1. Jiang SM, Jia L, Lei XG, et al. Incidence and psychological-behavioral char- acteristics of refractory functional dyspepsia: a large, multi-center, pro- spective investigation from China. World J Gastroenterol. 2015;21:1932–7.
2. Tu Q, Heitkemper MM, Jarrett ME, et al. Sleep disturbances in irrita- ble bowel syndrome: a systematic review. Neurogastroenterol Motil. 2017;29:e12946.
3. Lei WY, Chang WC, Wong MW, et al. Sleep disturbance and its association with gastrointestinal symptoms/diseases and psychological comorbidity. Digestion. 2019;99:205–12.
4. Futagami S, Yamawaki H, Izumi N, et al. Impact of sleep disorders in Japanese patients with functional dyspepsia (FD): nizatidine improves clinical symptoms, gastric emptying and sleep disorders in FD patients. J Gastroenterol Hepatol. 2013;28:1314–20.
5. Kim SY, Choung RS, Lee SK, et al. Self-reported sleep impairment in functional dyspepsia and irritable Bowel syndrome. J Neurogastroenterol Motil. 2018;24:280–8.
6. Klupinska G, Poplawski T, Drzewoski J, et al. Therapeutic effect of melatonin in patients with functional dyspepsia. J Clin Gastroenterol. 2007;41:270–4.
7. Zybach K, Friesen CA, Schurman JV. Therapeutic effect of melatonin on pediatric functional dyspepsia: a pilot study. World J Gastrointest Pharma- col Ther. 2016;7:156–61.
8. Schey R, Dickman R, Parthasarathy S, et al. Sleep deprivation is hyperal- gesic in patients with gastroesophageal reflux disease. Gastroenterology. 2007;133:1787–95.
9. Jha LK, Fass R, Gadam R, et al. The effect of ramelteon on heartburn symptoms of patients with gastroesophageal reflux disease and chronic insomnia: a pilot study. J Clin Gastroenterol. 2016;50:e19-24.
10. Stanghellini V, Chan FK, Hasler WL, et al. Gastroduodenal disorders. Gas- troenterology. 2016;150:1380–92.
11. Doi Y, Minowa M, Uchiyama M, et al. Psychometric assessment of subjec- tive sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects. Psychiatry Res. 2000;97:165–72.
12. Rossi A, Stratta P, D’Albenzio L, et al. Reduced temporal lobe area in schizophrenia by magnetic resonance imaging: preliminary evidence. Psychiatry Res. 1989;29:261–3.
13. Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep. 1991;14:540–5.
14. Takegami M, Suzukamo Y, Wakita T, et al. Development of a Japanese version of the Epworth Sleepiness Scale (JESS) based on item response theory. Sleep Med. 2009;10:556–65.
15. 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.
16. Soldatos CR, Dikeos DG, Paparrigopoulos TJ. The diagnostic validity of the Athens Insomnia Scale. J Psychosom Res. 2003;55:263–7.
17. Okajima I, Nakajima S, Kobayashi M, et al. Development and validation of the Japanese version of the Athens Insomnia Scale. Psychiatry Clin Neurosci. 2013;67:420–5.
18. Kusano M, Shimoyama Y, Sugimoto S, et al. Development and evalua- tion of FSSG: frequency scale for the symptoms of GERD. J Gastroenterol. 2004;39:888–91.
19. Kusano M, Hosaka H, Kawada A, et al. Development and evaluation of a modified Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease to distinguish functional dyspepsia from non-erosive reflux disease. J Gastroenterol Hepatol. 2012;27:1187–91.
20. Revicki DA, Wood M, Wiklund I, et al. Reliability and validity of the Gastro- intestinal Symptom Rating Scale in patients with gastroesophageal reflux disease. Qual Life Res. 1998;7:75–83.
21. Agachan F, Chen T, Pfeifer J, et al. A constipation scoring system to simplify evaluation and management of constipated patients. Dis Colon Rectum. 1996;39:681–5.
22. McShane RE, McLane AM. Constipation. Consensual and empirical valida- tion. Nurs Clin North Am. 1985;20:801–8.
23. Nomura H, Agatsuma T, Mimura T. Validity and reliability of the Japanese version of the Patient Assessment of Constipation Quality of Life ques- tionnaire. J Gastroenterol. 2014;49:667–73.
24. Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983;67:361–70.
25. Kugaya A, Akechi T, Okuyama T, et al. Screening for psychological distress in Japanese cancer patients. Jpn J Clin Oncol. 1998;28:333–8.
26. Fukuhara S, Bito S, Green J, et al. Translation, adaptation, and valida- tion of the SF-36 Health Survey for use in Japan. J Clin Epidemiol. 1998;51:1037–44.
27. Lie JD, Tu KN, Shen DD, et al. Pharmacological treatment of insomnia. Pharm Ther. 2015;40:759–71.
28. Ramirez AD, Gotter AL, Fox SV, et al. Dual orexin receptor antagonists show distinct effects on locomotor performance, ethanol interaction and sleep architecture relative to gamma-aminobutyric acid-A receptor modulators. Front Neurosci. 2013;7:254.
29. Uslaner JM, Tye SJ, Eddins DM, et al. Orexin receptor antagonists differ from standard sleep drugs by promoting sleep at doses that do not disrupt cognition. Sci Transl Med. 2013;5:179ra44.
30. Moayyedi P, Soo S, Deeks J, et al. Eradication of helicobacter pylori for non-ulcer dyspepsia. Cochrane Database Syst Rev. 2006;2:CD002096.
31. Kimura K, Takemoto T. An endoscopic recognition of the atrophic border and its significance in chronic gastritis. Endoscopy. 1969;3:87–97.
32. Sakae H, Iwamuro M, Okamoto Y, et al. Evaluation of the usefulness and convenience of the Kyoto classification of gastritis in the endo- scopic diagnosis of the helicobacter pylori infection status. Digestion. 2020;101:771–8.
33. Yoshii S, Mabe K, Watano K, et al. Validity of endoscopic features for the diagnosis of Helicobacter pylori infection status based on the Kyoto clas- sification of gastritis. Dig Endosc. 2020;32:74–83.
34. Stacher G, Starker D. Inhibitory effect of bromazepam on basal and betazole-stimulated gastric acid secretion in man. Gut. 1974;15:116–20.
35. Levine AS, Morley JE, Kneip J, et al. Muscimol induces gastric acid secre- tion after central administration. Brain Res. 1981;229:270–4.
36. Goto Y, Debas HT. GABA-mimetic effect on gastric acid secretion. Possible significance in central mechanisms. Dig Dis Sci. 1983;28:56–9.
37. Goto Y, Tache Y, Debas H, et al. Gastric acid and vagus nerve response to GABA agonist baclofen. Life Sci. 1985;36:2471–5.
38. Tsai LH, Taniyama K, Tanaka C. gamma-Aminobutyric acid stimulates acid secretion from the isolated guinea pig stomach. Am J Physiol. 1987;253:G601–6.
39. Del Tacca M, Blandizzi C, Bernardini MC. Central GABAA excitatory and GABAB inhibitory receptors regulate gastric acid secretion in rats. Eur J Pharmacol. 1990;177:189–94.
40. MacNaughton WK, Pineau BC, Krantis A. gamma-Aminobutyric acid stimulates electrolyte transport in the guinea pig ileum in vitro. Gastroen- terology. 1996;110:498–507.
41. Williford DJ, Ormsbee HS 3rd, Norman W, et al. Hindbrain GABA recep- tors influence parasympathetic outflow to the stomach. Science. 1981;214:193–4.
42. Horita T, Koyama K, Takemi S, et al. GABAergic and glutamatergic neurons in the brain regulate phase II of migrating motor contractions in the Suncus murinus. J Smooth Muscle Res. 2018;54:91–9.
43. Rode F, Jensen DG, Blackburn-Munro G, et al. Centrally-mediated antino- ciceptive actions of GABA(A) receptor agonists in the rat spared nerve injury model of neuropathic pain. Eur J Pharmacol. 2005;516:131–8.
44. Mirza NR, Munro G. The role of GABA(A) receptor subtypes as analgesic targets. Drug News Perspect. 2010;23:351–60.
45. Munro G, Hansen RR, Mirza NR. GABA(A) receptor modulation: potential to deliver novel pain medicines? Eur J Pharmacol. 2013;716:17–23.
46. Sengupta JN, Pochiraju S, Kannampalli P, et al. MicroRNA-mediated GABA Aalpha-1 receptor subunit down-regulation in adult spinal cord following neonatal cystitis-induced chronic visceral pain in rats. Pain. 2013;154:59–70.
47. Bengtsson MW, Makela K, Sjoblom M, et al. Food-induced expression of orexin receptors in rat duodenal mucosa regulates the bicarbonate secretory response to orexin-A. Am J Physiol Gastrointest Liver Physiol. 2007;293:G501–9.
48. Takahashi N, Okumura T, Yamada H, et al. Stimulation of gastric acid secretion by centrally administered orexin-A in conscious rats. Biochem Biophys Res Commun. 1999;254:623–7.
49. Kirchgessner AL, Liu M. Orexin synthesis and response in the gut. Neuron. 1999;24:941–51.
50. Kobashi M, Furudono Y, Matsuo R, et al. Central orexin facilitates gastric relaxation and contractility in rats. Neurosci Lett. 2002;332:171–4.
51. Krowicki ZK, Burmeister MA, Berthoud HR, et al. Orexins in rat dorsal motor nucleus of the vagus potently stimulate gastric motor function. Am J Physiol Gastrointest Liver Physiol. 2002;283:G465–72.
52. Ida T, Nakahara K, Murakami T, et al. Possible involvement of orexin in the stress reaction in rats. Biochem Biophys Res Commun. 2000;270:318–23.
53. Heidari-Oranjaghi N, Azhdari-Zarmehri H, Erami E, et al. Antagonism of orexin-1 receptors attenuates swim- and restraint stress-induced antinociceptive behaviors in formalin test. Pharmacol Biochem Behav. 2012;103:299–307.
54. Lee MT, Chiu YT, Chiu YC, et al. Neuropeptide S-initiated sequential cascade mediated by OX1, NK1, mGlu5 and CB1 receptors: a pivotal role in stress-induced analgesia. J Biomed Sci. 2020;27:7.
55. Okumura T, Nozu T, Kumei S, et al. Antinociceptive action against colonic distension by brain orexin in conscious rats. Brain Res. 2015;1598:12–7.
56. Michelson D, Snyder E, Paradis E, et al. Safety and efficacy of suvorexant during 1-year treatment of insomnia with subsequent abrupt treatment discontinuation: a phase 3 randomised, double-blind, placebo-controlled trial. Lancet Neurol. 2014;13:461–71.
57. Andersen ML, Araujo P, Frange C, et al. Sleep disturbance and pain: a tale of two common problems. Chest. 2018;154:1249–59.
58. Teh KK, Ng YK, Doshi K, et al. Mindfulness-based cognitive therapy in functional dyspepsia: A pilot randomized trial. J Gastroenterol Hepatol 2020 (in press).
59. Tavakoli T, Hoseini M, Tabatabaee TSJ, et al. Comparison of dialectical behavior therapy and anti-anxiety medication on anxiety and diges- tive symptoms in patients with functional dyspepsia. J Res Med Sci. 2020;25:59.
60. Trauer JM, Qian MY, Doyle JS, et al. Cognitive behavioral therapy for chronic insomnia: a systematic review and meta-analysis. Ann Intern Med. 2015;163:191–204.
61. Kim SE, Park HK, Kim N, et al. Prevalence and risk factors of functional dyspepsia: a nationwide multicenter prospective study in Korea. J Clin Gastroenterol. 2014;48:e12–8.
62. Kim YS, Kim N. Functional dyspepsia: a narrative review with a focus on sex-gender differences. J Neurogastroenterol Motil. 2020;26:322–34.
63. Mori H, Suzuki H, Matsuzaki J, et al. Gender difference of gastric emptying in healthy volunteers and patients with functional dyspepsia. Digestion. 2017;95:72–8.
64. Chial HJ, Camilleri C, Delgado-Aros S, et al. A nutrient drink test to assess maximum tolerated volume and postprandial symptoms: effects of gender, body mass index and age in health. Neurogastroenterol Motil. 2002;14:249–53.
65. Meerveld BG, Johnson AC. Mechanisms of stress-induced visceral pain. J Neurogastroenterol Motil. 2018;24:7–18.
66. Hellstrom B, Anderberg UM. Pain perception across the menstrual cycle phases in women with chronic pain. Percept Mot Skills. 2003;96:201–11.
67. Shinomiya T, Fukunaga M, Akamizu T, et al. Plasma acylated ghrelin levels correlate with subjective symptoms of functional dyspepsia in female patients. Scand J Gastroenterol. 2005;40:648–53.
68. Choi YJ, Park YS, Kim N, et al. Gender differences in ghrelin, nociception genes, psychological factors and quality of life in functional dyspepsia. World J Gastroenterol. 2017;23:8053–61.
69. Zeng F, Sun R, He Z, et al. Altered functional connectivity of the amygdala and sex differences in functional dyspepsia. Clin Transl Gastroenterol. 2019;10:e00046.
70. Raahave D, Loud FB. Additional faecal reservoirs or hidden constipation: a link between functional and organic bowel disease. Dan Med Bull. 2004;51:422–5.