Published May 26, 2026
| Version v1
Acyclic Directed Mixed Graph
Open
Causal relationship between nights shifts and depressive symptoms
Contributors
-
Melpomeni Bazaka1
- 1 Utrecht University
Visualisation
Description
The directed acyclic graph (DAG) represents the hypothesized relationships between night shift work and depression, including potential confounding and mediating variables. Night shifts were considered the main exposure and depression the outcome of interest. Sociodemographic and lifestyle-related factors, including age, sex, education, marital status, smoking, alcohol consumption, BMI, physical activity, chronotype, sleep quality, and study center, were included as covariates based on their potential influence on both the exposure and the outcome. The DAG also includes interrelationships among these variables, reflecting plausible causal pathways identified in the literature.
According to the DAG, the minimal sufficient adjustment set for statistical models contained age, center, chronotype, education, marital status, and sex for estimating the total effect of night shift work on depressive symptoms. The fully adjusted models also accounted for the potential mediating variables smoking and physical activity. Alcohol consumption, sleep quality, and BMI were considered collider variables based on the DAG structure and were therefore not included in the statistical adjustment models.
Code
Original
The graph exactly as it was submitted.
opencausal_tbvvzwhj.txtDerived
The same graph, converted to other common formats.
This JSON follows CausalJSON 0.2, the Open Causal Graph Format.
{
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"graph": {
"id": "tbvvzwhj",
"version": 1,
"title": "Causal relationship between nights shifts and depressive symptoms",
"description": "The directed acyclic graph (DAG) represents the hypothesized relationships between night shift work and depression, including potential confounding and mediating variables. Night shifts were considered the main exposure and depression the outcome of interest. Sociodemographic and lifestyle-related factors, including age, sex, education, marital status, smoking, alcohol consumption, BMI, physical activity, chronotype, sleep quality, and study center, were included as covariates based on their potential influence on both the exposure and the outcome. The DAG also includes interrelationships among these variables, reflecting plausible causal pathways identified in the literature. \r\n\r\nAccording to the DAG, the minimal sufficient adjustment set for statistical models contained age, center, chronotype, education, marital status, and sex for estimating the total effect of night shift work on depressive symptoms. The fully adjusted models also accounted for the potential mediating variables smoking and physical activity. Alcohol consumption, sleep quality, and BMI were considered collider variables based on the DAG structure and were therefore not included in the statistical adjustment models.",
"type": "admg",
"created": "2026-05-26T10:56:22+00:00",
"authors": [
{
"given_name": "Melpomeni",
"family_name": "Bazaka",
"orcid": "0009-0005-4396-877X",
"affiliations": [
{
"name": "Utrecht University"
}
]
}
],
"submitter": {
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"orcid": "0009-0005-4396-877X"
},
"license": "CC-BY-4.0",
"rights_url": "https://creativecommons.org/licenses/by/4.0/legalcode",
"publisher": "Open Causal",
"language": "en",
"layout": {
"coordinate_system": "screen"
}
},
"nodes": [
{
"id": "Marital_status",
"label": "Marital status",
"position": {
"x": 1.041,
"y": -0.905
}
},
{
"id": "Night_Shifts",
"label": "Night Shifts",
"role": "exposure",
"position": {
"x": -2.107,
"y": 0.064
}
},
{
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}
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{
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},
{
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{
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{
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{
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{
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}
},
{
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{
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"position": {
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}
},
{
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"position": {
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}
},
{
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}
}
],
"edges": [
{
"source": "Marital_status",
"target": "Night_Shifts",
"type": "directed"
},
{
"source": "Marital_status",
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"type": "directed"
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{
"source": "Marital_status",
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{
"source": "Marital_status",
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{
"source": "Marital_status",
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{
"source": "Marital_status",
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"type": "directed"
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{
"source": "Night_Shifts",
"target": "Physical_activity",
"type": "directed"
},
{
"source": "Night_Shifts",
"target": "Sleep_quality",
"type": "directed"
},
{
"source": "Night_Shifts",
"target": "Alcohol",
"type": "directed"
},
{
"source": "Night_Shifts",
"target": "BMI",
"type": "directed"
},
{
"source": "Night_Shifts",
"target": "Depression",
"type": "directed"
},
{
"source": "Night_Shifts",
"target": "Smoking",
"type": "directed"
},
{
"source": "Physical_activity",
"target": "Sleep_quality",
"type": "directed"
},
{
"source": "Physical_activity",
"target": "Depression",
"type": "directed"
},
{
"source": "Physical_activity",
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"type": "bidirected"
},
{
"source": "Sleep_quality",
"target": "Alcohol",
"type": "bidirected"
},
{
"source": "Age",
"target": "Marital_status",
"type": "directed"
},
{
"source": "Age",
"target": "Night_Shifts",
"type": "directed"
},
{
"source": "Age",
"target": "Physical_activity",
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},
{
"source": "Age",
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},
{
"source": "Age",
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{
"source": "Age",
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{
"source": "Age",
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},
{
"source": "Age",
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},
{
"source": "Age",
"target": "Smoking",
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},
{
"source": "Alcohol",
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},
{
"source": "Alcohol",
"target": "Depression",
"type": "bidirected"
},
{
"source": "Alcohol",
"target": "Smoking",
"type": "bidirected"
},
{
"source": "BMI",
"target": "Sleep_quality",
"type": "directed"
},
{
"source": "BMI",
"target": "Depression",
"type": "bidirected"
},
{
"source": "Center",
"target": "Marital_status",
"type": "directed"
},
{
"source": "Center",
"target": "Physical_activity",
"type": "directed"
},
{
"source": "Center",
"target": "Alcohol",
"type": "directed"
},
{
"source": "Center",
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{
"source": "Center",
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{
"source": "Center",
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},
{
"source": "Center",
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{
"source": "Chronotype",
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"type": "directed"
},
{
"source": "Chronotype",
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},
{
"source": "Chronotype",
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},
{
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},
{
"source": "Chronotype",
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},
{
"source": "Chronotype",
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},
{
"source": "Chronotype",
"target": "Smoking",
"type": "directed"
},
{
"source": "Depression",
"target": "Sleep_quality",
"type": "directed"
},
{
"source": "Depression",
"target": "Smoking",
"type": "bidirected"
},
{
"source": "Education",
"target": "Marital_status",
"type": "directed"
},
{
"source": "Education",
"target": "Night_Shifts",
"type": "directed"
},
{
"source": "Education",
"target": "Physical_activity",
"type": "directed"
},
{
"source": "Education",
"target": "BMI",
"type": "directed"
},
{
"source": "Education",
"target": "Depression",
"type": "directed"
},
{
"source": "Sex",
"target": "Night_Shifts",
"type": "directed"
},
{
"source": "Sex",
"target": "Physical_activity",
"type": "directed"
},
{
"source": "Sex",
"target": "Sleep_quality",
"type": "directed"
},
{
"source": "Sex",
"target": "Alcohol",
"type": "directed"
},
{
"source": "Sex",
"target": "Chronotype",
"type": "directed"
},
{
"source": "Sex",
"target": "Depression",
"type": "directed"
},
{
"source": "Sex",
"target": "Education",
"type": "directed"
},
{
"source": "Sex",
"target": "Smoking",
"type": "directed"
},
{
"source": "Smoking",
"target": "Physical_activity",
"type": "directed"
},
{
"source": "Smoking",
"target": "Sleep_quality",
"type": "directed"
},
{
"source": "Smoking",
"target": "BMI",
"type": "directed"
}
]
}
source,target,edge_type Marital status,Night Shifts,directed Marital status,Physical activity,directed Marital status,Alcohol,directed Marital status,BMI,directed Marital status,Depression,directed Marital status,Smoking,directed Night Shifts,Physical activity,directed Night Shifts,Sleep quality,directed Night Shifts,Alcohol,directed Night Shifts,BMI,directed Night Shifts,Depression,directed Night Shifts,Smoking,directed Physical activity,Sleep quality,directed Physical activity,Depression,directed Physical activity,BMI,bidirected Sleep quality,Alcohol,bidirected Age,Marital status,directed Age,Night Shifts,directed Age,Physical activity,directed Age,Sleep quality,directed Age,Alcohol,directed Age,Chronotype,directed Age,Depression,directed Age,Education,directed Age,Smoking,directed Alcohol,BMI,directed Alcohol,Depression,bidirected Alcohol,Smoking,bidirected BMI,Sleep quality,directed BMI,Depression,bidirected Center,Marital status,directed Center,Physical activity,directed Center,Alcohol,directed Center,BMI,directed Center,Depression,directed Center,Education,directed Center,Smoking,directed Chronotype,Night Shifts,directed Chronotype,Physical activity,directed Chronotype,Sleep quality,directed Chronotype,Alcohol,directed Chronotype,BMI,directed Chronotype,Depression,directed Chronotype,Smoking,directed Depression,Sleep quality,directed Depression,Smoking,bidirected Education,Marital status,directed Education,Night Shifts,directed Education,Physical activity,directed Education,BMI,directed Education,Depression,directed Sex,Night Shifts,directed Sex,Physical activity,directed Sex,Sleep quality,directed Sex,Alcohol,directed Sex,Chronotype,directed Sex,Depression,directed Sex,Education,directed Sex,Smoking,directed Smoking,Physical activity,directed Smoking,Sleep quality,directed Smoking,BMI,directed
dag {
"Marital status" [adjusted,pos="1.041,-0.905"]
"Night Shifts" [exposure,pos="-2.107,0.064"]
"Physical activity" [pos="0.373,1.627"]
"Sleep quality" [pos="-0.424,1.828"]
Age [adjusted,pos="0.651,-1.738"]
Alcohol [pos="-1.178,1.640"]
BMI [pos="0.962,1.178"]
Center [adjusted,pos="-0.034,-2.147"]
Chronotype [adjusted,pos="-0.857,-2.114"]
Depression [outcome,pos="1.295,0.109"]
Education [adjusted,pos="-1.864,-0.923"]
Sex [adjusted,pos="-1.442,-1.799"]
Smoking [pos="-1.824,1.239"]
"Marital status" -> "Night Shifts"
"Marital status" -> "Physical activity"
"Marital status" -> Alcohol
"Marital status" -> BMI
"Marital status" -> Depression
"Marital status" -> Smoking
"Night Shifts" -> "Physical activity"
"Night Shifts" -> "Sleep quality"
"Night Shifts" -> Alcohol
"Night Shifts" -> BMI
"Night Shifts" -> Depression
"Night Shifts" -> Smoking
"Physical activity" -> "Sleep quality"
"Physical activity" -> Depression
"Physical activity" <-> BMI
"Sleep quality" <-> Alcohol
Age -> "Marital status"
Age -> "Night Shifts"
Age -> "Physical activity"
Age -> "Sleep quality"
Age -> Alcohol
Age -> Chronotype
Age -> Depression
Age -> Education
Age -> Smoking
Alcohol -> BMI
Alcohol <-> Depression
Alcohol <-> Smoking
BMI -> "Sleep quality"
BMI <-> Depression
Center -> "Marital status"
Center -> "Physical activity"
Center -> Alcohol
Center -> BMI
Center -> Depression
Center -> Education
Center -> Smoking
Chronotype -> "Night Shifts"
Chronotype -> "Physical activity"
Chronotype -> "Sleep quality"
Chronotype -> Alcohol
Chronotype -> BMI
Chronotype -> Depression
Chronotype -> Smoking
Depression -> "Sleep quality"
Depression <-> Smoking
Education -> "Marital status"
Education -> "Night Shifts"
Education -> "Physical activity"
Education -> BMI
Education -> Depression
Sex -> "Night Shifts"
Sex -> "Physical activity"
Sex -> "Sleep quality"
Sex -> Alcohol
Sex -> Chronotype
Sex -> Depression
Sex -> Education
Sex -> Smoking
Smoking -> "Physical activity"
Smoking -> "Sleep quality"
Smoking -> BMI
}
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