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Chronobiol Med > Volume 5(4); 2023 > Article
Lee: Emotional Dysregulation in Shift Workers


Shift work continues to increase in frequency in industrial society and accounts for more than 20% of workers in modern society. Previous studies have reported that shift work is a representative environmental factor that disrupts circadian rhythm and is associated with various physical and mental problems, including sleep problems. In particular, problems with circadian rhythm are closely related to difficulties in emotional regulation that cause mood disorders. In this review, we reviewed previous studies on emotion dysregulation in shift workers and examined past studies on the neuroscience basis for these problems. If neurobiological research yields results on shift workers’ vulnerability to emotional and sleep problems, it would be possible to suggest ways to prevent the adverse mental effects of shift work.


In today’s society, more than 20% of workers engage in shift work. Shift work is defined by non-standard working hours (e.g., any time other than from 7:00 AM to 6:00 PM) that are often misaligned with natural circadian rhythms [1]. Shift work is necessary for various sectors, including 24-hour healthcare, transportation, and protective services [2]. Due to the heightened demands of modern society, shift work has become more prevalent [3,4]; this prevalence may increase the risks of mental and physical health problems among workers. Indeed, there is evidence that circadian rhythm disruption is associated with various mental and physical diseases, including sleep disorders, gastrointestinal disorders, metabolic disorders, neoplasms, immune diseases, and mood disorders such as depression [5]. In addition to emotional disturbances such as anxiety/depression, shift work-induced circadian rhythm disruption can lead to cognitive abnormalities such as poor concentration/memory [5].
Other adverse effects of shift work include daytime sleepiness, fatigue, decreased work efficiency, and accidents; approximately 25% of shift workers meet the diagnostic criteria for a circadian rhythm disorder [6].


As previously noted, shift work is a risk factor for various health problems, such as sleep–wake disorders and mood problems (e.g., depressed mood and anxiety) [1]. Shift workers often experience sleep disturbance and circadian disruption [7,8]. Shift work can result in desynchronization between homeostatic sleep pressure and circadian rhythmicity, leading to an increased risk of sleep disturbance [9]. Previous studies have shown that the uncoupling of homeostatic pressure and circadian alert signals increases vulnerability to sleep disturbance among shift workers [10].
Sleep disturbance after a circadian challenge increases the risk of “sleep work disorder” (SWD) and depressive mood in shift workers [11]. Additionally, major depressive disorders are more prevalent among shift workers [12]. Previous studies have revealed that 8.1%–43.0% of shift workers meet the criteria for SWD, which is defined as difficulty sleeping when sleep is appropriate and/or excessive sleepiness during the waking period [6,13]. It has been suggested that sleep disorders among shift workers occur only when shift work affects specific brain regions [11]. However, the mechanisms through which shift work-induced circadian rhythm disruption leads to cognitive and emotional abnormalities via changes in brain activity remain unclear.


The relationship between sleep disorders and bipolar disorder is well-known, and the risk of bipolar disorder increases with the degree of circadian rhythm fluctuation and sleep deprivation [14]. In addition, a recent meta-analysis showed that shift workers have a 1.33-fold higher risk of depression compared with daytime workers [1].
Circadian rhythm disorders and sleep disorders are associated with depression; chronotherapy, which corrects circadian rhythms through light therapy, sleep deprivation, and adjustment of social rhythms, serves as a major supplemental treatment for depression [15]. The genetic and molecular mechanisms through which circadian rhythm disruptions cause brain dysfunction, including cognitive decline and emotional disorders, have not been fully determined.


Emotional dysregulation, which is associated with sleep disturbance and circadian disruption, constitutes a common feature of mood disorders [16,17]. Healthy volunteers and patients who experience disrupted sleep and circadian rhythms often report emotional dysregulation, including heightened emotional reactivity to negative events and difficulty regulating negative emotions [10,18,19].
Considering that shift workers report sleep disturbance and circadian disruption [7,8], along with vulnerability to mood problems [7,20,21], shift work may be a risk factor for emotional dysregulation. Additionally, the disruption of sleep–wake cycles is associated with negative emotions and delayed recovery from negative events [18,22]. Therefore, the ability to regulate emotions may be undermined by shift work.
The findings in previous studies suggest that emotional regulation can modulate the effects of emotional stress on sleep. When sleep disturbance and impaired emotional regulation coexist, emotional arousal tends to be greater and sleep difficulties are more likely, contributing to the development of depression [23]. Moreover, in combination with sleep disturbance, enhanced sensitivity and reactivity to sleep-related stimuli can exacerbate depressive symptoms [24]. However, few studies have examined emotional dysregulation in shift workers.
Emotional regulation has been correlated with neural activity in subcortical limbic (e.g., amygdala and insula) and prefrontal (e.g., lateral prefrontal cortex [PFC] and medial PFC) regions [25-27]. Shift workers may show neural alterations in regions implicated in emotional reactivity and regulation. Disrupted sleep and circadian rhythms, which are problematic for shift workers, have been associated with neural alterations in such regions [16,17]. For example, sleep disturbance increases neural activation in response to negative stimuli in the amygdala [28], but it is associated with reduced activity in the dorsomedial PFC and dorsal anterior cingulate cortex (ACC) during emotional regulation [29,30]. Additionally, mood problems, regarded as adverse consequences of shift work, appear to involve changes in brain regions implicated in emotional dysregulation [31-33].
At the molecular level, McClung [34] proposed that the relationship between disrupted circadian rhythms and emotional dysregulation was mediated by the effects of the molecular clock on major neurotransmitters implicated in mood regulation, such as serotonin, norepinephrine, and dopamine. The underlying mechanism remains unclear, although projections from the suprachiasmatic nucleus (SCN) to other brain regions implicated in the regulation of monoaminergic neuronal activity, such as the locus coeruleus, may play a role [34,35]. Additionally, the expression of circadian genes outside of the SCN (e.g., in the PFC) may contribute to emotional regulation through the rhythmic activity of monoamine neurotransmitters. Otsuka et al. [36] reported that circadian misalignment disrupted the expression patterns of clock and immediate early genes in the PFC, resulting in depression-like behaviors in rats. Considering that clock genes control the dopaminergic system and that PFC activity is associated with mood regulation, the PFC may mediate the relationship between clock function and mood regulation.
On the basis of the above studies, it is important to identify risk factors for circadian misalignment among shift workers, as well as risk factors for progression from sleep disturbance to depression.


Few brain imaging studies of shift workers have been conducted, partially because of the difficulties imposed by the heterogeneity and relatively small size of the study population. Nevertheless, a functional magnetic resonance imaging (fMRI) study revealed greater neural activity in the left dorsolateral PFC among rotating shift workers compared with controls during an emotional Stroop task that involved negative emotional words [37]. In that study, sleep disturbance was more strongly associated with depressive symptoms when left dorsolateral PFC activity was high. The left dorsolateral PFC may also play an important role in sensitivity to emotional information.
Cerebral perfusion was reportedly reduced in the cuneus, fusiform/parahippocampal gyri, and cerebellum of the right hemisphere in shift workers, whereas it was increased in the inferior occipital gyrus of the left hemisphere. Moreover, changes in perfusion were associated with depression and insomnia [38].
Regarding white matter integrity, shift workers exhibited higher fractional anisotropy (FA) values in the bilateral anterior cingulum compared with non-shift workers; increased FA in the right anterior cingulum was correlated with poor sleep quality [39]. A resting-state fMRI study showed that shift workers exhibited altered functional connectivity in the salience network. In particular, they displayed reduced resting-state functional connectivity (rsFC) between the ACC and right insula, as well as increased rsFC of the ACC with the left occipital lobe and right superior frontal gyrus extending to the supplementary motor area [40].


Shift work, which is common in industrial societies, has been associated with various sleep and psychiatric disorders. However, few studies have explored the biological mechanisms underlying circadian misalignment among shift workers. The adverse effects of shift work are diverse and extensive. Historically, shift work research has focused on the direct consequences of circadian misalignment for sleep and sleepiness, but emerging research is highlighting the potential for emotional dysregulation. Future studies should explore the neurobiological basis of interindividual differences in the effects of shift work, as well as methods to promote resilience to its adverse psychological and biological consequences.


Funding Statement

This research was supported by the Technology Innovation Infrastructure program through the Korea Institute for Advancement of Technology funded by the Ministry of Trade, Industry and Energy (study no.: P0014279).

Conflicts of Interest

Yu Jin Lee, a contributing editor of Chronobiology in Medicine, was not involved in the editorial evaluation or decision to publish this article.

Availability of Data and Material

Data sharing not applicable to this article as no datasets were generated or analyzed during the study.


1. Torquati L, Mielke GI, Brown WJ, Burton NW, Kolbe-Alexander TL. Shift work and poor mental health: a meta-analysis of longitudinal studies. Am J Public Health 2019;109:e13–e20.
crossref pmid pmc
2. Brown JP, Martin D, Nagaria Z, Verceles AC, Jobe SL, Wickwire EM. Mental health consequences of shift work: an updated review. Curr Psychiatry Rep 2020;22:7.
crossref pmid pdf
3. Cheng P, Drake CL. Psychological impact of shift work. Curr Sleep Med Rep 2018;4:104–109.
crossref pmid pmc pdf
4. Wright KP Jr, Bogan RK, Wyatt JK. Shift work and the assessment and management of shift work disorder (SWD). Sleep Med Rev 2013;17:41–54.
crossref pmid
5. Bass J, Lazar MA. Circadian time signatures of fitness and disease. Science 2016;354:994–999.
crossref pmid
6. Drake CL, Roehrs T, Richardson G, Walsh JK, Roth T. Shift work sleep disorder: prevalence and consequences beyond that of symptomatic day workers. Sleep 2004;27:1453–1462.
crossref pmid
7. James SM, Honn KA, Gaddameedhi S, Van Dongen HPA. Shift work: disrupted circadian rhythms and sleep-implications for health and well-being. Curr Sleep Med Rep 2017;3:104–112.
crossref pmid pmc pdf
8. Kervezee L, Kosmadopoulos A, Boivin DB. Metabolic and cardiovascular consequences of shift work: the role of circadian disruption and sleep disturbances. Eur J Neurosci 2020;51:396–412.
crossref pmid pdf
9. Khan WAA, Conduit R, Kennedy GA, Jackson ML. The relationship between shift-work, sleep, and mental health among paramedics in Australia. Sleep Health 2020;6:330–337.
crossref pmid
10. Wickwire EM, Geiger-Brown J, Scharf SM, Drake CL. Shift work and shift work sleep disorder: clinical and organizational perspectives. Chest 2017;151:1156–1172.
crossref pmid
11. Kalmbach DA, Pillai V, Cheng P, Arnedt JT, Drake CL. Shift work disorder, depression, and anxiety in the transition to rotating shifts: the role of sleep reactivity. Sleep Med 2015;16:1532–1538.
crossref pmid pmc
12. Ohayon MM, Hong SC. Prevalence of major depressive disorder in the general population of South Korea. J Psychiatr Res 2006;40:30–36.
crossref pmid
13. Barger LK, Ogeil RP, Drake CL, O’Brien CS, Ng KT, Rajaratnam SMW. Validation of a questionnaire to screen for shift work disorder. Sleep 2012;35:1693–1703.
crossref pmid pmc
14. Harvey AG. Sleep and circadian rhythms in bipolar disorder: seeking synchrony, harmony, and regulation. Am J Psychiatry 2008;165:820–829.
crossref pmid
15. Germain A, Kupfer DJ. Circadian rhythm disturbances in depression. Hum Psychopharmacol 2008;23:571–585.
crossref pmid pmc
16. Chellappa SL. Circadian misalignment: a biological basis for mood vulnerability in shift work. Eur J Neurosci 2020;52:3846–3850.
crossref pmid pdf
17. Gruber R, Cassoff J. The interplay between sleep and emotion regulation: conceptual framework empirical evidence and future directions. Curr Psychiatry Rep 2014;16:500.
crossref pmid pdf
18. O’Leary K, Small BJ, Panaite V, Bylsma LM, Rottenberg J. Sleep quality in healthy and mood-disordered persons predicts daily life emotional reactivity. Cogn Emot 2017;31:435–443.
crossref pmid pmc
19. O’Leary K, Bylsma LM, Rottenberg J. Why might poor sleep quality lead to depression? A role for emotion regulation. Cogn Emot 2017;31:1698–1706.
crossref pmid pmc
20. Jagannath A, Peirson SN, Foster RG. Sleep and circadian rhythm disruption in neuropsychiatric illness. Curr Opin Neurobiol 2013;23:888–894.
crossref pmid
21. Jones SG, Benca RM. Circadian disruption in psychiatric disorders. Sleep Med Clin 2015;10:481–493.
crossref pmid
22. Bower B, Bylsma LM, Morris BH, Rottenberg J. Poor reported sleep quality predicts low positive affect in daily life among healthy and mood-disordered persons. J Sleep Res 2010;19:323–332.
crossref pmid
23. Vandekerckhove M, Wang YL. Emotion, emotion regulation and sleep: an intimate relationship. AIMS Neurosci 2017;5:1–17.
crossref pmid pmc
24. Nakajima S, Komada Y, Sasai-Sakuma T, Okajima I, Harada Y, Watanabe K, et al. Higher sleep reactivity and insomnia mutually aggravate depressive symptoms: a cross-sectional epidemiological study in Japan. Sleep Med 2017;33:130–133.
crossref pmid
25. Buhle JT, Silvers JA, Wager TD, Lopez R, Onyemekwu C, Kober H, et al. Cognitive reappraisal of emotion: a meta-analysis of human neuroimaging studies. Cereb Cortex 2014;24:2981–2990.
crossref pmid pmc
26. Lindquist KA, Satpute AB, Wager TD, Weber J, Barrett LF. The brain basis of positive and negative affect: evidence from a meta-analysis of the human neuroimaging literature. Cereb Cortex 2016;26:1910–1922.
crossref pmid pmc
27. Morawetz C, Riedel MC, Salo T, Berboth S, Eickhoff SB, Laird AR, et al. Multiple large-scale neural networks underlying emotion regulation. Neurosci Biobehav Rev 2020;116:382–395.
crossref pmid
28. Yoo SS, Gujar N, Hu P, Jolesz FA, Walker MP. The human emotional brain without sleep--a prefrontal amygdala disconnect. Curr Biol 2007;17:R877–R878.
crossref pmid
29. Klumpp H, Roberts J, Kapella MC, Kennedy AE, Kumar A, Phan KL. Subjective and objective sleep quality modulate emotion regulatory brain function in anxiety and depression. Depress Anxiety 2017;34:651–660.
crossref pmid pmc pdf
30. Minkel JD, McNealy K, Gianaros PJ, Drabant EM, Gross JJ, Manuck SB, et al. Sleep quality and neural circuit function supporting emotion regulation. Biol Mood Anxiety Disord 2012;2:22.
crossref pmid pmc pdf
31. Diener C, Kuehner C, Brusniak W, Ubl B, Wessa M, Flor H. A meta-analysis of neurofunctional imaging studies of emotion and cognition in major depression. Neuroimage 2012;61:677–685.
crossref pmid
32. Kolesar TA, Bilevicius E, Wilson AD, Kornelsen J. Systematic review and meta-analyses of neural structural and functional differences in generalized anxiety disorder and healthy controls using magnetic resonance imaging. Neuroimage Clin 2019;24:102016.
crossref pmid pmc
33. Rive MM, van Rooijen G, Veltman DJ, Phillips ML, Schene AH, Ruhé HG. Neural correlates of dysfunctional emotion regulation in major depressive disorder. A systematic review of neuroimaging studies. Neurosci Biobehav Rev 2013;37(10 Pt 2): 2529–2553.

34. McClung CA. Circadian genes, rhythms and the biology of mood disorders. Pharmacol Ther 2007;114:222–232.
crossref pmid pmc
35. Aston-Jones G, Chen S, Zhu Y, Oshinsky ML. A neural circuit for circadian regulation of arousal. Nat Neurosci 2001;4:732–738.
crossref pmid pdf
36. Otsuka T, Thi Le H, Kohsaka A, Sato F, Ihara H, Nakao T, et al. Adverse effects of circadian disorganization on mood and molecular rhythms in the prefrontal cortex of mice. Neuroscience 2020;432:44–54.
crossref pmid
37. Kim SY, Lee KH, Lee H, Jeon JE, Kim S, Lee MH, et al. Neural activation underlying emotional interference of cognitive control in rotating shift workers: moderating effects of the prefrontal cortex response on the association between sleep disturbance and depressive symptoms. Sleep 2022;45:zsac219.
crossref pmid pdf
38. Park YK, Kim JH, Choi SJ, Kim ST, Joo EY. Altered regional cerebral blood flow associated with mood and sleep in shift workers: cerebral perfusion magnetic resonance imaging study. J Clin Neurol 2019;15:438–447.
crossref pmid pmc pdf
39. Lee J, Kim M, Kim N, Hwang Y, Lee KH, Lee J, et al. Evidence of white matter integrity changes in the anterior cingulum among shift workers: a crosssectional study. Nat Sci Sleep 2022;14:1417–1425.
crossref pmid pmc pdf
40. Kim SY, Lee KH, Lee HY, Jeon JE, Park CW, Shin J, et al. Circadian misalignment alters resting-state functional connectivity of the salience network in rotating shift workers. Sleep 2023;46:zsad237.
crossref pmid pdf
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