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Circadian preference links to depression in general adult population
Journal of Affective Disorders 188 (2015) 143–148
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Journal of Affective Disorders journal homepage: www.elsevier.com/locate/jad
Research report
Circadian preference links to depression in general adult population Ilona Merikanto a,b,c,n, Erkki Kronholm d, Markku Peltonen a, Tiina Laatikainen a,e,f, Erkki Vartiainen a, Timo Partonen a a
Department of Health, National Institute for Health and Welfare, FI-00271 Helsinki, Finland Department of Biosciences, University of Helsinki, Helsinki, Finland c Orton Orthopaedics Hospital, Helsinki, Finland d Department of Health, National Institute for Health and Welfare, Turku, Finland e Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland f Hospital District of North Karelia, Joensuu, Finland b
art ic l e i nf o
a b s t r a c t
Article history: Received 2 June 2015 Received in revised form 31 July 2015 Accepted 26 August 2015 Available online 1 September 2015
Background: Preference to time the daily activities towards the evening hours has been associated with a greater likelihood for depression in earlier studies consisting of relatively small samples. Methods: In the current study, we analyzed the relationship between chronotype and depression using a combined population-based sample of 10,503 Finnish adults aged 25 to 74 years from the two national FINRISK 2007 and 2012 health examination studies. Results: Our results confirmed that eveningness was significantly associated with the increased odds for a diagnosed depressive disorder, antidepressant medication, and depressive symptoms (p o0.0001 for each), after controlling for a range of depression-attributed and potential confounding factors. Regardless of depressive symptoms, Evening-types had lower systolic and diastolic blood pressures, a smaller waist circumference, and a lower body weight than other chronotypes. Limitations: A limitation to our study is that the assessment of chronotype and information about depression was based on the self-report information only. However, the big population-based sample, which is derived from a national health examination survey, is a major strength of our study. Conclusions: In conclusion, our study is in line the results from the previous, smaller sample size studies confirming that Evening-types have higher risk for depression than other chronotypes. This risk is elevated even among those Evening-types with sufficient amount of sleep. & 2015 Elsevier B.V. All rights reserved.
Keywords: Alcohol Body-mass index Chronobiology Diurnal Morningness Sleep
1. Introduction Earlier studies have demonstrated that individuals with the tendency towards eveningness in their preference to time the daily activities (Evening-types) bear a greater likelihood for depressive symptoms or major depression than those with the tendency being towards morningness (Drennan et al., 1991; Chelminski et al., 1999; Gaspar-Barba et al.,, 2009; Hidalgo et al.,, 2009; Antunes et al., 2010; Hasler et al., 2010; Kim et al., 2010; Kitamura et al., 2010; Selvi et al., 2010; Abe et al., 2011; Levandovski et al., 2011; Meliska et al., 2011; Merikanto et al., 2013a; Chan et al., 2014). Evening-types also seem to have greater odds for stressrelated eating and for suicide (Bahk et al., 2014; Chan et al., 2014; n Corresponding author at: Department of Health, National Institute for Health and Welfare, FI-00271 Helsinki, Finland. E-mail addresses: ilona.merikanto@helsinki.fi, ilona.merikanto@thl.fi (I. Merikanto).
http://dx.doi.org/10.1016/j.jad.2015.08.061 0165-0327/& 2015 Elsevier B.V. All rights reserved.
Konttinen et al., 2014). One study has correlated the heritability of eveningness with the tendency to depression (Toomey et al., 2015). Most of the studies reporting association between circadian typology of eveningness and depression have based on relatively small samples (Drennan et al., 1991; Chelminski et al., 1999; Gaspar-Barba et al., 2009; Hidalgo et al., 2009; Antunes et al., 2010; Hasler et al., 2010; Kim et al., 2010; Kitamura et al., 2010; Selvi et al., 2010; Abe et al., 2011; Levandovski et al., 2011; Meliska et al., 2011; Chan et al., 2014); but there are few big-scale populationbased studies as well (Merikanto et al., 2013a; Konttinen et al., 2014). In the current study, we sought to study the relationship between chronotype and depression in a more detailed way in a more representative sample size of the Finnish adult population than in our earlier study on the subject (Merikanto et al., 2013a). We also analyzed the association of chronotype with depression more thoroughly by controlling for a range of depression-attributed and potential confounding factors, including gender, age,
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education level, living status, smoking, alcohol consumption, and satisfaction with the amount of sleep the participant slept, in order to see whether the association is independent of these factors. Herein, we present results from the association of chronotype with depression indicators, as well as results from the association of chronotype and depression with health examination measurements in both genders together and separately. The health examination measurements we examined included the systolic and diastolic blood pressures, resting heart rate, weight, waist circumference, and body-mass index (BMI).
2. Methods 2.1. Participants The data of this study is based on the combined datasets from The National FINRISK 2007 Study and The National FINRISK 2012 Study, consisting in total of 10,503 participants with information on chronotype available (6089 participants from The National FINRISK 2007 Study and 4414 participants from The National FINRISK 2012 Study). Both The National FINRISK 2007 Study and The National FINRISK 2012 Study consisted of a sex- and 10-year age-group stratified random sample, aged 25–74 years, living in five geographically large areas in Finland. In both studies, from each five geographical area, 2000 inhabitants were randomly sampled from the Population Information System of the national Population Register Centre. Participants were sent self-report questionnaires and attended a health examination that took place locally between 22 January 2007 and 30 March 2007 in The National FINRISK 2007 Study and between 23 January 2012 and 2 April 2012 in The National FINRISK 2012 Study. 2.2. Assessment Chronotype was assessed in the self-report questionnaires in both Studies using six questions taken from the 19-item HorneÖstberg Morningness-Eveningness Questionnaire (MEQ) that measures the personal timing preference of the intrinsic circadian period (Horne and Östberg, 1976). These six original items correlated best with the sum score of the original 19 items in the regression analysis, explaining 83% of the variance in the sum (Hätönen et al., 2008). The sum score on the selected six MEQ items ranged from 5 (Evening-types) to 27 (Morning-types). The sum score was categorized into three classes, including the definite or moderate Morning-types (19–27 points), the Intermediatetype (13–18 points), and the definite or moderate Evening-types (5–12 points), reflecting the original MEQ sum score scaling. Depression was assessed with the same four questions in both studies as follows (the response alternatives are given in the parentheses). Question 1: “Have you had during the last 12 months at least a two-week continuous period when you have felt dispirited or depressed?” (Yes, No). Question 2: “Have you had during the last 12 months at least a two-week continuous period when you have lost interest in most of the things that normally feel good, such as hobbies or work?” (Yes, No). Question 3: “Have you been diagnosed or treated for depression by a medical doctor during the last year (12 months)?” (Yes, No). Question 4: “When is the last time you have used medication for depression?” (During the past week; 1–4 weeks ago; 1–12 months ago; Over a year ago; Never). These four questions appeared separately in the self-report questionnaires and are explicitly referred to as indicators of depression. In the analysis, the questions 1 and 2 were dichotomized together into two depression indicator categories ‘no symptoms’ and ‘one or two symptoms’ for the logistic regression, while for the linear and Poisson regressions, t-tests and chi-squared tests,
they were combined into three dichotomized categories: none vs. one or two symptoms (referred as depressive symptoms). The question regarding usage of antidepressant medication was dichotomized into “never used antidepressant medication” and “have used antidepressant medication”. 2.3. Health examination In the health examinations, systolic and diastolic blood pressures (arithmetic mean of three measurements (mmHg)), the resting heart rate (as beats in 30 s), height (cm), weight (kg), bodymass index (kg/m2) and waist circumference (cm) were measured. In The National FINRISK 2007, the health examinations took place between 10:55 a.m. and 8:10 p.m., the attendance time being at 2:50 p.m. on average. In The National FINRISK 2012, the health examinations took place between 11.00 a.m. and 8:35 p.m., the attendance time being at 2:15 p.m. on average. There were no marked differences in the assessment time by chronotype in either of The National FINRISK Studies. 2.4. Statistics The distribution of chronotypes by key sociodemographic, socioeconomic and health-related characteristics was tested with two-sided chi-square tests and t-tests and in a Supplementary analysis also separately in different gender. Binary logistic regression analyses were used to estimate the odds ratios (ORs) with 95% confidence limits (CLs) for the indicators of depression for each chronotype, after controlling for gender, age, education level, living status, regular smoking status, alcohol consumption, and experience on the amount of sleep (control variables are described in more detail in Table 1). Depressive symptoms were coded as 1¼ no symptoms and 2¼ one or two depressive symptoms. First, the crude (univariate) association with chronotype was analyzed; second, the model was controlled for gender, age; and thirdly, the model was controlled for gender, age, education level, living status, regular smoking status, alcohol consumption, and experience on the amount of sleep the participant slept. Linear regression analysis was calculated to test whether chronotype and depression are associated with each of five parameters (systolic and diastolic blood pressures, resting heart rate, weight, and waist circumference) measured in the health examination. These analyses were adjusted for gender, age, education level, living status, regular smoking status, alcohol consumption and experience on the amount of sleep the participant slept. Poisson regression analysis was calculated to test the association of chronotype and depression on alcohol consumption, and experience on the amount of sleep the participant slept, after controlling for gender, age, education level, living status, regular smoking status and either alcohol consumption or experience on the amount of sleep depending on which character was tested. Ttests and chi-square tests were used to test the differences within each chronotype regarding the health examination measurements, alcohol consumption, and experience on the amount of sleep between different depression indicator categories. All these analyses were also conducted as Supplementary analysis separately for genders. 2.5. Ethics The National FINRISK 2007 and 2012 Studies were approved by the Coordinating Ethics Committee of the Hospital District of Helsinki and Uusimaa, Finland (#20.2.2007/229/E0/06). They were conducted according to accepted international ethical standards in accordance with the Declaration of Helsinki and its amendments. All the participants gave written informed consent.
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Table 1 Sociodemographic, socioeconomic and health status characteristics by chronotype.a Chronotype, N ¼ 10,503 Morning, N ¼4851
Intermediate, N ¼ 4448
Evening, N¼ 1204
Gender (%)**** Men Women
48.1 51.9
44.0 56.0
39.5 60.5
Age (years, mean7 s.d.)****
53.8 712.9
48.9 714.1
44.2 713.4
Age group (%)**** 25–29 years 30–34 years 35–39 years 40–44 years 45–49 years 50–54 years 55–59 years 60–64 years 65–69 years 70–74 years
4.5 5.1 7.1 8.6 20.8 11.4 13.1 12.7 16.3 10.4
10.4 9.6 20.6 20.4 10.1 10.0 10.7 9.3 11.4 7.5
15.6 14.5 14.1 10.5 9.9 10.4 9.1 5.4 6.6 3.9
Education level (%)**** Basic Secondary Higher
32.4 45.5 22.1
23.3 45.1 31.6
18.6 44.9 36.5
Living status (%)**** Alone Together
25.0 75.0
36.4 73.6
38.6 61.4
Smoking (%) Never regularly Smokes presently or has smoked regularly
13.9 86.1
15.8 84.2
15.6 84.4
Alcohol consumption (%)**** At least once a month Less than once a month Not any more Never used alcohol
62.5 24.5 5.6 7.4
67.3 22.6 4.3 5.9
70.3 19.9 5.7 4.1
46.5
30.9
20.6
Rarely I cannot say
40.7 7.7 5.1
46.6 15.5 7.1
39.3 30.0 10.1
Body-mass index (mean7 s.d.)****
27.3 7 4.8
26.8 7 4.9
26.7 7 5.2
Weight (kg, mean7 s.d.)**
78.17 15.7
76.8 7 16.0
77.0 7 16.8
Waist circumference (cm, mean7 s.d.)****
93.3 713.7
91.4 7 14.0
90.7 7 14.5
Systolic blood pressure (mmHg, mean 7s.d.)****
137.5 7 20.2
132.5 7 18.4
128.6 7 17.2
Diastolic blood pressure (mmHg, mean 7s.d.)****
81.0 7 11.1
78.9 7 11.0
77.7 7 10.9
Resting heart rate (beats in 30 s, mean 7 s.d.)
34.17 5.8
34.17 5.6
Do you think you sleep enough? (%)**** Yes, nearly always Yes, often
a
34.3 7 5.7 *
Abbreviation: s.d. ¼standard deviation. Chi-square tests for non-parametric data, and t-test for parametric data, where p o 0.05; o 0.0001.
**
p o 0.01;
***
p o 0.001;
****
p
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3. Results
Table 2 Depression predicted by chronotype.a
3.1. Sociodemographic, socioeconomic and health characteristics by chronotype
Chronotype
Odds ratio
95% confidence limit Lower
There were significantly more women among Evening-types than among other chronotypes (Table 1). Evening-types were more common among younger age groups and had a lower mean age than other chronotypes, the difference being almost ten years between Evening- and Morning-types. Evening-types were the most frequent chronotype among those aged 25–34 years, Intermediate-types among those aged 35–44 years, and Morning-types among those aged 45–74 years. Significantly more Evening-types also had higher education level and were living alone rather than together with someone as compared to other chronotypes. Alcohol consumption and dissatisfaction on the amount of sleep was more common among Evening-types than other chronotypes. No significant differences were seeing between chronotypes regarding regular smoking habits. Regarding health measurements, Eveningtypes had lower BMI, waist circumference, weight and systolic as well as diastolic blood pressures than Morning-types. No difference in resting heart rate was found between the chronotypes (Table 1).
Upper
Depression diagnosed or treated by doctor in the past 12 months Model 1 (N ¼ 10,458, No N¼ 9739, Yes N ¼ 719) Evening 3.8 3.1 4.7**** Intermediate 1.8 1.5 2.2**** Model 2 (N ¼ 10,458, No N¼ 9739, Yes N ¼ 719) Evening 3.8 3.1 4.7**** Intermediate 1.8 1.5 2.2**** Model 3 (N ¼ 5394, No N ¼ 4967, Yes N ¼427) Evening 2.9 2.2 3.9**** Intermediate 1.6 1.2 2.0***
Antidepressant medication Model 1 (N ¼ 10,115, No N¼ 8986, Yes N ¼1129) Evening 3.0 2.5 Intermediate 1.6 1.4 Model 2 (N ¼ 10,115, No N¼ 8986, Yes N ¼1129) Evening 3.1 2.6 Intermediate 1.6 1.4 Model 3 (N ¼ 5215, No N ¼4554, Yes N ¼ 661) Evening 2.1 1.7 Intermediate 1.4 1.2
3.6**** 1.8**** 3.7**** 1.9**** 2.8**** 1.7***
3.2. Association of chronotype with depression Depressive symptoms Model 1 (N ¼ 10,407, No N¼ 8070, Yes N¼ 2337) Evening 3.8 3.3 Intermediate 1.7 1.5 Model 2 (N ¼ 10,407, No N¼ 8070, Yes N¼ 2337) Evening 3.2 2.8 Intermediate 1.6 2.4 Model 3 (N ¼ 5369, No N ¼ 3989, Yes N¼ 1380) Evening 2.2 1.8 Intermediate 1.4 1.2
E-types reported in all the models, even when gender, age, education level, living condition, alcohol consumption, smoking and sleeping were controlled for, having significantly higher odds for depression diagnosed or treated by a doctor in the past 12 months, higher usage of prescribed antidepressant medication and more depressive symptoms (depressed mood as well as loss of interest) than Morning-types. Also Intermediate-types had significantly higher odds for all the depression indicators than Morning-types, the odds being although lower than in Eveningtypes (Table 2).
3.7**** 2.7**** 2.6**** 1.6****
Have you had at least two weeks period during the last 12 months when you have felt depressed? Model 1 (N ¼ 10,455, No N¼ 8546, Yes N ¼ 1909) Evening 3.9 3.4 4.6**** Intermediate 1.8 1.6 2.0**** Model 2 (N ¼ 10,455, No N¼ 8546, Yes N ¼ 1909) Evening 3.4 2.9 4.0**** Intermediate 1.7 1.5 1.9**** Model 3 (N5395, No N ¼4275, Yes N ¼1120) Evening 2.2 1.8 2.7**** Intermediate 1.4 1.2 1.6****
3.3. Health examination findings by chronotype in relation to depressive symptoms Evening-types and Intermediate-types in all the depression categories had in linear regression analysis significantly lower systolic and diastolic blood pressures than Morning-types with no depressive symptoms, Evening-types having altogether significantly lower blood pressures than other chronotypes. Also Morning-types with one or two depressive symptoms also had lower systolic blood pressures than Morning-types with no depressive symptoms (Table 3). Within Morning-types (p o0.0001) and Intermediate-types the depressive symptoms were associated with lower systolic (within Morning-types and within Intermediate-types p o0.0001) as well as lower diastolic blood pressure (within Morning-types p o0.05 and within Intermediatetypes p o0.01). There were no significant differences in blood pressures among Evening-types depending on occurrence of depressive symptoms. There were also no differences between chronotypes in different depression categories regarding resting heart rate (Table 3). Evening-types with no depressive symptoms or with one or two depressive symptom had a significantly smaller waist circumference and lower weight than Morning-types with no depressive symptoms. Similarly, Evening-types with no depressive symptoms or one depressive symptom had lower BMI than Morning-types with no depressive symptoms, the significance of the difference being more in Evening-types with no depressive symptoms (Table 3). Within Evening-types there were no differences regarding these health characteristics between different
4.3**** 1.9****
Have you had at least two weeks period during the last 12 months when you have lost interest in most of the things that normally feel good? Model 1 (N ¼ 10,427, No N ¼ 8594, Yes N ¼1833) Evening 3.4 2.9 3.9**** Intermediate 1.6 1.4 1.8**** Model 2 (N ¼ 10,427, No N ¼ 8594, Yes N ¼1833) Evening 3.0 2.6 3.5**** Intermediate 1.5 1.3 1.7**** Model 3 (N ¼ 5378, No N ¼ 4256, Yes N ¼1122) Evening 2.2 1.8 2.7**** Intermediate 1.3 1.1 1.6*** p o 0.05; **p o 0.01.
*
a Model 1 crude (univariate); model 2 controlled for gender and age; model 3 controlled for gender, age, education level, living status, alcohol consumption, smoking, and sleep. Morning-types as the reference category. *** p o0.001. **** p o 0.0001.
depression indicator categories. Also Intermediate-types with no depressive symptoms or with one depressive symptom had lower weight and BMI as well as smaller waist circumference than Morning-types with no depressive symptoms (Table 3). However,
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Table 3 Mean 7 standard deviations of health examination parameters by chronotype and depressive symptoms.a
147
Table 4 Alcohol consumption and sleep by chronotype and depressive symptoms.a Chronotype
Chronotype Morning Intermediate Evening Morning-types Intermediatetypes Systolic blood pressure No depressive 138.3 7 20.3 symptoms 1 depressive symptom 134.4 7 19.3* 2 depressive 132.9 7 19.0* symptoms
Diastolic blood pressure No depressive 81.2 7 11.0 symptoms 1 depressive symptom 80.4 7 11.8 2 depressive 79.7 7 11.7 symptoms
Resting heart rate No depressive symptoms 1 depressive symptom 2 depressive symptoms
Waist circumference No depressive symptoms 1 depressive symptom 2 depressive symptoms
Weight No depressive symptoms 1 depressive symptom 2 depressive symptoms
Body-mass index No depressive symptoms 1 depressive symptom 2 depressive symptoms ***
****
Evening-types
****
133.47 18.6
129.4 7 17.5
129.7 7 18.6**** 129.5 7 16.9****
126.6 7 16.9**** 127.5 7 16.6****
79.3 7 11.0****
77.9 7 10.8****
77.5 7 11.2**** 78.2 7 11.1****
76.4 7 10.4**** 77.8 7 11.5****
34.17 5.8
34.0 7 5.7
34.17 5.8
34.17 5.5 34.0 7 5.8
34.3 7 5.4 34.2 7 5.6
34.5 7 5.8 34.6 7 5.6
91.3 7 13.8
****
90.4 7 13.8
89.2 7 13.8 93.17 15.5
****
89.9 7 14.8** 91.7 7 15.9**
78.17 15.5
76.9 7 15.7
**
78.3 7 16.3 78.5 7 17.5
74.6 7 15.6** 78.3 7 17.6
76.4 7 16.4* 77.17 18.3**
27.3 7 4.7
26.7 7 4.9****
26.5 7 5.0****
27.3 7 4.9 27.9 7 5.6
26.2 7 4.8** 27.5 7 5.4
26.4 7 5.3* 27.0 7 5.7
93.4 7 13.5 93.9 7 14.3 94.17 15.3
Alcohol consumption (%) No depressive At least once a symptoms month Less than once a month Not any more Never used alcohol 1 depressive At least once a symptom month Less than once a month Not any more Never used alcohol 2 depressive At least once a symptoms month Less than once a month Not any more Never used alcohol
77.0 7 16.3
Do you think you sleep enough? (%) No depressive Yes, nearly always symptoms Yes, often Rarely I cannot say 1 depressive Yes, nearly always symptoms Yes, often Rarely I cannot say 2 depressive Yes, nearly always symptoms Yes, often Rarely I cannot say
****
**
*
p o 0.05;
62.8
67.5
71.6
24.3
22.3
18.6
5.2 7.8
4.1 6.0
5.6 4.2
66.1
67.2
75.6
21.5
22.4
19.3
6.5 5.9
4.8 5.7
2.8 2.3
58.7
65.5
63.9
27.1
24.2
23.2
9.4 4.7
5.2 5.1
7.8 5.0
49.3
34.0****
22.5****
39.9 6.3 4.5 31.9**
47.8 12.3 5.8 21.1****
42.9 26.1 8.5 17.6****
51.9 9.4 6.8 31.8****
44.5 23.9 10.5 21.2****
37.5 33.5 11.4 17.9****
39.9 19.6 8.7
41.9 25.6 11.3
32.6 36.7 12.9
***
p o 0.001.
a
Poisson regression analyses adjusted for gender, age, education level, living status, smoking, and either alcohol consumption or sleep. Morning-types and those with no depressive symptoms as the reference categories. ** p o0.01. **** p o0.0001.
po 0.001.
a Linear regression analyses adjusted for gender, age, education level, living status, alcohol consumption, smoking, and sleep. Morning-types and those with no depressive symptoms as the reference categories. * p o 0.05. ** po 0.01. **** p o0.0001.
the more depressed the Intermediate-types were, the higher BMI (p o0.0001) and weight (p o0.0001) and the bigger waist circumference (p o0.01) they had. Also within Morning-types, the more depressed the Morning-types were, the higher the BMI was (p o0.05). 3.4. Sleep and alcohol consumption by chronotype in relation to depressive symptoms Evening-types with no depressive symptoms or with one or two depressive symptom had higher odds for feeling dissatisfied in the amount of sleep they slept, as compared to Morning-types with no depressive symptoms (Table 4). Also within Eveningtypes, the more depressed the Evening-types were, the more
dissatisfied they were in the amount of sleep they slept (p o0.0001). The same results were seen also in Intermediatetypes, as compared to Morning-types with no depressive symptoms (Table 4), as well as within Intermediate-types (p o0.0001), although not as strongly as among Evening-types. Also within Morning-types, the more depressed the Morning-types were, the more dissatisfied they were in the amount of sleep they slept (p o0.001), although not as often as among Intermediate- or Evening-types (Table 4). As compared to Morning-types with no depressive symptoms, there were no differences between chronotypes in different depression indicator categories regarding alcohol consumption (Table 4). Interestingly, within Morning-types the more depressed the Morning-types were, the less often they currently drunk but had drank more before than less depressed (p o0.001) (Table 4). 4. Discussion Our current results from a combined sample of adults derived from the general population confirmed the earlier findings of the
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increased odds for depression among the Evening-types. This association remained significant after controlling for a range of potential confounders in the final models across diverse parameters of depression. Further, the degree of the odds for depression demarcated the chronotypes in a significant way, or in other words, the Evening-types were significantly more depressed than the Intermediate-types, and the Intermediate-types were significantly more depressed than the Morning-types. Moreover, our current results extended our earlier findings (Merikanto et al., 2013a) in that now we controlled the analysis for three more factors as potential confounders (living status, alcohol consumption, and sleep), and we were able to confirm that the independent association of evening chronotype with depression remained significant. In addition, as descriptive data, we presented in the current study BMI as a new factor, and we studied the effect of age in a more detailed way as divided into 5-year age groups. Our results demonstrate that eveningness was related to the increased odds for depression regardless of sleep sufficiency or alcohol consumption. One previous study by Chan et al. (2014) also reported that Evening-types had a higher risk for depression no matter if they were sleep deprived or not. A higher prevalence of sleep problems among Evening-types (Merikanto et al., 2012) does not therefore seem to solely explain the tendency to depression among Evening-types. Our results however supported the co-occurrence of sleep problems and depression, since depression contributed to the report of poor sleep sufficiency among all chronotypes, especially among the depressed Evening-types. Resting heart rate did not differentiate the chronotypes. On the other hand, systolic blood pressure displayed two gradients. First, Morning-types had the highest values and Evening-types had the lowest ones, Intermediate-types having intermediate values. A similar gradient was seen in diastolic blood pressure. Second, the more depressed the individual was, the lower his systolic blood pressure was. The only exception here was those Evening-types who had two depressive symptoms. Beyond, Evening-types with two depressive symptoms had the highest values of waist circumference, weight, and body-mass index among the Evening-types. It is possible that Evening-types are more prone to circadian misalignment of biological rhythms, as compared to other chronotypes, since a society runs on a more morning-based rhythm. The circadian misalignment might be a link to health hazards such as depression, cardiovascular diseases, respiratory disorders, type 2 diabetes, articular and spinal diseases among Evening-types (Merikanto et al., 2013a, 2013b, 2014a, 2014b). If this were to be the case, then interventions which allow Evening-types to follow their intrinsic circadian rhythm without obligation to obey a rhythm more suitable for other chronotypes may ease depressive symptoms. 4.1. Limitations The assessment of chronotype and information about depression was based on the self-report information only, which is a limitation in our study. Physiological measurements of circadian rhythms, e.g., that of core body temperature, would be a more accurate method to assess the chronotype, but the use of such methods would have been too challenging and expensive for a big nation-wide sample of this study. Future studies are needed, where the information about symptoms and diseases are not based on self-report information but on objective measurements and diagnostic assessments. On the other hand, the big population-based sample, which is derived from a national health examination survey, is a major strength of our study. 4.2. Conclusion To conclude, our results that were based on a big population-
based adult sample confirmed that tendency towards eveningness was associated with the increased odds for depression.
Funding This work was supported by a grant from Orton Orthopaedics Hospital (to Ms. Merikanto) (Grant No. 9310/460). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
References Abe, T., Inoue, Y., Komada, Y., Nakamura, M., Asaoka, S., Kanno, M., Shibui, K., Hayashida, K., Usui, A., Takahashi, K., 2011. Relation between morningnesseveningness score and depressive symptoms among patients with delayed sleep phase syndrome. Sleep Med. 12, 680–684. Antunes, L.C., Jornada, M.N., Ramalho, L., Hidalgo, M.P., 2010. Correlation of shift work and waist circumference, body mass index, chronotype and depressive symptoms. Arq. Bras. Endocrinol. Metabol. 54, 652–656. Bahk, Y.C., Han, E., Lee, S.H., 2014. Biological rhythm differences and suicidal ideation in patients with major depressive disorder. J. Affect. Disord. 168, 294–297. Chan, J.W., Lam, S.P., Li, S.X., Yu, M.W., Chan, N.Y., Zhang, J., Wing, Y.K., 2014. Eveningness and insomnia: independent risk factors of nonremission in major depressive disorder. Sleep 37, 911–917. Chelminski, I., Ferraro, F., Petros, T., Plaud, J., 1999. An analysis of the “eveningness– morningness” dimension in “depressive” college students. J. Affect. Disord. 52, 19–29. Drennan, M., Klauber, M., Kripke, D., Goyette, L., 1991. The effects of depression and age on the Horne–Ostberg morningness–eveningness score. J. Affect. Disord. 23, 93–98. Gaspar-Barba, E., Calati, R., Cruz-Fuentes, C.S., Ontiveros-Uribe, M.P., Natale, V., De Ronchi, D., Serretti, A., 2009. Depressive symptomatology is influenced by chronotypes. J. Affect. Disord. 119, 100–106. Hasler, B.P., Allen, J.J., Sbarra, D.A., Bootzin, R.R., Bernert, R.A., 2010. Morningness– eveningness and depression: preliminary evidence for the role of the behavioral activation system and positive affect. Psychiatry Res. 30, 166–173. Hidalgo, M.P., Caumo, W., Posser, M., Coccaro, S.B., Camozzato, A.L., Chaves, M.L., 2009. Relationship between depressive mood and chronotype in healthy subjects. Psychiatry Clin. Neurosci. 63, 283–290. Horne, J.A., Östberg, O., 1976. A self-assessment questionnaire to determine morningness–eveningness in human circadian rhythms. Int. J. Chronobiol. 4, 97–110. Hätönen, T., Forsblom, S., Kieseppä, T., Lönnqvist, J., Partonen, T., 2008. Circadian phenotype in patients with the co-morbid alcohol use and bipolar disorders. Alcohol Alcohol. 43, 564–568. Kim, S.J., Lee, Y.J., Kim, H., Cho, I.H., Lee, J.Y., Cho, S.J., 2010. Age as a moderator of the association between depressive symptoms and morningness-eveningness. J. Psychosom. Res. 68, 159–164. Kitamura, S., Hida, A., Watanabe, M., Enomoto, M., Aritake-Okada, S., Moriguchi, Y., Kamei, Y., Mishima, K., 2010. Evening preference is related to the incidence of depressive states independent of sleep-wake conditions. Chronobiol. Int. 27, 1797–1812. Konttinen, H., Kronholm, E., Partonen, T., Kanerva, N., Männistö, S., Haukkala, A., 2014. Morningness-eveningness, depressive symptoms, and emotional eating: a population-based study. Chronobiol. Int. 31, 554–563. Levandovski, R., Dantas, G., Fernandes, L.C., Caumo, W., Torres, I., Roenneberg, T., Hidalgo, M.P., Allebrandt, K.V., 2011. Depression scores associate with chronotype and social jetlag in a rural population. Chronobiol. Int. 28, 771–778. Meliska, C.J., Martínez, L.F., López, A.M., Sorenson, D.L., Nowakowski, S., Parry, B.L., 2011. Relationship of morningness–eveningness questionnaire score to melatonin and sleep timing, body mass index and atypical depressive symptoms in peri- and post-menopausal women. Psychiatry Res. 30, 88–95. Merikanto, I., Kronholm, E., Peltonen, M., Laatikainen, T., Lahti, T., Partonen, T., 2012. The relation of chronotype to sleep complaints in the general Finnish population. Chronobiol. Int. 29, 311–317. Merikanto, I., Lahti, T., Kronholm, E., Peltonen, M., Laatikainen, T., Vartiainen, E., Salomaa, V., Partonen, T., 2013a. Evening types are prone to depression. Chronobiol. Int. 30, 719–725. Merikanto, I., Lahti, T., Puolijoki, H., Vanhala, M., Peltonen, M., Laatikainen, T., Vartiainen, E., Salomaa, V., Kronholm, E., Partonen, T., 2013b. Associations of chronotype and sleep with cardiovascular diseases and type 2 diabetes. Chronobiol. Int. 30, 470–477. Merikanto, I., Englund, A., Kronholm, E., Laatikainen, T., Peltonen, M., Vartiainen, E., Partonen, T., 2014a. Evening chronotypes have the increased odds for bronchial asthma and nocturnal asthma. Chronobiol. Int. 31, 95–101. Merikanto, I., Lahti, T., Seitsalo, S., Kronholm, E., Laatikainen, T., Peltonen, M., Vartiainen, E., Partonen, T., 2014b. Behavioral trait of morningness-eveningness in association with articular and spinal diseases in a population. PLoS One 9, e114635. Toomey, R., Panizzon, M.S., Kremen, W.S., Franz, C.E., Lyons, M.J., 2015. A twin-study of genetic contributions to morningness–eveningness and depression. Chronobiol. Int. 32, 303–309.
Contents lists available at ScienceDirect
Journal of Affective Disorders journal homepage: www.elsevier.com/locate/jad
Research report
Circadian preference links to depression in general adult population Ilona Merikanto a,b,c,n, Erkki Kronholm d, Markku Peltonen a, Tiina Laatikainen a,e,f, Erkki Vartiainen a, Timo Partonen a a
Department of Health, National Institute for Health and Welfare, FI-00271 Helsinki, Finland Department of Biosciences, University of Helsinki, Helsinki, Finland c Orton Orthopaedics Hospital, Helsinki, Finland d Department of Health, National Institute for Health and Welfare, Turku, Finland e Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland f Hospital District of North Karelia, Joensuu, Finland b
art ic l e i nf o
a b s t r a c t
Article history: Received 2 June 2015 Received in revised form 31 July 2015 Accepted 26 August 2015 Available online 1 September 2015
Background: Preference to time the daily activities towards the evening hours has been associated with a greater likelihood for depression in earlier studies consisting of relatively small samples. Methods: In the current study, we analyzed the relationship between chronotype and depression using a combined population-based sample of 10,503 Finnish adults aged 25 to 74 years from the two national FINRISK 2007 and 2012 health examination studies. Results: Our results confirmed that eveningness was significantly associated with the increased odds for a diagnosed depressive disorder, antidepressant medication, and depressive symptoms (p o0.0001 for each), after controlling for a range of depression-attributed and potential confounding factors. Regardless of depressive symptoms, Evening-types had lower systolic and diastolic blood pressures, a smaller waist circumference, and a lower body weight than other chronotypes. Limitations: A limitation to our study is that the assessment of chronotype and information about depression was based on the self-report information only. However, the big population-based sample, which is derived from a national health examination survey, is a major strength of our study. Conclusions: In conclusion, our study is in line the results from the previous, smaller sample size studies confirming that Evening-types have higher risk for depression than other chronotypes. This risk is elevated even among those Evening-types with sufficient amount of sleep. & 2015 Elsevier B.V. All rights reserved.
Keywords: Alcohol Body-mass index Chronobiology Diurnal Morningness Sleep
1. Introduction Earlier studies have demonstrated that individuals with the tendency towards eveningness in their preference to time the daily activities (Evening-types) bear a greater likelihood for depressive symptoms or major depression than those with the tendency being towards morningness (Drennan et al., 1991; Chelminski et al., 1999; Gaspar-Barba et al.,, 2009; Hidalgo et al.,, 2009; Antunes et al., 2010; Hasler et al., 2010; Kim et al., 2010; Kitamura et al., 2010; Selvi et al., 2010; Abe et al., 2011; Levandovski et al., 2011; Meliska et al., 2011; Merikanto et al., 2013a; Chan et al., 2014). Evening-types also seem to have greater odds for stressrelated eating and for suicide (Bahk et al., 2014; Chan et al., 2014; n Corresponding author at: Department of Health, National Institute for Health and Welfare, FI-00271 Helsinki, Finland. E-mail addresses: ilona.merikanto@helsinki.fi, ilona.merikanto@thl.fi (I. Merikanto).
http://dx.doi.org/10.1016/j.jad.2015.08.061 0165-0327/& 2015 Elsevier B.V. All rights reserved.
Konttinen et al., 2014). One study has correlated the heritability of eveningness with the tendency to depression (Toomey et al., 2015). Most of the studies reporting association between circadian typology of eveningness and depression have based on relatively small samples (Drennan et al., 1991; Chelminski et al., 1999; Gaspar-Barba et al., 2009; Hidalgo et al., 2009; Antunes et al., 2010; Hasler et al., 2010; Kim et al., 2010; Kitamura et al., 2010; Selvi et al., 2010; Abe et al., 2011; Levandovski et al., 2011; Meliska et al., 2011; Chan et al., 2014); but there are few big-scale populationbased studies as well (Merikanto et al., 2013a; Konttinen et al., 2014). In the current study, we sought to study the relationship between chronotype and depression in a more detailed way in a more representative sample size of the Finnish adult population than in our earlier study on the subject (Merikanto et al., 2013a). We also analyzed the association of chronotype with depression more thoroughly by controlling for a range of depression-attributed and potential confounding factors, including gender, age,
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education level, living status, smoking, alcohol consumption, and satisfaction with the amount of sleep the participant slept, in order to see whether the association is independent of these factors. Herein, we present results from the association of chronotype with depression indicators, as well as results from the association of chronotype and depression with health examination measurements in both genders together and separately. The health examination measurements we examined included the systolic and diastolic blood pressures, resting heart rate, weight, waist circumference, and body-mass index (BMI).
2. Methods 2.1. Participants The data of this study is based on the combined datasets from The National FINRISK 2007 Study and The National FINRISK 2012 Study, consisting in total of 10,503 participants with information on chronotype available (6089 participants from The National FINRISK 2007 Study and 4414 participants from The National FINRISK 2012 Study). Both The National FINRISK 2007 Study and The National FINRISK 2012 Study consisted of a sex- and 10-year age-group stratified random sample, aged 25–74 years, living in five geographically large areas in Finland. In both studies, from each five geographical area, 2000 inhabitants were randomly sampled from the Population Information System of the national Population Register Centre. Participants were sent self-report questionnaires and attended a health examination that took place locally between 22 January 2007 and 30 March 2007 in The National FINRISK 2007 Study and between 23 January 2012 and 2 April 2012 in The National FINRISK 2012 Study. 2.2. Assessment Chronotype was assessed in the self-report questionnaires in both Studies using six questions taken from the 19-item HorneÖstberg Morningness-Eveningness Questionnaire (MEQ) that measures the personal timing preference of the intrinsic circadian period (Horne and Östberg, 1976). These six original items correlated best with the sum score of the original 19 items in the regression analysis, explaining 83% of the variance in the sum (Hätönen et al., 2008). The sum score on the selected six MEQ items ranged from 5 (Evening-types) to 27 (Morning-types). The sum score was categorized into three classes, including the definite or moderate Morning-types (19–27 points), the Intermediatetype (13–18 points), and the definite or moderate Evening-types (5–12 points), reflecting the original MEQ sum score scaling. Depression was assessed with the same four questions in both studies as follows (the response alternatives are given in the parentheses). Question 1: “Have you had during the last 12 months at least a two-week continuous period when you have felt dispirited or depressed?” (Yes, No). Question 2: “Have you had during the last 12 months at least a two-week continuous period when you have lost interest in most of the things that normally feel good, such as hobbies or work?” (Yes, No). Question 3: “Have you been diagnosed or treated for depression by a medical doctor during the last year (12 months)?” (Yes, No). Question 4: “When is the last time you have used medication for depression?” (During the past week; 1–4 weeks ago; 1–12 months ago; Over a year ago; Never). These four questions appeared separately in the self-report questionnaires and are explicitly referred to as indicators of depression. In the analysis, the questions 1 and 2 were dichotomized together into two depression indicator categories ‘no symptoms’ and ‘one or two symptoms’ for the logistic regression, while for the linear and Poisson regressions, t-tests and chi-squared tests,
they were combined into three dichotomized categories: none vs. one or two symptoms (referred as depressive symptoms). The question regarding usage of antidepressant medication was dichotomized into “never used antidepressant medication” and “have used antidepressant medication”. 2.3. Health examination In the health examinations, systolic and diastolic blood pressures (arithmetic mean of three measurements (mmHg)), the resting heart rate (as beats in 30 s), height (cm), weight (kg), bodymass index (kg/m2) and waist circumference (cm) were measured. In The National FINRISK 2007, the health examinations took place between 10:55 a.m. and 8:10 p.m., the attendance time being at 2:50 p.m. on average. In The National FINRISK 2012, the health examinations took place between 11.00 a.m. and 8:35 p.m., the attendance time being at 2:15 p.m. on average. There were no marked differences in the assessment time by chronotype in either of The National FINRISK Studies. 2.4. Statistics The distribution of chronotypes by key sociodemographic, socioeconomic and health-related characteristics was tested with two-sided chi-square tests and t-tests and in a Supplementary analysis also separately in different gender. Binary logistic regression analyses were used to estimate the odds ratios (ORs) with 95% confidence limits (CLs) for the indicators of depression for each chronotype, after controlling for gender, age, education level, living status, regular smoking status, alcohol consumption, and experience on the amount of sleep (control variables are described in more detail in Table 1). Depressive symptoms were coded as 1¼ no symptoms and 2¼ one or two depressive symptoms. First, the crude (univariate) association with chronotype was analyzed; second, the model was controlled for gender, age; and thirdly, the model was controlled for gender, age, education level, living status, regular smoking status, alcohol consumption, and experience on the amount of sleep the participant slept. Linear regression analysis was calculated to test whether chronotype and depression are associated with each of five parameters (systolic and diastolic blood pressures, resting heart rate, weight, and waist circumference) measured in the health examination. These analyses were adjusted for gender, age, education level, living status, regular smoking status, alcohol consumption and experience on the amount of sleep the participant slept. Poisson regression analysis was calculated to test the association of chronotype and depression on alcohol consumption, and experience on the amount of sleep the participant slept, after controlling for gender, age, education level, living status, regular smoking status and either alcohol consumption or experience on the amount of sleep depending on which character was tested. Ttests and chi-square tests were used to test the differences within each chronotype regarding the health examination measurements, alcohol consumption, and experience on the amount of sleep between different depression indicator categories. All these analyses were also conducted as Supplementary analysis separately for genders. 2.5. Ethics The National FINRISK 2007 and 2012 Studies were approved by the Coordinating Ethics Committee of the Hospital District of Helsinki and Uusimaa, Finland (#20.2.2007/229/E0/06). They were conducted according to accepted international ethical standards in accordance with the Declaration of Helsinki and its amendments. All the participants gave written informed consent.
I. Merikanto et al. / Journal of Affective Disorders 188 (2015) 143–148
145
Table 1 Sociodemographic, socioeconomic and health status characteristics by chronotype.a Chronotype, N ¼ 10,503 Morning, N ¼4851
Intermediate, N ¼ 4448
Evening, N¼ 1204
Gender (%)**** Men Women
48.1 51.9
44.0 56.0
39.5 60.5
Age (years, mean7 s.d.)****
53.8 712.9
48.9 714.1
44.2 713.4
Age group (%)**** 25–29 years 30–34 years 35–39 years 40–44 years 45–49 years 50–54 years 55–59 years 60–64 years 65–69 years 70–74 years
4.5 5.1 7.1 8.6 20.8 11.4 13.1 12.7 16.3 10.4
10.4 9.6 20.6 20.4 10.1 10.0 10.7 9.3 11.4 7.5
15.6 14.5 14.1 10.5 9.9 10.4 9.1 5.4 6.6 3.9
Education level (%)**** Basic Secondary Higher
32.4 45.5 22.1
23.3 45.1 31.6
18.6 44.9 36.5
Living status (%)**** Alone Together
25.0 75.0
36.4 73.6
38.6 61.4
Smoking (%) Never regularly Smokes presently or has smoked regularly
13.9 86.1
15.8 84.2
15.6 84.4
Alcohol consumption (%)**** At least once a month Less than once a month Not any more Never used alcohol
62.5 24.5 5.6 7.4
67.3 22.6 4.3 5.9
70.3 19.9 5.7 4.1
46.5
30.9
20.6
Rarely I cannot say
40.7 7.7 5.1
46.6 15.5 7.1
39.3 30.0 10.1
Body-mass index (mean7 s.d.)****
27.3 7 4.8
26.8 7 4.9
26.7 7 5.2
Weight (kg, mean7 s.d.)**
78.17 15.7
76.8 7 16.0
77.0 7 16.8
Waist circumference (cm, mean7 s.d.)****
93.3 713.7
91.4 7 14.0
90.7 7 14.5
Systolic blood pressure (mmHg, mean 7s.d.)****
137.5 7 20.2
132.5 7 18.4
128.6 7 17.2
Diastolic blood pressure (mmHg, mean 7s.d.)****
81.0 7 11.1
78.9 7 11.0
77.7 7 10.9
Resting heart rate (beats in 30 s, mean 7 s.d.)
34.17 5.8
34.17 5.6
Do you think you sleep enough? (%)**** Yes, nearly always Yes, often
a
34.3 7 5.7 *
Abbreviation: s.d. ¼standard deviation. Chi-square tests for non-parametric data, and t-test for parametric data, where p o 0.05; o 0.0001.
**
p o 0.01;
***
p o 0.001;
****
p
146
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3. Results
Table 2 Depression predicted by chronotype.a
3.1. Sociodemographic, socioeconomic and health characteristics by chronotype
Chronotype
Odds ratio
95% confidence limit Lower
There were significantly more women among Evening-types than among other chronotypes (Table 1). Evening-types were more common among younger age groups and had a lower mean age than other chronotypes, the difference being almost ten years between Evening- and Morning-types. Evening-types were the most frequent chronotype among those aged 25–34 years, Intermediate-types among those aged 35–44 years, and Morning-types among those aged 45–74 years. Significantly more Evening-types also had higher education level and were living alone rather than together with someone as compared to other chronotypes. Alcohol consumption and dissatisfaction on the amount of sleep was more common among Evening-types than other chronotypes. No significant differences were seeing between chronotypes regarding regular smoking habits. Regarding health measurements, Eveningtypes had lower BMI, waist circumference, weight and systolic as well as diastolic blood pressures than Morning-types. No difference in resting heart rate was found between the chronotypes (Table 1).
Upper
Depression diagnosed or treated by doctor in the past 12 months Model 1 (N ¼ 10,458, No N¼ 9739, Yes N ¼ 719) Evening 3.8 3.1 4.7**** Intermediate 1.8 1.5 2.2**** Model 2 (N ¼ 10,458, No N¼ 9739, Yes N ¼ 719) Evening 3.8 3.1 4.7**** Intermediate 1.8 1.5 2.2**** Model 3 (N ¼ 5394, No N ¼ 4967, Yes N ¼427) Evening 2.9 2.2 3.9**** Intermediate 1.6 1.2 2.0***
Antidepressant medication Model 1 (N ¼ 10,115, No N¼ 8986, Yes N ¼1129) Evening 3.0 2.5 Intermediate 1.6 1.4 Model 2 (N ¼ 10,115, No N¼ 8986, Yes N ¼1129) Evening 3.1 2.6 Intermediate 1.6 1.4 Model 3 (N ¼ 5215, No N ¼4554, Yes N ¼ 661) Evening 2.1 1.7 Intermediate 1.4 1.2
3.6**** 1.8**** 3.7**** 1.9**** 2.8**** 1.7***
3.2. Association of chronotype with depression Depressive symptoms Model 1 (N ¼ 10,407, No N¼ 8070, Yes N¼ 2337) Evening 3.8 3.3 Intermediate 1.7 1.5 Model 2 (N ¼ 10,407, No N¼ 8070, Yes N¼ 2337) Evening 3.2 2.8 Intermediate 1.6 2.4 Model 3 (N ¼ 5369, No N ¼ 3989, Yes N¼ 1380) Evening 2.2 1.8 Intermediate 1.4 1.2
E-types reported in all the models, even when gender, age, education level, living condition, alcohol consumption, smoking and sleeping were controlled for, having significantly higher odds for depression diagnosed or treated by a doctor in the past 12 months, higher usage of prescribed antidepressant medication and more depressive symptoms (depressed mood as well as loss of interest) than Morning-types. Also Intermediate-types had significantly higher odds for all the depression indicators than Morning-types, the odds being although lower than in Eveningtypes (Table 2).
3.7**** 2.7**** 2.6**** 1.6****
Have you had at least two weeks period during the last 12 months when you have felt depressed? Model 1 (N ¼ 10,455, No N¼ 8546, Yes N ¼ 1909) Evening 3.9 3.4 4.6**** Intermediate 1.8 1.6 2.0**** Model 2 (N ¼ 10,455, No N¼ 8546, Yes N ¼ 1909) Evening 3.4 2.9 4.0**** Intermediate 1.7 1.5 1.9**** Model 3 (N5395, No N ¼4275, Yes N ¼1120) Evening 2.2 1.8 2.7**** Intermediate 1.4 1.2 1.6****
3.3. Health examination findings by chronotype in relation to depressive symptoms Evening-types and Intermediate-types in all the depression categories had in linear regression analysis significantly lower systolic and diastolic blood pressures than Morning-types with no depressive symptoms, Evening-types having altogether significantly lower blood pressures than other chronotypes. Also Morning-types with one or two depressive symptoms also had lower systolic blood pressures than Morning-types with no depressive symptoms (Table 3). Within Morning-types (p o0.0001) and Intermediate-types the depressive symptoms were associated with lower systolic (within Morning-types and within Intermediate-types p o0.0001) as well as lower diastolic blood pressure (within Morning-types p o0.05 and within Intermediatetypes p o0.01). There were no significant differences in blood pressures among Evening-types depending on occurrence of depressive symptoms. There were also no differences between chronotypes in different depression categories regarding resting heart rate (Table 3). Evening-types with no depressive symptoms or with one or two depressive symptom had a significantly smaller waist circumference and lower weight than Morning-types with no depressive symptoms. Similarly, Evening-types with no depressive symptoms or one depressive symptom had lower BMI than Morning-types with no depressive symptoms, the significance of the difference being more in Evening-types with no depressive symptoms (Table 3). Within Evening-types there were no differences regarding these health characteristics between different
4.3**** 1.9****
Have you had at least two weeks period during the last 12 months when you have lost interest in most of the things that normally feel good? Model 1 (N ¼ 10,427, No N ¼ 8594, Yes N ¼1833) Evening 3.4 2.9 3.9**** Intermediate 1.6 1.4 1.8**** Model 2 (N ¼ 10,427, No N ¼ 8594, Yes N ¼1833) Evening 3.0 2.6 3.5**** Intermediate 1.5 1.3 1.7**** Model 3 (N ¼ 5378, No N ¼ 4256, Yes N ¼1122) Evening 2.2 1.8 2.7**** Intermediate 1.3 1.1 1.6*** p o 0.05; **p o 0.01.
*
a Model 1 crude (univariate); model 2 controlled for gender and age; model 3 controlled for gender, age, education level, living status, alcohol consumption, smoking, and sleep. Morning-types as the reference category. *** p o0.001. **** p o 0.0001.
depression indicator categories. Also Intermediate-types with no depressive symptoms or with one depressive symptom had lower weight and BMI as well as smaller waist circumference than Morning-types with no depressive symptoms (Table 3). However,
I. Merikanto et al. / Journal of Affective Disorders 188 (2015) 143–148
Table 3 Mean 7 standard deviations of health examination parameters by chronotype and depressive symptoms.a
147
Table 4 Alcohol consumption and sleep by chronotype and depressive symptoms.a Chronotype
Chronotype Morning Intermediate Evening Morning-types Intermediatetypes Systolic blood pressure No depressive 138.3 7 20.3 symptoms 1 depressive symptom 134.4 7 19.3* 2 depressive 132.9 7 19.0* symptoms
Diastolic blood pressure No depressive 81.2 7 11.0 symptoms 1 depressive symptom 80.4 7 11.8 2 depressive 79.7 7 11.7 symptoms
Resting heart rate No depressive symptoms 1 depressive symptom 2 depressive symptoms
Waist circumference No depressive symptoms 1 depressive symptom 2 depressive symptoms
Weight No depressive symptoms 1 depressive symptom 2 depressive symptoms
Body-mass index No depressive symptoms 1 depressive symptom 2 depressive symptoms ***
****
Evening-types
****
133.47 18.6
129.4 7 17.5
129.7 7 18.6**** 129.5 7 16.9****
126.6 7 16.9**** 127.5 7 16.6****
79.3 7 11.0****
77.9 7 10.8****
77.5 7 11.2**** 78.2 7 11.1****
76.4 7 10.4**** 77.8 7 11.5****
34.17 5.8
34.0 7 5.7
34.17 5.8
34.17 5.5 34.0 7 5.8
34.3 7 5.4 34.2 7 5.6
34.5 7 5.8 34.6 7 5.6
91.3 7 13.8
****
90.4 7 13.8
89.2 7 13.8 93.17 15.5
****
89.9 7 14.8** 91.7 7 15.9**
78.17 15.5
76.9 7 15.7
**
78.3 7 16.3 78.5 7 17.5
74.6 7 15.6** 78.3 7 17.6
76.4 7 16.4* 77.17 18.3**
27.3 7 4.7
26.7 7 4.9****
26.5 7 5.0****
27.3 7 4.9 27.9 7 5.6
26.2 7 4.8** 27.5 7 5.4
26.4 7 5.3* 27.0 7 5.7
93.4 7 13.5 93.9 7 14.3 94.17 15.3
Alcohol consumption (%) No depressive At least once a symptoms month Less than once a month Not any more Never used alcohol 1 depressive At least once a symptom month Less than once a month Not any more Never used alcohol 2 depressive At least once a symptoms month Less than once a month Not any more Never used alcohol
77.0 7 16.3
Do you think you sleep enough? (%) No depressive Yes, nearly always symptoms Yes, often Rarely I cannot say 1 depressive Yes, nearly always symptoms Yes, often Rarely I cannot say 2 depressive Yes, nearly always symptoms Yes, often Rarely I cannot say
****
**
*
p o 0.05;
62.8
67.5
71.6
24.3
22.3
18.6
5.2 7.8
4.1 6.0
5.6 4.2
66.1
67.2
75.6
21.5
22.4
19.3
6.5 5.9
4.8 5.7
2.8 2.3
58.7
65.5
63.9
27.1
24.2
23.2
9.4 4.7
5.2 5.1
7.8 5.0
49.3
34.0****
22.5****
39.9 6.3 4.5 31.9**
47.8 12.3 5.8 21.1****
42.9 26.1 8.5 17.6****
51.9 9.4 6.8 31.8****
44.5 23.9 10.5 21.2****
37.5 33.5 11.4 17.9****
39.9 19.6 8.7
41.9 25.6 11.3
32.6 36.7 12.9
***
p o 0.001.
a
Poisson regression analyses adjusted for gender, age, education level, living status, smoking, and either alcohol consumption or sleep. Morning-types and those with no depressive symptoms as the reference categories. ** p o0.01. **** p o0.0001.
po 0.001.
a Linear regression analyses adjusted for gender, age, education level, living status, alcohol consumption, smoking, and sleep. Morning-types and those with no depressive symptoms as the reference categories. * p o 0.05. ** po 0.01. **** p o0.0001.
the more depressed the Intermediate-types were, the higher BMI (p o0.0001) and weight (p o0.0001) and the bigger waist circumference (p o0.01) they had. Also within Morning-types, the more depressed the Morning-types were, the higher the BMI was (p o0.05). 3.4. Sleep and alcohol consumption by chronotype in relation to depressive symptoms Evening-types with no depressive symptoms or with one or two depressive symptom had higher odds for feeling dissatisfied in the amount of sleep they slept, as compared to Morning-types with no depressive symptoms (Table 4). Also within Eveningtypes, the more depressed the Evening-types were, the more
dissatisfied they were in the amount of sleep they slept (p o0.0001). The same results were seen also in Intermediatetypes, as compared to Morning-types with no depressive symptoms (Table 4), as well as within Intermediate-types (p o0.0001), although not as strongly as among Evening-types. Also within Morning-types, the more depressed the Morning-types were, the more dissatisfied they were in the amount of sleep they slept (p o0.001), although not as often as among Intermediate- or Evening-types (Table 4). As compared to Morning-types with no depressive symptoms, there were no differences between chronotypes in different depression indicator categories regarding alcohol consumption (Table 4). Interestingly, within Morning-types the more depressed the Morning-types were, the less often they currently drunk but had drank more before than less depressed (p o0.001) (Table 4). 4. Discussion Our current results from a combined sample of adults derived from the general population confirmed the earlier findings of the
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increased odds for depression among the Evening-types. This association remained significant after controlling for a range of potential confounders in the final models across diverse parameters of depression. Further, the degree of the odds for depression demarcated the chronotypes in a significant way, or in other words, the Evening-types were significantly more depressed than the Intermediate-types, and the Intermediate-types were significantly more depressed than the Morning-types. Moreover, our current results extended our earlier findings (Merikanto et al., 2013a) in that now we controlled the analysis for three more factors as potential confounders (living status, alcohol consumption, and sleep), and we were able to confirm that the independent association of evening chronotype with depression remained significant. In addition, as descriptive data, we presented in the current study BMI as a new factor, and we studied the effect of age in a more detailed way as divided into 5-year age groups. Our results demonstrate that eveningness was related to the increased odds for depression regardless of sleep sufficiency or alcohol consumption. One previous study by Chan et al. (2014) also reported that Evening-types had a higher risk for depression no matter if they were sleep deprived or not. A higher prevalence of sleep problems among Evening-types (Merikanto et al., 2012) does not therefore seem to solely explain the tendency to depression among Evening-types. Our results however supported the co-occurrence of sleep problems and depression, since depression contributed to the report of poor sleep sufficiency among all chronotypes, especially among the depressed Evening-types. Resting heart rate did not differentiate the chronotypes. On the other hand, systolic blood pressure displayed two gradients. First, Morning-types had the highest values and Evening-types had the lowest ones, Intermediate-types having intermediate values. A similar gradient was seen in diastolic blood pressure. Second, the more depressed the individual was, the lower his systolic blood pressure was. The only exception here was those Evening-types who had two depressive symptoms. Beyond, Evening-types with two depressive symptoms had the highest values of waist circumference, weight, and body-mass index among the Evening-types. It is possible that Evening-types are more prone to circadian misalignment of biological rhythms, as compared to other chronotypes, since a society runs on a more morning-based rhythm. The circadian misalignment might be a link to health hazards such as depression, cardiovascular diseases, respiratory disorders, type 2 diabetes, articular and spinal diseases among Evening-types (Merikanto et al., 2013a, 2013b, 2014a, 2014b). If this were to be the case, then interventions which allow Evening-types to follow their intrinsic circadian rhythm without obligation to obey a rhythm more suitable for other chronotypes may ease depressive symptoms. 4.1. Limitations The assessment of chronotype and information about depression was based on the self-report information only, which is a limitation in our study. Physiological measurements of circadian rhythms, e.g., that of core body temperature, would be a more accurate method to assess the chronotype, but the use of such methods would have been too challenging and expensive for a big nation-wide sample of this study. Future studies are needed, where the information about symptoms and diseases are not based on self-report information but on objective measurements and diagnostic assessments. On the other hand, the big population-based sample, which is derived from a national health examination survey, is a major strength of our study. 4.2. Conclusion To conclude, our results that were based on a big population-
based adult sample confirmed that tendency towards eveningness was associated with the increased odds for depression.
Funding This work was supported by a grant from Orton Orthopaedics Hospital (to Ms. Merikanto) (Grant No. 9310/460). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
References Abe, T., Inoue, Y., Komada, Y., Nakamura, M., Asaoka, S., Kanno, M., Shibui, K., Hayashida, K., Usui, A., Takahashi, K., 2011. Relation between morningnesseveningness score and depressive symptoms among patients with delayed sleep phase syndrome. Sleep Med. 12, 680–684. Antunes, L.C., Jornada, M.N., Ramalho, L., Hidalgo, M.P., 2010. Correlation of shift work and waist circumference, body mass index, chronotype and depressive symptoms. Arq. Bras. Endocrinol. Metabol. 54, 652–656. Bahk, Y.C., Han, E., Lee, S.H., 2014. Biological rhythm differences and suicidal ideation in patients with major depressive disorder. J. Affect. Disord. 168, 294–297. Chan, J.W., Lam, S.P., Li, S.X., Yu, M.W., Chan, N.Y., Zhang, J., Wing, Y.K., 2014. Eveningness and insomnia: independent risk factors of nonremission in major depressive disorder. Sleep 37, 911–917. Chelminski, I., Ferraro, F., Petros, T., Plaud, J., 1999. An analysis of the “eveningness– morningness” dimension in “depressive” college students. J. Affect. Disord. 52, 19–29. Drennan, M., Klauber, M., Kripke, D., Goyette, L., 1991. The effects of depression and age on the Horne–Ostberg morningness–eveningness score. J. Affect. Disord. 23, 93–98. Gaspar-Barba, E., Calati, R., Cruz-Fuentes, C.S., Ontiveros-Uribe, M.P., Natale, V., De Ronchi, D., Serretti, A., 2009. Depressive symptomatology is influenced by chronotypes. J. Affect. Disord. 119, 100–106. Hasler, B.P., Allen, J.J., Sbarra, D.A., Bootzin, R.R., Bernert, R.A., 2010. Morningness– eveningness and depression: preliminary evidence for the role of the behavioral activation system and positive affect. Psychiatry Res. 30, 166–173. Hidalgo, M.P., Caumo, W., Posser, M., Coccaro, S.B., Camozzato, A.L., Chaves, M.L., 2009. Relationship between depressive mood and chronotype in healthy subjects. Psychiatry Clin. Neurosci. 63, 283–290. Horne, J.A., Östberg, O., 1976. A self-assessment questionnaire to determine morningness–eveningness in human circadian rhythms. Int. J. Chronobiol. 4, 97–110. Hätönen, T., Forsblom, S., Kieseppä, T., Lönnqvist, J., Partonen, T., 2008. Circadian phenotype in patients with the co-morbid alcohol use and bipolar disorders. Alcohol Alcohol. 43, 564–568. Kim, S.J., Lee, Y.J., Kim, H., Cho, I.H., Lee, J.Y., Cho, S.J., 2010. Age as a moderator of the association between depressive symptoms and morningness-eveningness. J. Psychosom. Res. 68, 159–164. Kitamura, S., Hida, A., Watanabe, M., Enomoto, M., Aritake-Okada, S., Moriguchi, Y., Kamei, Y., Mishima, K., 2010. Evening preference is related to the incidence of depressive states independent of sleep-wake conditions. Chronobiol. Int. 27, 1797–1812. Konttinen, H., Kronholm, E., Partonen, T., Kanerva, N., Männistö, S., Haukkala, A., 2014. Morningness-eveningness, depressive symptoms, and emotional eating: a population-based study. Chronobiol. Int. 31, 554–563. Levandovski, R., Dantas, G., Fernandes, L.C., Caumo, W., Torres, I., Roenneberg, T., Hidalgo, M.P., Allebrandt, K.V., 2011. Depression scores associate with chronotype and social jetlag in a rural population. Chronobiol. Int. 28, 771–778. Meliska, C.J., Martínez, L.F., López, A.M., Sorenson, D.L., Nowakowski, S., Parry, B.L., 2011. Relationship of morningness–eveningness questionnaire score to melatonin and sleep timing, body mass index and atypical depressive symptoms in peri- and post-menopausal women. Psychiatry Res. 30, 88–95. Merikanto, I., Kronholm, E., Peltonen, M., Laatikainen, T., Lahti, T., Partonen, T., 2012. The relation of chronotype to sleep complaints in the general Finnish population. Chronobiol. Int. 29, 311–317. Merikanto, I., Lahti, T., Kronholm, E., Peltonen, M., Laatikainen, T., Vartiainen, E., Salomaa, V., Partonen, T., 2013a. Evening types are prone to depression. Chronobiol. Int. 30, 719–725. Merikanto, I., Lahti, T., Puolijoki, H., Vanhala, M., Peltonen, M., Laatikainen, T., Vartiainen, E., Salomaa, V., Kronholm, E., Partonen, T., 2013b. Associations of chronotype and sleep with cardiovascular diseases and type 2 diabetes. Chronobiol. Int. 30, 470–477. Merikanto, I., Englund, A., Kronholm, E., Laatikainen, T., Peltonen, M., Vartiainen, E., Partonen, T., 2014a. Evening chronotypes have the increased odds for bronchial asthma and nocturnal asthma. Chronobiol. Int. 31, 95–101. Merikanto, I., Lahti, T., Seitsalo, S., Kronholm, E., Laatikainen, T., Peltonen, M., Vartiainen, E., Partonen, T., 2014b. Behavioral trait of morningness-eveningness in association with articular and spinal diseases in a population. PLoS One 9, e114635. Toomey, R., Panizzon, M.S., Kremen, W.S., Franz, C.E., Lyons, M.J., 2015. A twin-study of genetic contributions to morningness–eveningness and depression. Chronobiol. Int. 32, 303–309.