Association of Delayed Sleep/Wake Rhythm with Depression During the First COVID-19 Lockdown in France

Figures & data

Table 1 Demographic Characteristics of the Participants

Variables	Participants (n = 2513)
Gender, n (%)
Women	1937 (77%)
Age, median (Q1, Q3)	39 (30, 48) (N=2286)*
Familial situation
Marital status, n (%)
Single	664 (26%)
Unmarried cohabitation	481 (19%)
Civil union	326 (13%)
Married	815 (32%)
Divorced	201 (9%)
Widowed	26 (1%)
Children, n (%)
No	1102 (44%)
Yes	1411 (56%)
Number of children, mean (SD)	1.13 (1.18)
Children < 18 years)	664 (26%)
Housing, n (%)	(N=2510)*
Flat	1477 (59%)
House	1027 (41%)
Other	6 (0.2%)
Median (Q1, Q3) size of dwelling in m^2	85 (62, 115) (N=2471)
Space outside the dwelling n (%)	(N=2510)*
No	624 (25%)
Yes	1886 (75%)
Profession, n (%)
Student	206 (8%)
Employee	1679 (67%)
Retired	184 (7%)
No profession	37 (2%)
Looking for a job	108 (4%)
Invalid/disabled	35 (1%)
Self-employed	200 (8%)
Other	64 (3%)
Working hours before lockdown, n (%)	(N=1936)*
Daytime schedule	1671 (86%)
Night shift	27 (1%)
Irregular, alternating or shift work	238 (12%)
Working pattern during lockdown, n (%)	(N=2009)*
Time off	507 (26%)
Work on site	304 (16%)
Work on site + from home	182 (9%)
Exclusive work from home	943 (49%)

Notes: *Missing data, the number of participants is indicated. Note that percentages may not total 100 due to rounding.

Table 2 Psychiatric Medical Past of the Participant

Follow-Up for a Psychiatric Condition or Addiction n (%)	(N=2511)*
No	1965 (78%)
Past	348 (14%)
Yes	198 (8%)
Depression n (%)	391 (16%)
Bipolar disorder n (%)	24 (1%)
Anxiety disorder n (%)	143 (6%)
Sleep disorder n (%)	104 (4%)
Psychotic disorder n (%)	8 (0.3%)
Post-Traumatic Stress Disorder n (%)	77 (3%)
Addiction n (%)	52 (2%)
Neurodevelopmental disorder n (%)	13 (0.5%)
Eating disorder n (%)	84 (3%)
Other n (%)	35 (1%)

Notes: Note that some participants had more than one present or past psychiatric condition *Missing data, the number of participants is indicated. Note that percentages may not total 100 due to rounding.

Table 3 Distribution of Phq-9 Scores Among Participants

Severity of Depression
No depression	789 (31%)
Mild depression	894 (36%)
Moderate depression	495 (20%)
Moderately severe depression	222 (9%)
Severe depression	113 (5%)

Note: Note that percentages may not total 100 due to rounding.

Figure 1 MSFsc change between pre- and per-lockdown. The median (Q1, Q3) MSFsc increased from 3:30:00 (3:00:00, 04:19:00) before the lockdown to 4:00:00 (03:17:00, 05:00:00) during the lockdown.

Table 4 Univariate Analysis of the PHQ-9 Score

Variable	Beta	95% CI^a	p-value
Age	−0.09	−0.11, −0.07	<0.001
Gender
Female	—	—
Male	−1.3	−1.9, −0.81	<0.001
Change in MSF_(h)	0.81	0.60, 1.0	<0.001
Circadian preference
Neutral	—	—
Morning	−1.5	−2.0, −1.1	<0.001
Evening	2.6	1.9, 3.3	<0.001
Housing
Apartment	—	—
House	−1.0	−1.4, −0.55	<0.001
Marital status
Single	—	—
Cohabiting	−2.1	−2.7, −1.4	<0.001
Civil union	−2.6	−3.3, −1.8	<0.001
Married	−2.9	−3.5, −2.4	<0.001
Divorced	−1.2	−2.1, −0.32	0.007
Widowed	−2.9	−5.1, −0.75	0.008

Abbreviation: ^aCI, confidence interval.

Table 5 Multivariate Analysis of PHQ-9 Score

Variable	Beta	95% CI^a	p-value
Age	−0.06	−0.08, −0.04	<0.001
Gender
Female	—	—
Male	−1.2	−1.7, −0.65	<0.001
Change in MSF_(h)	0.50	0.28, 0.72	<0.001
Circadian preference
Neutral	—	—
Morning	−1.0	−1.5, −0.48	<0.001
Evening	2.0	1.3, 2.7	<0.001
Housing
Apartment	—	—
House	−0.41	−0.88, 0.06	0.068
Marital status
Single	—	—
Cohabiting	−2.0	−2.6, −1.3	<0.001
Civil union	−1.9	−2.7, −1.2	<0.001
Married	−1.5	−2.1, −0.85	<0.001
Divorced	0.05	−0.88, 1.0	0.915
Widowed	0.03	−2.3, 2.4	>0.982

Abbreviation: ^aCI, confidence interval.

Figure 2 Correlation between change in MSFsc and depression symptoms. The depression severity score as assessed by the PHQ-9 scale is positively correlated with the change in MSFsc between pre- and per-lockdown period (expressed in hours, h). Note that a negative MSFsc shift indicates a phase advance and a positive MSFsc shift indicates a phase delay.