Psychiatry Investig Search


Psychiatry Investig > Volume 15(12); 2018 > Article
Cho, Jung, Kapczinski, Rosa, and Lee: Validation of the Korean Version of the Biological Rhythms Interview of Assessment in Neuropsychiatry



The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) is a scale used to clinically evaluate disturbances in biological rhythm. In this study, we aimed to examine the reliability and validity of the Korean version of the BRIAN (K-BRIAN) in a Korean population.


A total of 181 participants, including 141 outpatients with bipolar disorder (BD; type I, 62; type II, 79) and 40 controls, were recruited. Construct validity was tested by comparing the mean K-BRIAN scores of the BD patients and control subjects. Concurrent validity was tested by evaluating the association between the K-BRIAN and the Morningness-Eveningness Questionnaire (MEQ).


The mean K-BRIAN scores of the control subjects and patients with BD differed significantly (p<0.001). Particularly, the mean K-BRIAN score was considerably lower among control subjects (mean±standard deviation=35.00±8.88) than among patients with BD type I (41.19±12.10) and type II (50.18±13.73). The Cronbach’s alpha for the K-BRIAN was 0.914. The K-BRIAN was found to correlate with the MEQ (r=-0.45, p<0.001).


The findings affirm that the K-BRIAN has good construct validity and internal consistency. This suggests that the K-BRIAN can be used to assess biological rhythms in the Korean population, especially for patients with mood disorder.


The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) was developed to clinically assess disturbances in biological rhythm, particularly in patients with mental disorders [1]. Patients with mood disorders frequently experience circadian rhythm dysregulation, which includes irregular restactivity cycle patterns, abnormal hormone secretion, social rhythm disruptions, and sleep-wake disturbances [2,3]. The scale aims to measure rhythm impairment in 5 different domains directly related to an individual’s daily functioning [1]. These domains include sleep, activity, social rhythms, and eating pattern [1]. The scale comprises 18 items, including additional 3 items to determine the predominant rhythm, and all items are scored on a 4-point scale [1]. The item scores are summed during the final evaluation, and the total scores for the 18 items range from 18 to 72 [1]. A higher score indicates a more severe biological rhythm disturbance [1]. Currently, the scale is applied as an interviewer-administered questionnaire and has been validated in three different languages that include Portuguese, Spanish, Italian, and English [1,4-6].
Many studies have hypothesized that identifying the link between biological rhythm disturbances and mood disorders may help to explain the etiology of mood disorders, including bipolar disorder (BD) and depressive disorders [3,7-9]. Reports have described associations between circadian rhythm abnormalities and mood disorders, given that circadian rhythm desynchronization plays a substantial role in the emergence of sleep disturbances that are closely associated with mood symptoms [10-12]. Sleep-wake cycle irregularities are commonly observed in patients with mood disorders [13]. Additionally, shifts in molecular circadian rhythm phases have been reported in patients with BD in whom phase delays and advances have been associated with different mood episodes, including depressive, manic, and mixed [2,3]. Accordingly, some chronotherapeutic interventions developed to adjust circadian misalignments, such as bright light therapy (BLT), management of a regular sleep-wake cycle, and interpersonal and social rhythm therapy (IPSRT), have been used successfully to reduce the severity of BD [3,14-16]. Moreover, the therapeutic mechanisms of lithium and valproate, which are frequently prescribed for the treatment of BD, have been attributed to the influences of these drugs on circadian genes and molecular clocks via the inhibition of glycogen synthase kinase-3β [17,18].
Therefore, a biological rhythm assessment is not only important for identifying the cause of clinical symptoms, but also for the psychiatric treatment and clinical research of mood disorders. Currently, scales such as Seasonal Pattern Assessment Questionnaire (SPAQ) [19] and Morningness-Eveningness Questionnaire (MEQ) [20] are available for evaluating biological rhythm. However, these scales specifically evaluate chronotype or seasonality and are not sufficient for the direct evaluation of a subject’s biological rhythm. Given the increasing emphasis on the importance of biological rhythm in the psychiatric field, the BRIAN was developed with a focus on biological rhythm and is considered highly valuable in research and clinical studies.
The objectives of this study were to examine the reliability and validity of the Korean version of the BRIAN (K-BRIAN) by examining the relevance of the scale for identifying circadian rhythm abnormalities. This study acknowledges the clinical relationship of circadian rhythm disturbances with the clinical manifestations of BD. The study was performed under the assumption that the preferred circadian phase may predict sleep and circadian rhythm alterations in patients with BD, given that previous studies have reported a greater circadian preference towards eveningness in many patients with BD types I and II [8-10,13,21-23]. Accordingly, we adopted another measure, the MEQ [20], to test the concurrent validity of the K-BRIAN.



One hundred and forty-one patients with a clinical diagnosis of BD under a subsyndromic clinical condition according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [24] were recruited at 9 different hospitals participating in the Mood Disorder Cohort Research Consortium (MDCRC) study [25], including Korea University Anam Hospital, Seoul National University Hospital, Seoul National University Bundang Hospital, Samsung Medical Center, Severance Hospital, Pusan National University Hospital, Gyeongsang National University Hospital, Cheonnam National University Hospital, and the National Center for Mental Health. Cases were diagnosed using the Mini-International Neuropsychiatric Interview (M.I.N.I.) [26]. Sixty-nine subjects were diagnosed with BD I; the remaining subjects were diagnosed with BD II.
Forty control subjects were drawn randomly from the general population at Korea University Anam Hospital. The control group was balanced in terms of age and sex. In this group [1], male subject was later excluded from the reliability analysis because he failed to answer all questions from the K-BRIAN during the retest assessment.
Informed consent was obtained from all subjects prior to the study. The research was approved by the Institutional Review Board of the Korea University Anam Hospital (IRB No. 2015AN0239) and conducted in accordance with the Declaration of Helsinki.


The BRIAN comprises 18 items divided into 4 main areas related to circadian rhythm disturbances: sleep, social rhythms, activity, and eating pattern. Three additional items addressed predominant rhythm (i.e., chronotype). Particularly, the BRIAN assesses the frequency of problems related to the maintenance of a regular circadian rhythm. The total BRIAN scores from the 18 items range from 18 to 72, with higher scores indicating a more severe circadian rhythm disturbance. The BRIAN has been used in previous studies conducted in Brazil [1], Spain [27,28], and Canada [29].
The BRIAN was translated from English to Korean by a lead researcher of the MDCRC. Forward-backward translations were used to maintain linguistic and conceptual equivalence. The K-BRIAN can be found in Supplementary Material (in the online-only Data Supplement). Prior to our work with the K-BRIAN, we received approval from the original author, Dr. Kapczinski [1], and continued to discuss our progress with this author throughout the study.
The K-BRIAN was applied to the 141 patients with BD and 40 control subjects recruited for our study. Patients with BD were simultaneously evaluated using the MEQ scale [20] and K-BRIAN. These scales were to compare the abilities of these tests to determine chronotypes. The MEQ scale was designed to evaluate chronotype preferences in individuals. It includes 19 items for which all scores are summed in the evaluation. Subjects with higher scores are more likely to be categorized as the morning type, whereas those with lower scores tend to be categorized as the evening type. As previously mentioned, this study presumed that the eveningness chronotype may be used as preliminary evidence in an evaluation of circadian rhythm alterations, as this characteristic is prominent among individuals with BD or other mood disorders [8-10,13,21,30]. Additionally, the reliability of K-BRIAN was determined in a test-retest evaluation involving 40 control subjects. These subjects were evaluated twice at 4-week intervals, and the time points were identified as pre- and post-K-BRIAN. One male control subject failed to complete the post-K-BRIAN.

Statistical analyses

SPSS 18.0 for Windows (SPSS Inc., Chicago, IL, USA) was used to perform the statistical analysis. First, a 1-way analysis of variance (ANOVA) was used to test the construct validity of the K-BRIAN. The mean K-BRIAN scores of the patients with BD and control subjects were compared to examine whether the scale could determine abnormalities in biological rhythms among the former group. Second, the associations between the K-BRIAN and MEQ were analyzed by comparing the mean K-BRIAN and MEQ scores of the patients with BD. The concurrent validity of these scales was evaluated using a Pearson’s correlation analysis. Third, Cronbach’s alpha was used to evaluate the internal consistency of the K-BRIAN. The test-retest reliability of the pre- and post-K-BRIAN scores of the control group were compared using the paired samples t-test.


Subject characteristics

The subjects’ demographics were analyzed using descriptive statistics (Table 1). The mean (±standard deviation) ages of patients with BD types I and II were 23.32±2.66 and 22.87±2.70 years, respectively. There were slightly more female than male subjects among all patients with BD types I and II. The mean K-BRIAN score was higher among patients with BD type II (50.18±13.73) than among patients with BD type I (41.19±12.10). However, patients with BD type II received lower MEQ scores, compared to those with BD type I. As predicted, the eveningness chronotype was predominant in both groups.
The control group had a mean age of 24.76±4.46 years, similar to that of BD patients. In this group, the male/female ratio was exactly 50/50 because the control subjects were balanced in terms of sex. The mean K-BRIAN and MEQ scores among controls were 36.43±9.54 and 35.00±8.88, respectively. As in the BD groups, the eveningness chronotype was predominant in the control group.

Comparison of K-BRIAN scores between patients with BD and control subjects

As shown in Table 2, the ANOVA revealed significant differences in BRIAN scores (F=22.43, p<0.001) among the 3 different groups (BD types I and II and controls). Post hoc comparisons (Tukey HSD test) also indicated a significantly lower mean K-BRIAN score for control subjects than for patients with BD type I (p<0.036) and BD type II (p<0.001). Furthermore, the mean K-BRIAN score among patients with BD type II was significantly higher than those among patients with BD type I (p<0.001) and control subjects (p<0.001). This pattern remained when the 5 different domains of the BRIAN were analyzed separately (Table 3). The mean scores for each domain of the BRIAN revealed an increasing pattern dependent on the severity of the biological rhythm disruption. Specifically, higher BRIAN scores indicated greater overall biological rhythm disturbances, especially among patients with BD.

Analysis of the correlation between K-BRAIN and MEQ

The analysis revealed a negative correlation between the 2 scales. A linear correlation was observed between these variables such that the MEQ score decreased as the BRIAN score increased. This pattern was expected because a low MEQ score indicates an eveningness chronotype, while a high BRIAN score reveals biological rhythm disturbances. The correlation had an approximately moderate magnitude or strength and was statistically significant (r=-0.45, p<0.001).

Reliability statistics of K-BRIAN

The K-BRIAN was found to be highly reliable for the evaluation of patients with BD. The Cronbach’s alpha value of 0.914 indicated a high level of internal consistency for this scale (Table 4). A test-retest reliability analysis of 39 control subjects revealed a moderate correlation (r=0.46, p<0.001) between the pre- (34.62±8.66) and post-K-BRIAN scores (33.59±6.92). A paired samples t-test revealed no significant intragroup difference between these pre- and post-K-BRAIN scores (t=0.775, p=0.443).


We studied the validity and reliability of the K-BRIAN, which has been used to measure biological rhythm in psychiatric settings. Particularly, subjects with BD, which is known to associate closely with circadian rhythm disturbances, were compared with control subjects, and a significant intergroup difference was confirmed. The reliability of the K-BRIAN, confirmed through this study, was similar to that determined in previous studies of BRIAN [1,4]. The Cronbach’s alpha values for the entire scale and for each item were very good and additionally confirmed the excellent reliability of K-BRIAN.
Biological rhythm can be measured at several stages. The traditional method involves continuous measurement of the core body temperature [31]; however, most approaches evaluate molecular and behavioral circadian rhythms, wherein the former can be confirmed by measuring changes in gene expression or hormone secretion and the latter can be measured using actigraphy or wearable devices [12,32-35]. Molecular-level measurements may be most accurate; however, this method remains cumbersome and invasive and is difficult to apply to a large number of subjects. Furthermore, although actigraphy or wearable devices can provide valuable behavior pattern-based information related to biological rhythms, it is difficult to obtain this information directly without wearing a device. A biological rhythm measurement based on the K-BRIAN scale is subject to recall bias and dependent on the reliability of answers [36,37], but can be easily evaluated at any time; furthermore, the ability to assess 5 subdomains makes this scale an attractive clinical and research tool. Particularly, given the changes in seasonal characteristics throughout the year and the increased disturbance of circadian rhythms due to increased nighttime light exposure, a consequence of a significantly modernized and developed lifestyle [38,39], the K-BRIAN can be useful for measuring disturbances in biological rhythm in a psychiatric context in Korea.
In the present study, the K-BRIAN score was significantly higher in patients with BD than in normal controls. This is consistent with previous studies suggesting that patients with BD exhibit more disturbed biological rhythms as determined by the BRIAN [8]. Particularly, the higher K-BRIAN score of patients with BD type II relative to those with type I suggests a stronger association of the former type with biological rhythm disturbances [30]. This result can be interpreted in the context of previous studies, which reported a close relationship between biological rhythm disturbances and more frequent and severe depressive features in patients with BD II [27,28]. Further investigation into the relationship between the frequency and severity of mood symptoms and the K-BRIAN will be needed in future. This finding provides important evidence regarding an approach based on biological rhythms in mood disorders research and clinical practices.
The correlation between the MEQ and K-BRIAN was significant and negative and suggested a reasonable degree of concurrent validity. In other words, the lower the MEQ score, the higher the K-BRIAN score. This finding suggests a possible relationship between a biological rhythm disturbance and the eveningness chronotype. Studies have shown that the eveningness chronotype is closely related to BD or seasonal affective disorder (SAD) [40-42]. From this study, the eveningness chronotype appears more likely to disturb the biological rhythm, and both characteristics are closely related to BD. Patients with the eveningness chronotype often remain awake at night and are very likely to be exposed to inappropriate and unnecessary light while awake. A previous study reported that the molecular circadian rhythms of patients at a high-risk of mood disorder are much more easily disturbed by nighttime light exposure than those of patients at a low-risk [12]. The absence of the morningness chronotype and relatively high frequency of the eveningness chronotype on the MEQ in this study indicates changes in the lifestyles of modern Korean residents. This suggests that circadian rhythm vulnerability and rhythm disturbance factors such as nighttime light exposure, which is common among individuals with the eveningness chronotype, may induce and aggravate BD.
This study had some limitations. First, the study sample was relatively small. However, the combined group of patients with BD types I and II included a considerable number of subjects, which was superior to the sample sizes of previous BRIAN-related studies [1,4]. Second, it was difficult to select a scale for comparison with K-BRIAN. Previous studies of BRIAN used the same sleep scale as Pittsburgh Sleep Quality Assessment (PSQI) [1]; however, we selected the MEQ to address biological rhythm [20]. Although a tool with a stronger focus on biological rhythm would be a better option, the MEQ is currently the best-available comparison tool.
In this study, we validated the Korean version of the BRIAN, a scale actively used for biological rhythm measurements in a psychiatric context, and confirmed its validity and reliability in a Korean population. Notably, we observed a significantly higher K-BRIAN score in patients with BD than in normal subjects and confirmed a significant correlation of this scale with the MEQ. Despite some limitations of the K-BRIAN for evaluating biological rhythms, it appears to be a very useful tool for evaluation because it focuses on biological rhythms, unlike other scales that only indirectly measure biological rhythm by evaluating seasonality or chronotype. In the future, the K-BRIAN will likely be used for biological rhythm measurements in various psychiatric areas and for active research and clinical practice pertaining to mood disorders.

Supplementary Materials

The online-only Data Supplement is available with this article at


This study was supported by the Korea Health 21 R&D Project, funded by the Ministry of Health & Welfare, Republic of Korea (HM14C2606) and by the National Research Foundation of Korea (2016M3C7A1904345 and 2017M3A9F1031220).

Table 1.
Characteristics of the study subjects
BD I (N=62) BD II (N=79) Control subjects (N=40)
Age (year) 23.32±2.66 22.87±2.70 24.76±4.46
Sex (M/F) 43.5/56.5 (%) 44.3/55.7 (%) 50/50 (%)
Mean K-BRIAN score 41.19±12.10 50.18±13.73 36.43±9.54
Mean MEQ score 33.74±8.22 28.46±7.82 35.00±8.88
 Eveningness 51 76 36
 Intermediate 11 3 4
 Morningness 0 0 0

Values are presented as means±standard deviations. BD: bipolar disorder, M: male, F: female, K-BRIAN: Korean version of the biological rhythms interview of assessment in neuropsychiatry, MEQ: morningness-eveningness questionnaire

Table 2.
One-way analysis of variance of mean K-BRIAN scores between BD patients and control subjects
Source df SS MS F p
Between groups 2 6731.11 3365.56 22.43 <0.001
Within groups 178 26713.20 150.07 - -
Total 180 33444.31 - - -

K-BRIAN: Korean version of the biological rhythms interview of assessment in neuropsychiatry, BD: bipolar disorder, df: degrees of freedom, SS: sum of squares, MS: mean square, F: f statistic, p: p value

Table 3.
Mean scores on the five domains of the K-BRIAN
Domains Control subjects BD I BD II
Sleep 9.28±2.64 10.45±4.19 12.89±4.27
Activity 7.17±2.36 9.48±4.17 11.43±4.47
Social rhythms 5.65±1.92 7.10±2.62 8.56±3.32
Eating pattern 7.05±2.59 7.82±2.92 10.10±3.55
Predominant rhythm 5.88±1.45 6.34±1.44 7.20±1.72

Values are presented in mean±standard deviations. K-BRIAN: Korean version of the biological rhythms interview of assessment in neuropsychiatry, BD: bipolar disorder

Table 4.
Reliability analysis of the K-BRIAN
Item number Scale mean if item deleted Corrected item to total correlation Cronbach’s alpha if item deleted
1 41.53 0.609 0.909
2 41.47 0.602 0.909
3 41.37 0.584 0.909
4 41.58 0.613 0.909
5 41.53 0.659 0.908
6 41.65 0.603 0.909
7 41.82 0.669 0.907
8 41.65 0.761 0.905
9 41.62 0.754 0.905
10 42.16 0.534 0.911
11 41.71 0.653 0.908
12 42.17 0.443 0.912
13 41.81 0.601 0.909
14 41.89 0.629 0.909
15 41.42 0.701 0.906
16 41.48 0.497 0.911
17 41.44 0.630 0.908
18 41.99 0.403 0.913
19 41.31 0.436 0.913
20 41.67 0.301 0.926
21 41.65 0.466 0.912
Total 0.914

K-BRIAN: Korean version of the biological rhythms interview of assessment in neuropsychiatry


1. Giglio LM, Magalhaes PV, Andreazza AC, Walz JC, Jakobson L, Rucci P, et al. Development and use of a biological rhythm interview. J Affect Disord 2009;118:161-165.
crossref pmid
2. Rumble ME, White KH, Benca RM. Sleep disturbances in mood disorders. Psychiatr Clin North Am 2015;38:743-759.
crossref pmid
3. Moon JH, Cho CH, Son GH, Geum D, Chung S, Kim H, et al. Advanced circadian phase in mania and delayed circadian phase in mixed mania and depression returned to normal after treatment of bipolar disorder. EBiomedicine 2016;11:285-295.
crossref pmid pmc
4. Moro MF, Carta MG, Pintus M, Pintus E, Melis R, Kapczinski F, et al. Validation of the Italian Version of the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN): some considerations on its screening usefulness. Clin Pract Epidemiol Ment Health 2014;10:48-52.
crossref pmid pmc
5. Giglio LM, Magalhães PV, Kapczinski NS, Walz JC, Kapczinski F. Functional impact of biological rhythm disturbance in bipolar disorder. J Psychiatr Res 2010;44:220-223.
crossref pmid
6. Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health-related quality of life measures: literature review and proposed guidelines. J Clin Epidemiol 1993;46:1417-1432.
crossref pmid
7. Kasper S, Wehr TA. The role of sleep and wakefulness in the genesis of depression and mania. Encéphale 1992;18:45-50.

8. Ahn YM, Chang J, Joo YH, Kim SC, Lee KY, Kim YS. Chronotype distribution in bipolar I disorder and schizophrenia in a Korean sample. Bipolar Disord 2008;10:271-275.
crossref pmid
9. Vadnie CA, McClung CA. Circadian rhythm disturbances in mood disorders: insights into the role of the suprachiasmatic nucleus. Neural Plast 2017;2017:1-28.
crossref pdf
10. Robillard R, Naismith SL, Hickie IB. Recent advances in sleep-wake cycle and biological rhythms in bipolar disorder. Curr Psychiatry Rep 2013;15:402.
crossref pmid
11. Zee PC, Attarian H, Videnovic A. Circadian rhythm abnormalities. Continuum Lifelong Learn Neurol 2013;19:132-147.
12. Cho CH, Moon JH, Yoon HK, Kang SG, Geum D, Son GH, et al. Molecular circadian rhythm shift due to bright light exposure before bedtime is related to subthreshold bipolarity. Sci Rep 2016;6:31846.
crossref pmid pmc pdf
13. Seleem MA, Merranko JA, Goldstein TR, Goldstein BI, Axelson DA, Brent DA, et al. The longitudinal course of sleep timing and circadian preferences in adults with bipolar disorder. Bipolar Disord 2015;17:392-402.
crossref pmid
14. Frank E, Hlastala S, Ritenour A, Houck P, Tu XM, Monk TH, et al. Inducing lifestyle regularity in recovering bipolar disorder patients: results from the maintenance therapies in bipolar disorder protocol. Biol Psychiatry 1997;41:1165-1173.
crossref pmid
15. Leibenluft E, Suppes T. Treating bipolar illness: focus on treatment algorithms and management of the sleep-wake cycle. Am J Psychiatry 1999;156:1976-1981.
16. Pail G, Huf W, Pjrek E, Winkler D, Willeit M, Praschak-Rieder N, et al. Bright-light therapy in the treatment of mood disorders. Neuropsychobiology 2011;64:152-162.
crossref pmid
17. Padiath QS, Paranjpe D, Jain S, Sharma VK. Glycogen synthase kinase 3β as a likely target for the action of lithium on circadian clocks. Chronobiol Int 2004;21:43-55.
crossref pmid
18. Li X, Bijur GN, Jope RS. Glycogen synthase kinase-3β, mood stabilizers, and neuroprotection. Bipolar Disord 2002;4:137-144.
crossref pmid pmc
19. Rosenthal N, Bradt G, Wehr T. Seasonal Pattern Assessment Questionnaire. Bethesda: National Institute of Mental Health; 1987.

20. Horne JA, Ostberg O. A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. Int J Chronobiol 1976;4:97-110.
21. Bradley AJ, Webb-Mitchell R, Hazu A, Slater N, Middleton B, Gallagher P, et al. Sleep and circadian rhythm disturbance in bipolar disorder. Psychol Med 2017;47:1678-1689.
crossref pmid
22. Wood J, Birmaher B, Axelson D, Ehmann M, Kalas C, Monk K, et al. Replicable differences in preferred circadian phase between bipolar disorder patients and control individuals. Psychiatry Res 2009;166:201-209.
crossref pmid pmc
23. Bullock B, Corlass-Brown J, Murray G. Eveningness and seasonality are associated with the bipolar disorder vulnerability trait. J Psychopathol Behav Asess 2014;36:443-451.
24. Association AP. Diagnostic and Statistical Manual of Mental Disorders (DSM-5®). Washington DC: American Psychiatric Pub; 2013.

25. Cho CH, Ahn YM, Kim SJ, Ha TH, Jeon HJ, Cha B, et al. Design and methods of the Mood Disorder Cohort Research Consortium (MDCRC) Study. Psychiatry Investig 2017;14:100-106.
crossref pmid
26. Hergueta T, Baker R, Dunbar GC. The Mini-International Neuropsychiatric Interview (MINI): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry 1998;59(Suppl 20):22-33.

27. Pinho M, Sehmbi M, Cudney L, Kauer-Sant’anna M, Magalhães P, Reinares M, et al. The association between biological rhythms, depression, and functioning in bipolar disorder: a large multi-center study. Acta Psychiatr Scand 2016;133:102-108.
crossref pmid
28. Rosa AR, Comes M, Torrent C, Solè B, Reinares M, Pachiarotti I, et al. Biological rhythm disturbance in remitted bipolar patients. Int J Bipolar Disord 2013;1:6.
crossref pmid pmc
29. Allega OR, Leng X, Vaccarino A, Skelly M, Lanzini M, Hidalgo MP, et al. Performance of the biological rhythms interview for assessment in neuropsychiatry: an item response theory and actigraphy analysis. J Affect Disord 2018;225:54-63.
crossref pmid
30. Chung JK, Lee KY, Kim SH, Kim EJ, Jeong SH, Jung HY, et al. Circadian rhythm characteristics in mood disorders: comparison among bipolar I disorder, bipolar II disorder and recurrent major depressive disorder. Clin Psychopharmacol Neurosci 2012;10:110-116.
crossref pmid pmc
31. Refinetti R, Menaker M. The circadian rhythm of body temperature. Physiol Behav 1992;51:613-637.
crossref pmid
32. Son GH, Chung S, Choe HK, Kim HD, Baik SM, Lee H, et al. Adrenal peripheral clock controls the autonomous circadian rhythm of glucocorticoid by causing rhythmic steroid production. Proc Natl Acad Sci USA 2008;105:20970-20975.
crossref pmid
33. Inouye SI, Kawamura H. Persistence of circadian rhythmicity in a mammalian hypothalamic “island” containing the suprachiasmatic nucleus. Proc Natl Acad Sci USA 1979;76:5962-5966.
crossref pmid
34. Lee HA, Lee HJ, Moon JH, Lee T, Kim MG, In H, et al. Comparison of wearable activity tracker with actigraphy for sleep evaluation and circadian rest-activity rhythm measurement in healthy young adults. Psychiatry Investig 2017;14:179-185.
crossref pmid pmc
35. Morgenthaler T, Alessi C, Friedman L, Owens J, Kapur V, Boehlecke B, et al. Practice parameters for the use of actigraphy in the assessment of sleep and sleep disorders: an update for 2007. Sleep 2007;30:519-529.
crossref pmid pdf
36. Van de Mortel TF. Faking it: social desirability response bias in self-report research. Aust J Adv Nurs 2008;25:40-48.

37. Wherry Sr RJ, Bartlett C. The control of bias in ratings: a theory of rating. Pers Psychol 1982;35:521-551.
38. Lee HS, Kang CM, Kang BW, Kim HK. Seasonal variations of acidic air pollutants in Seoul, South Korea. Atmos Environ 1999;33:3143-3152.
39. Cho CH, Lee HJ, Yoon HK, Kang SG, Bok KN, Jung KY, et al. Exposure to dim artificial light at night increases REM sleep and awakenings in humans. Chronobiol Int 2016;33:117-123.
crossref pmid
40. Johansson C, Willeit M, Smedh C, Ekholm J, Paunio T, Kieseppä T, et al. Circadian clock-related polymorphisms in seasonal affective disorder and their relevance to diurnal preference. Neuropsychopharmacology 2003;28:734-739.
crossref pmid pdf
41. Lee HJ, Rex KM, Nievergelt CM, Kelsoe JR, Kripke DF. Delayed sleep phase syndrome is related to seasonal affective disorder. J Affect Disord 2011;133:573-579.
crossref pmid pmc
42. Murray G, Allen NB, Trinder J. Seasonality and circadian phase delay: prospective evidence that winter lowering of mood is associated with a shift towards Eveningness. J Affect Disord 2003;76:15-22.
crossref pmid


Browse all articles >

Editorial Office
#522, 27, Seochojungang-ro 24-gil, Seocho-gu, Seoul 06601, Korea
Tel: +82-2-537-6171    Fax: +82-2-537-6174    E-mail:                

Copyright © 2019 by Korean Neuropsychiatric Association. All rights reserved.

Developed in M2community

Close layer
prev next