How do stress, sleep quality, and chronotype associate with clinically significant depressive symptoms? A study of young male military recruits in compulsory service

Objective: Although studies have shown an association between poor sleep and chronotype with psychiatric problems in young adults, few have focused on identifying multiple concomitant risk factors. Methods: We assessed depressive symptoms (Beck Depression Inventory [BDI]), circadian typology (Morningness-Eveningness Questionnaire [MEQ]), sleep quality (Pittsburgh Sleep Quality Index [PSQI]), perceived stress (Perceived Stress Scale [PSS]), social rhythm (Social Rhythm Metrics [SRM]), and salivary cortisol (morning, evening and night, n=37) in 236 men (all 18 years old). Separate analyses were conducted to understand how each PSQI domain was associated with depressive symptoms. Results: Depressive symptoms were more prevalent in individuals with higher perceived stress (prevalence ratio [PR] = 6.429, p < 0.001), evening types (PR = 2.58, p < 0.001) and poor sleepers (PR = 1.808, p = 0.046). Multivariate modeling showed that these three variables were independently associated with depressive symptoms (all p < 0.05). The PSQI items subjective sleep quality and sleep disturbances were significantly more prevalent in individuals with depressive symptoms (PR = 2.210, p = 0.009 and PR = 2.198, p = 0.008). Lower levels of morning cortisol were significantly associated with higher depressive scores (r = -0.335; p = 0.043). Conclusion: It is important to evaluate multiple factors related to sleep and chronotype in youth depression studies, since this can provide important tools for comprehending and managing mental health problems.

Assessment and Understanding of Chronotype / 수면정신생리

Chronotype (CT) is defined as an inter-individual difference in sleep-wake cycles and daily activities. Previous studies have suggested that this individual difference can influence our biological and psychological functioning. Literature regarding the psychometric properties and validity of CT measures are reviewed. We provide an overview of biological indicators (sleep-wake cycle, body temperature, cortisol, and melatonin) that are used for distinguishing two chronotypes: morningness (MT) and eveningness (ET). We also review the differences between CT in relation to personality traits and the occurrence of psychopathology. In addition, the methodological limitations of studies on CT are discussed. Finally, future research directions in terms of CT are proposed.

Relationship between circadian typology and internet addiction in college students / 中华行为医学与脑科学杂志

Objective To investigate status of internet addiction and circadian typology in college students and to explore the relationship between circadian typology and internet addiction. Methods A total of 3 572 college students including freshmen and juniors was enrolled in the study. Circadian typology and internet addiction were assessed by morningness-eveningness questionnaire(MEQ) and internet addiction test (IAT) respectively. All questionnaires were self-reported. Results The score of IAT was (38. 46±11. 84) points and incidence of internet addiction was 41. 7%. Freshmen and juniors were significantly different in distribution of circadian typology and IAT scores(χ2=10. 51,P<0. 05; t=5. 90,P<0. 01). Proportion of the evening type and scores of IAT of juniors(33. 0%,(39. 66±12. 71)points) were both higher than those of freshmen(28. 3%,(37. 32±10. 82)points). For freshmen,IAT scores of evening type students((40. 79± 11. 33)points) was higher than those of intermediate type students((36. 54±10. 27)points) and morning type students((32. 27±9. 66)points),and the differences were statistically significant(F=51. 81,P<0. 01). For juniors,IAT scores of evening type students((42. 90±13. 02)points) was higher than those of intermedi-ate type students((38. 61±12. 19)points) and morning type students((34. 06±11. 92)points),and the differences were statistically significant(F=37. 80,P<0. 01). After adjusting for gender,age,grade and par-ents’ educational level by analysis of covariance,IAT scores were still statistically different in circadian ty-pology(F=93. 53,P<0. 01). Results from ordinal logistic regression showed that grade(juniors compared to freshman,OR=1. 42,P<0. 01) and circadian typology (evening type compared to morning type,OR=3. 82,P<0. 01; intermediate type compared to morning type,OR=1. 97,P<0. 01) were independent factors influen- cing internet addiction. Conclusion Internet addiction of college students is at a high level and different in grades. Compared with junior students,senior students are at a higher level of internet addiction. College students with evening type are more likely to be internet addicted.

The effects of circadian typology on glycemic control in patients with type 2 diabetes / 中国实用护理杂志

Objective To investigate the distribution of circadian typology of patients with type 2 diabetes mellitus (T2DM) and to analyze its consequent impact on glycemic control. Methods From January 2016 to June 2016, a total of 283 T2DM patients were interviewed in this study. Self designed questionnaire, Morningness-Eveningness Questionnaire (MEQ), Pittsburg Sleep Quality Index (PSQI) and Center for Epidemiological Survey-Depression Scale (CES-D) were used to collect information on diabetes history, circadian typology, sleep quality and depression. HbA1c and other biochemical indicators were determined. The glycemic control target was<7%. The 283 T2DM patients were divided into three groups:morning type group, evening type group and neither type group according to MEQ score. Results Of the 283 subjects, 97 (34.3%) were classified as morning type, 42 (14.8%) as evening type, and 144 (50.9%) as neither. Participants with evening type were younger, shorter diabetes duration, more depressive symptoms, higher perceived sleep debt, higher FBG and higher HbA1c than those with morning type. The binary Logistic regression analysis showed that HbAlc≥7%was associated with higher FBG, higher PSQI score, higher sleep debt, lower HDL-C, and lower MEQ scores (OR=0.189-2.904, all P<0.05). Conclusions Evening type was associated with higher HbA1c and poorer glycemic control in T2DM patients compared with morning type and may be one of the risk factors affecting glycemic control.

The effects of circadian typology on glycemic control in patients with type 2 diabetes / 中国实用护理杂志

Objective To investigate the distribution of circadian typology of patients with type 2 diabetes mellitus (T2DM) and to analyze its consequent impact on glycemic control. Methods From January 2016 to June 2016, a total of 283 T2DM patients were interviewed in this study. Self designed questionnaire, Morningness-Eveningness Questionnaire (MEQ), Pittsburg Sleep Quality Index (PSQI) and Center for Epidemiological Survey-Depression Scale (CES-D) were used to collect information on diabetes history, circadian typology, sleep quality and depression. HbA1c and other biochemical indicators were determined. The glycemic control target was<7%. The 283 T2DM patients were divided into three groups:morning type group, evening type group and neither type group according to MEQ score. Results Of the 283 subjects, 97 (34.3%) were classified as morning type, 42 (14.8%) as evening type, and 144 (50.9%) as neither. Participants with evening type were younger, shorter diabetes duration, more depressive symptoms, higher perceived sleep debt, higher FBG and higher HbA1c than those with morning type. The binary Logistic regression analysis showed that HbAlc≥7%was associated with higher FBG, higher PSQI score, higher sleep debt, lower HDL-C, and lower MEQ scores (OR=0.189-2.904, all P<0.05). Conclusions Evening type was associated with higher HbA1c and poorer glycemic control in T2DM patients compared with morning type and may be one of the risk factors affecting glycemic control.

The Effect of Circadian Types and Depressive Mood on Internet Addiction in Korean College Students

OBJECTIVES: The purpose of this study was to investigate the relationships among circadian types, depressive mood and internet addiction and to identify the mediating effect of depressive mood between circadian types and internet addiction in Korean College Students. METHODS: A total of 2632 participants completed questionnaires, which included the Korean translation of the Composite Scale of Morningness (CSM), the Patient Health Questionnaire (PHQ-9), and the Korean version of the Internet Addiction Test (KIAT). Statistical analyses were done using correlation analysis, analysis of covariance and multiple linear regression. RESULTS: The CSM score was negatively associated with the PHQ-9 score (r = -0.226, p < 0.001) and the KIAT score (r = -0.218, p < 0.001). The eveningness group showed higher scores in depressive mood and internet addiction than the morningness group (p < 0.001). Depressive mood showed a partial mediating effect between circadian types and internet addiction (β = 0.255, p < 0.001). CONCLUSIONS: Internet addiction was associated with circadian types and depressive mood. These results suggest that depression and circadian rhythm management would contribute to the prevention of internet addiction.

Life Satisfaction and Bipolarity according to Circadian Typology

OBJECTIVES: The purpose of this study was to investigate the relationships among circadian typology, bipolarity and life satisfaction of university students. METHODS: A total 1232 participants completed questionnaires, which included Composite Scale of Morningness (CSM), Satisfaction with Life Scale (SWLS), and Mood Disorder Questionnaire (MDQ). Statistical analyses were done using correlation analysis, and analysis of covariance. RESULTS: The CSM score was positively associated with SWLS score (r = 0.232 ; p < 0.001). The morningness group has higher life satisfaction than the eveningness group (p < 0.001). The eveningness group has higher bipolarity than the morningness group (p < 0.001). The CSM score was negatively associated with MDQ score (r = -0.128 ; p < 0.001). CONCLUSIONS: Bipolarity and life satisfaction were associated with circadian typology. Morningness was the important determinant of life satisfaction and bipolarity.