) 2011;63 Suppl 11:S287-S296. https://doi.org/10.1002/acr.20544
  23. Tang NK, Wright KJ, Salkovskis PM. Prevalence and correlates of clinical insomnia co-occurring with chronic back pain. J Sleep Res 2007;16:85-95. https://doi.org/10.1111/j.1365-2869.2007.00571.x
  24. Yu DS. Insomnia Severity Index: psychometric properties with Chinese community-dwelling older people. J Adv Nurs 2010;66:2350-2359. https://doi.org/10.1111/j.1365-2648.2010.05394.x
  25. Lahan V, Gupta R. Translation and validation of the insomnia severity index in hindi language. Indian J Psychol Med 2011;33:172-176. https://doi.org/10.4103/0253-7176.92060
  26. Fernandez-Mendoza J, Rodriguez-Munoz A, Vela-Bueno A, Olavarrieta-Bernardino S, Calhoun SL, Bixler EO, et al. The Spanish version of the Insomnia Severity Index: a confirmatory factor analysis. Sleep Med 2012;13:207-210. https://doi.org/10.1016/j.sleep.2011.06.019
  27. Suleiman KH, Yates BC. Translating the insomnia severity index into Arabic. J Nurs Scholarsh 2011;43:49-53. https://doi.org/10.1111/j.1547-5069.2010.01374.x
  28. Morin CM, Vallieres A, Guay B, Ivers H, Savard J, Merette C, et al. Cognitive behavioral therapy, singly and combined with medication, for persistent insomnia: a randomized controlled trial. JAMA 2009; 301:2005-2015. https://doi.org/10.1001/jama.2009.682
  29. First MB, Frances A, Pincus HA. DSM-IV-TR Handbook of Differential Diagnosis. Washington, DC: American Psychiatric Press, 2002.
  30. American Academy of Sleep Medicine. The International Classification of Sleep Disorders: Diagnostic & Coding Manual. 2nd ed. Westchester: American Academy of Sleep Medicine, 2005.
  31. Sung HM, Kim JB, Park YN, Bai DS, Lee SH, Ahn HN. A study on the reliability and the validity of Korean version of the Beck Depression Inventory-II(BDI -II). J Korean Soc Biol Psychiatry 2008;14:201-212.
  32. Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res 1989;28:193-213. https://doi.org/10.1016/0165-1781(89)90047-4
  33. Littner M, Hirshkowitz M, Kramer M, Kapen S, Anderson WM, Bailey D, et al. Practice parameters for using polysomnography to evaluate insomnia: an update. Sleep 2003;26:754-760. https://doi.org/10.1093/sleep/26.6.754
  34. Reite M, Buysse D, Reynolds C, Mendelson W. The use of polysomnography in the evaluation of insomnia. Sleep 1995;18:58-70. https://doi.org/10.1093/sleep/18.1.58
  35. Akobeng AK. Understanding diagnostic tests 3: Receiver operating characteristic curves. Acta Paediatr 2007;96:644-647. https://doi.org/10.1111/j.1651-2227.2006.00178.x
  36. Perkins NJ, Schisterman EF. The inconsistency of "optimal" cutpoints obtained using two criteria based on the receiver operating characteristic curve. Am J Epidemiol 2006;163:670-675. https://doi.org/10.1093/aje/kwj063
  37. Zweig MH, Campbell G. Receiver-operating characteristic (ROC) plots: a fundamental evaluation tool in clinical medicine. Clin Chem 1993;39:561-577.
  38. Fischer JE, Bachmann LM, Jaeschke R. A readers' guide to the interpretation of diagnostic test properties: clinical example of sepsis. Intensive Care Med 2003;29:1043-1051. https://doi.org/10.1007/s00134-003-1761-8
  39. Swets JA. Measuring the accuracy of diagnostic systems. Science 1988;240:1285-1293. https://doi.org/10.1126/science.3287615
  40. Bland JM, Altman DG. Cronbach's alpha. BMJ 1997;314:572. https://doi.org/10.1136/bmj.314.7080.572
  41. Ferketich S. Focus on psychometrics. Aspects of item analysis. Res Nurs Health 1991;14:165-168. https://doi.org/10.1002/nur.4770140211
  42. Johns MW. Daytime sleepiness, snoring, and obstructive sleep apnea. The Epworth Sleepiness Scale. Chest 1993;103:30-36. https://doi.org/10.1378/chest.103.1.30
  43. Sanford SD, Lichstein KL, Durrence HH, Riedel BW, Taylor DJ, Bush AJ. The influence of age, gender, ethnicity, and insomnia on Epworth sleepiness scores: a normative US population. Sleep Med 2006;7:319-326. https://doi.org/10.1016/j.sleep.2006.01.010

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  80. Moderating Effect of Gender in the Relationship between Depression and Waketime Procrastination in Insomnia Patients vol.10, pp.2, 2014, https://doi.org/10.17241/smr.2019.00472
  81. Factor Analysis of the Insomnia Severity Index and Epworth Sleepiness Scale in Shift Workers vol.34, pp.50, 2019, https://doi.org/10.3346/jkms.2019.34.e317
  82. Effects of Sihogayonggolmoryeo-tang (Saikokaryukotsuboreito or Chai-Hu-Jia-Long-Gu-Mu-Li-Tang) for insomnia disorder with prehypertension or stage 1 hypertension : A study protocol for a randomized c vol.99, pp.29, 2014, https://doi.org/10.1097/md.0000000000020980
  83. Automatic Derivation of Continuous Positive Airway Pressure Settings: Comparison with In-Laboratory Titration vol.16, pp.2, 2020, https://doi.org/10.3988/jcn.2020.16.2.314
  84. Vitamin D Deficiency and Its Correlates in Migraine Patients vol.23, pp.2, 2014, https://doi.org/10.4103/aian.aian_229_19
  85. A combination of Eschscholtzia californica Cham. and Valeriana officinalis L. extracts for adjustment insomnia: A prospective observational study vol.10, pp.2, 2014, https://doi.org/10.1016/j.jtcme.2019.02.003
  86. Sex differences in factors associated with daytime sleepiness and insomnia symptoms in persons with epilepsy vol.104, pp.1, 2014, https://doi.org/10.1016/j.yebeh.2020.106919
  87. Time to Take Sleeping Pills and Subjective Satisfaction among Cancer Patients vol.17, pp.3, 2020, https://doi.org/10.30773/pi.2019.0216
  88. 불면증 변증도구 신뢰도와 타당도 평가 및 심리검사와의 상관성에 대한 초기연구 vol.31, pp.1, 2020, https://doi.org/10.7231/jon.2020.31.1.001
  89. Objective and subjective sleep problems and quality of life of rehabilitation in patients with mild to moderate stroke vol.27, pp.3, 2014, https://doi.org/10.1080/10749357.2019.1673591
  90. Psychometric properties of the Insomnia Severity Index in Ethiopian adults with substance use problems vol.19, pp.2, 2020, https://doi.org/10.1080/15332640.2018.1494658
  91. Sleep Status among Older Adults in Korea according to Urban or Rural Area Residence vol.17, pp.1, 2014, https://doi.org/10.13078/jsm.190051
  92. Smartphone Application Usage Patterns in Individuals with High Bedtime Procrastination: A Preliminary Study vol.17, pp.1, 2014, https://doi.org/10.13078/jsm.200002
  93. Sleep and Nocturia in Under Age 50 Male Patients with Obstructive Sleep Apnea Syndrome vol.17, pp.1, 2014, https://doi.org/10.13078/jsm.200009
  94. 주관적-객관적 수면시간 차이를 보이는 불면증 환자에서 일반적 불안에 비해 불면증 관련 자극으로 인한 뇌활성에 관한 기능적 자기공명영상 연구 vol.27, pp.1, 2014, https://doi.org/10.14401/kasmed.2020.27.1.24
  95. 중등도의 불면환자를 육미지황탕(六味地黃湯)(Liuwei Dihuang decoction)과 황련해독탕(黃連解毒湯)(Huanglian Jiedu Decoction) 병용 투여 및 배수혈 전침치료로 호전시킨 1례 : 증례보고 vol.41, pp.3, 2020, https://doi.org/10.22246/jikm.2020.41.3.494
  96. Evaluation of Sleep Quality and Psychological Profiles in Patients with Chronic Painful Temporomadibular Disorders vol.45, pp.2, 2014, https://doi.org/10.14476/jomp.2020.45.2.23
  97. Quality of Sleep and Quality of Life during Pregnancy vol.38, pp.3, 2020, https://doi.org/10.17340/jkna.2020.3.4
  98. Influence of group resilience on job satisfaction among Korean nurses: A cross‐sectional study vol.29, pp.17, 2020, https://doi.org/10.1111/jocn.15385
  99. Burnout as a Mediator in the Relationship between Work-Life Balance and Empathy in Healthcare Professionals vol.17, pp.9, 2014, https://doi.org/10.30773/pi.2020.0147
  100. Quality of sleep and quality of life measured monthly in pregnant women in South Korea vol.24, pp.3, 2014, https://doi.org/10.1007/s11325-020-02041-0
  101. Measures of Sleep in Rheumatologic Diseases: Sleep Quality Patient‐Reported Outcomes in Rheumatologic Diseases vol.72, pp.suppl10, 2014, https://doi.org/10.1002/acr.24238
  102. 중환자실 간호사의 수면장애가 피로, 졸음과 근접오류에 미치는 영향 vol.13, pp.3, 2014, https://doi.org/10.34250/jkccn.2020.13.3.1
  103. 교대근무 간호사의 혈액과 체액 노출 사고 예측 요인과 감염예방행위의 매개효과: 영과잉 가산 자료 분석방법을 적용하여 vol.50, pp.5, 2020, https://doi.org/10.4040/jkan.20025
  104. Alterations in Salience Network Functional Connectivity in Individuals with Restless Legs Syndrome vol.10, pp.None, 2014, https://doi.org/10.1038/s41598-020-64641-w
  105. Posttraumatic stress disorder and depression of survivors 12 months after the outbreak of Middle East respiratory syndrome in South Korea vol.20, pp.1, 2014, https://doi.org/10.1186/s12889-020-08726-1
  106. Efficacy of Cognitive Behavioral Treatment for Insomnia: A Randomized Controlled Trial vol.42, pp.12, 2014, https://doi.org/10.1177/0193945920914081
  107. Sleep and Cognitive Function in Shift Working Police Officers: Focusing on the Night Nap vol.17, pp.2, 2020, https://doi.org/10.13078/jsm.200011
  108. Sex Differences in Etiologies of Sleep Disorders vol.17, pp.2, 2014, https://doi.org/10.13078/jsm.200023
  109. The Mediating Effect of Depression in the Relationship between Sleep Misperception and Insomnia Severity among Insomnia Patients vol.17, pp.2, 2014, https://doi.org/10.13078/jsm.200029
  110. Depression and Sleep Quality of Obstetricians vol.11, pp.2, 2014, https://doi.org/10.17241/smr.2020.00626
  111. 수면다원검사를 적용한 호흡관련 수면장애 한약 치료 3례 증례 보고 vol.31, pp.4, 2014, https://doi.org/10.7231/jon.2020.31.4.329
  112. 수면 제품 실증을 위한 수면-각성 평가에 대한 고찰 vol.27, pp.2, 2014, https://doi.org/10.14401/kasmed.2020.27.2.51
  113. Successful treatment of restless leg syndrome with the traditional herbal medicines Dangguijakyak-san and Shihogyeji-tang : A case report (CARE-compliant) vol.100, pp.31, 2021, https://doi.org/10.1097/md.0000000000026800
  114. The Safety and Efficacy of Pregabalin Add-on Therapy in Restless Legs Syndrome Patients vol.12, pp.None, 2014, https://doi.org/10.3389/fneur.2021.786408
  115. The Impact of Tinnitus on Fibromyalgia vol.28, pp.1, 2014, https://doi.org/10.4078/jrd.2021.28.1.31
  116. Risk Perception, Unhealthy Behavior, and Anxiety Due to Viral Epidemic Among Healthcare Workers: The Relationships With Depressive and Insomnia Symptoms During COVID-19 vol.12, pp.None, 2014, https://doi.org/10.3389/fpsyt.2021.615387
  117. Associations Between COVID-19 Symptoms and Psychological Distress vol.12, pp.None, 2021, https://doi.org/10.3389/fpsyt.2021.721532
  118. The Association Between the Number of Consecutive Night Shifts and Insomnia Among Shift Workers: A Multi-Center Study vol.9, pp.None, 2014, https://doi.org/10.3389/fpubh.2021.761279
  119. Relationship Between Shift Intensity and Insomnia Among Hospital Nurses in Korea: A Cross-sectional Study vol.54, pp.1, 2014, https://doi.org/10.3961/jpmph.20.555
  120. The Mediating Effect of Insomnia on the Relationship between Panic Symptoms and Depression in Patients with Panic Disorder vol.36, pp.9, 2014, https://doi.org/10.3346/jkms.2021.36.e30
  121. COVID-19 가 생활치료센터 입소자들의 라이프스타일, 건강, 삶의 질에 미치는 영향: 혼합연구방법을 활용한 연구 vol.10, pp.1, 2014, https://doi.org/10.22683/tsnr.2021.10.1.077
  122. 여고생의 월경곤란증 실태 및 그 영향 요인 vol.12, pp.3, 2014, https://doi.org/10.15207/jkcs.2021.12.3.409
  123. Effect of Light Emitted by Smartphones at Bedtime on Circadian Rhythm and Sleep: Is It Different between Day Worker and Shift Worker? vol.18, pp.1, 2021, https://doi.org/10.13078/jsm.210003
  124. Development and Validation of a Semi-Structured Clinical Interview for Nightmare Disorder vol.18, pp.1, 2021, https://doi.org/10.13078/jsm.210004
  125. Association between stress and dietary habits, emotional eating behavior and insomnia of middle-aged men and women in Seoul and Gyeonggi vol.15, pp.2, 2014, https://doi.org/10.4162/nrp.2021.15.2.225
  126. Associations between lower back pain and job types in South Korean male firefighters vol.27, pp.2, 2014, https://doi.org/10.1080/10803548.2019.1608061
  127. 치과보철치료를 요하는 환자에서의 수면질과 스트레스 반응 평가 vol.59, pp.2, 2014, https://doi.org/10.4047/jkap.2021.59.2.181
  128. Reduced sympatho-vagal responses to orthostatic stress in drug-naïve idiopathic restless legs syndrome vol.17, pp.5, 2014, https://doi.org/10.5664/jcsm.9074
  129. Effect of herbal medicine ( Huanglian-jie-du granule) for somatic symptoms and insomnia in patients with Hwa-byung : A randomized controlled trial vol.10, pp.2, 2014, https://doi.org/10.1016/j.imr.2020.100453
  130. Prevalence of Insomnia in Various Industries and Associated Demographic Factors in Night-Shift Workers Using Workers’ Specific Health Examination Data vol.18, pp.13, 2014, https://doi.org/10.3390/ijerph18136902
  131. The prevalence and clinical characteristics of restless legs syndrome in patients with iron deficiency anemia in Korea vol.17, pp.7, 2014, https://doi.org/10.5664/jcsm.9230
  132. Bath Ankylosing Spondylitis Disease Activity Index is Associated With the Quality of Sleep in Ankylosing Spondylitis Patients vol.28, pp.3, 2014, https://doi.org/10.4078/jrd.2021.28.3.143
  133. Randomized, placebo-controlled trial of ferric carboxymaltose in restless legs syndrome patients with iron deficiency anemia vol.84, pp.None, 2014, https://doi.org/10.1016/j.sleep.2021.05.036
  134. Effects of Probiotic NVP-1704 on Mental Health and Sleep in Healthy Adults: An 8-Week Randomized, Double-Blind, Placebo-Controlled Trial vol.13, pp.8, 2014, https://doi.org/10.3390/nu13082660
  135. Advanced Cognitive Behavioral Therapy for Insomnia (CBT-I) Based on Acceptance and Commitment Therapy Compared With CBT-I: A Pilot Study vol.18, pp.2, 2014, https://doi.org/10.13078/jsm.210002
  136. 순환교대근무 간호사의 일주기유형에 따른 근무조별 수면시간, 사회적 시차, 주관적 수면장애 비교 vol.23, pp.3, 2014, https://doi.org/10.7586/jkbns.2021.23.3.227
  137. Sleep Disturbances and Phenoconversion in Patients with REM Sleep Behavior Disorder vol.10, pp.20, 2014, https://doi.org/10.3390/jcm10204709
  138. Smartphone Addiction Proneness Is Associated With Subjective-Objective Sleep Discrepancy in Patients With Insomnia Disorder vol.18, pp.11, 2021, https://doi.org/10.30773/pi.2020.0360
  139. Cardiac Autonomic Dysfunction Is Associated with Severity of REM Sleep without Atonia in Isolated REM Sleep Behavior Disorder vol.10, pp.22, 2014, https://doi.org/10.3390/jcm10225414
  140. Contributing Factors of Excessive Daytime Sleepiness in Morbid Obese Patients with Obstructive Sleep Apnea vol.39, pp.4, 2014, https://doi.org/10.17340/jkna.2021.4.5
  141. Structural validity of the Insomnia Severity Index: A systematic review and meta-analysis vol.60, pp.None, 2014, https://doi.org/10.1016/j.smrv.2021.101531
  142. Insomnia moderates the association between recurrent seizures and emotional instability in persons with epilepsy vol.125, pp.None, 2014, https://doi.org/10.1016/j.yebeh.2021.108414
  143. Brain reactivity using fMRI to insomnia stimuli in insomnia patients with discrepancy between subjective and objective sleep vol.11, pp.1, 2014, https://doi.org/10.1038/s41598-021-81219-2
  144. Effects of subjective-objective sleep discrepancy on the response to cognitive behavior therapy for insomnia vol.152, pp.None, 2014, https://doi.org/10.1016/j.jpsychores.2021.110682