Table 1.
Overview of network studies on depression (N = 56).
| Comorbidity* (N = 23) | |||||
|---|---|---|---|---|---|
| Authors, year (reference) | N | Time-scale | Cross/dyn | Population | Bridge symptoms |
| Afzali et al., 2017 (20) | 909 | Macro | Cross | PTSD and depression screening | Sense of foreshortened future, guilt, sadness |
| An et al., 2019 (21) | 776 | Macro | Cross | MDD diagnosis and high/low anxiety (BAI ≥ 16 Or BAI <16) | No bridge symptoms identified |
| Beard et al., 2016 (22) | 742 | Macro | Cross | MDD, bipolar disorder, anxiety disorder, personality disorder and/or psychotic disorder diagnosis | No bridge symptoms identified |
| Bekhuis et al., 2016 (23) | 2,704 | Macro | Cross | MDD or GAD diagnosis now or in remission and healthy controls | Anxiety, fatigue, psychomotor agitation |
| Curtiss and Klemanski, 2016 (24) | 111 | Macro | Cross | MDD or GAD diagnosis | No bridge symptoms identified |
| de Haan et al., 2020 (25) | 2,313 | Macro | Cross | PTSD screening and depressive symptoms | Bridge estimates too unstable |
| de la Torre-Luque and Essau, 2019 (26) | 1,494 | Macro | Cross | MDD and social phobia diagnosis | No bridge symptoms identified |
| Djelantik et al., 2020 (27) | 458 | Macro | Cross | PGD, PTSD or MDD symptoms | No bridge symptoms identified |
| Garabiles et al., 2019 (28) | 355 | Macro | Cross | PHQ-9 ≥ 6 and GAD-7 ≥ 7 | Fatigue, sadness, anhedonia |
| Heeren et al., 2018 (29) | 174 | Macro | Cross | Social anxiety disorder diagnosis and (some) MDD diagnosis | Avoidance, fear of working while observed, suicidal ideation, anhedonia |
| Jones et al., 2018 (30) | 87 | Macro | Cross | OCD diagnosis and (some) MDD diagnosis | Obsessional problems, concentration, guilt, and sadness |
| Lazarov et al., 2020 (31) | 1,795 | Macro | Cross | PTSD diagnosis and depression screening | Sleep, sadness, tension, avoidance, upset due to trauma reminders |
| Levinson et al., 2017 (32) | 196 | Macro | Cross | Bulimia Nervosa and (some) MDD or anxiety diagnosis | No bridge symptoms identified |
| Lorimer et al., 2020 (33) | 867 | Macro | Cross | Relapse: PHQ-9 ≥ 10 and GAD-7 ≥ 8 Remission: PHQ-9 ≤ 10 and GAD-7 ≤ 8 | No bridge symptoms identified |
| McNally et al., 2017 (34) | 408 | Macro | Cross | OCD diagnosis and (some) MDD diagnosis | No bridge symptoms identified |
| Park and Kim, 2020 (35) | 223 | Macro | Cross | MDD diagnosis and anxiety symptoms | No bridge symptoms identified |
| Rogers et al., 2019 (36) | 167 | Macro | Cross | MDD, substance use, PTSD or bipolar disorder diagnosis | No bridge symptoms identified |
| Shim et al., 2020 (37) | 907 | Macro | Cross | MDD and AUD screening | Men: sadness, suicidal ideation, attempt |
| Women: worthlessness, suicidal ideation | |||||
| Tundo et al., 2020 (38) | 241 | Macro | Cross | MDD or bipolar disorder diagnosis and anxiety symptoms | No bridge symptoms identified |
| van Heijst et al., 2020 (39) | 618 | Macro | Cross | MDD, dysthymia or depressive disorder not otherwise specified diagnosis and autism symptoms | No bridge symptoms identified |
| Wang et al., 2020 (40) | 2,542 | Macro | Cross | PHQ-9 ≥ 5 and GAD-7 ≥ 5 | During outbreak**: psychomotor symptoms |
| After peak phase: irritability, energy loss | |||||
| Kaiser and Laireiter, 2018 (41) | 10 | Macro | Dyn-C | MDD, social anxiety disorder, or GAD or a combination | Large individual differences in bridge symptoms |
| Groen et al., 2020 (42) | 220 | Micro | Dyn-T | MDD and anxiety disorder | No evidence for bridge symptoms |
| Centrality (N = 30) | |||||
| Authors, year (reference) | N | Time-scale | Cross/dyn | Population | Most central in network |
| Berlim et al., 2020 (43) | 151 | Macro | Cross | MDD diagnosis | Before AD: fatigue, cognitive disturbance, suicidality |
| After AD: sadness, psychomotor disturbance, cognitive disturbance | |||||
| Bos et al., 2018 (44) | 178 | Macro | Cross | MDD diagnosis | Before AD: energy loss, concentration, worthlessness |
| After AD: anhedonia, worthlessness | |||||
| Boschloo et al., 2016 (45) | 501 | Macro | Cross | Future MDD diagnosis | Energy loss, concentration, anhedonia |
| Carney et al., 2018 (46) | 125 | Macro | Cross | MDD diagnosis | In remission: energy loss, hypersomnia, concentration |
| Not in remission: fatigue, energy loss, hypersomnia | |||||
| de la Torre-Luque et al., 2020 (47) | 427 | Macro | Cross | MDD diagnosis | Concentration, energy loss, slow thinking |
| Fried et al., 2016 (48) | 3,463 | Macro | Cross | MDD diagnosis | Energy loss, anhedonia, appetite |
| Hakulinen et al., 2020 (49) | 595 | Macro | Cross | MDD diagnosis | Anhedonia, sadness, energy loss |
| Kendler et al., 2018 (50) | 5,952 | Macro | Cross | MDD diagnosis | Psychomotor skills, hopelessness, reduced self-confidence |
| Madhoo and Levine, 2016 (51) | 2,876 | Macro | Cross | MDD diagnosis | Before AD: hypersomnia |
| After AD: sadness | |||||
| Murri et al., 2018 (52) | 8,557 | Macro | Cross | EURO-D ≥ 1 | Suicidality, anhedonia, sadness |
| Park et al., 2020 (53) | 1,174 | Macro | Cross | MDD diagnosis | Sadness, fatigue, anhedonia |
| Santos et al., 2017 (54) | 515 | Macro | Cross | BDI ≥ 10 and healthy controls | Sadness, joy |
| Santos et al., 2018 (55) | 306 | Macro | Cross | CES-D ≥ 16 | Feeling unwanted, concentration |
| Semino et al., 2017 (56) | 264 | Macro | Cross | GDS > 5 | Full of energy, hopeless, happy |
| van Borkulo et al., 2014 (57) | 1,108 | Macro | Cross | MDD diagnosis now or in remission and healthy controls | Sadness, energy loss, self-criticism |
| van Borkulo et al., 2015 (58) | 515 | Macro | Cross | MDD diagnosis | Anhedonia, energy loss, concentration |
| van Loo et al., 2018 (18) | 5,784 | Macro | Cross | MDD diagnosis | Psychomotor skills, hopelessness, decreased self-confidence |
| Bringmann et al., 2015 (59) | 182 | Macro | Dyn-T | MDD diagnosis | Out: suicidality and anhedonia |
| In: indecision and anhedonia | |||||
| Groen et al., 2019 (60) | 60 | Macro | Dyn-T | MDD diagnosis | Out: worrying and energy loss |
| In: feeling trapped and energy loss | |||||
| Komulainen et al., 2020 (61) | 3,559 | Macro | Dyn-T | MDD diagnosis | AD Out: Suicidality, work/activity difficulties, weight loss In: Insight, suicidality, work/activity difficulties |
| Placebo Out: Insight, suicidality, retardation In: Insight, retardation, genital symptoms | |||||
| Savelieva et al., 2020 (62) | 72,971 | Macro | Dyn-T | EURO-D≥1 | Out: suicidality, fatigue, sadness |
| In: suicidality, anhedonia, sadness | |||||
| Bos et al., 2017 (9) | 104 | Micro | Cross | MDD diagnosis | Worry and self-doubt |
| Bos et al., 2017 (9) | 104 | Micro | Dyn-C | MDD diagnosis | Sadness and restlessness |
| Bos et al., 2017 (9) | 104 | Micro | Dyn-T | MDD diagnosis | Out: cheerful | In: sadness |
| David et al., 2018 (63) | 1 | Micro | Dyn-T | MDD diagnosis | Out: tension | In: concentration |
| de Vos et al., 2017 (64) | 54 | Micro | Dyn-T | MDD diagnosis | Out: cheerful | In: tense |
| Fisher et al., 2017 (65) | 1 | Micro | Dyn-C | MDD diagnosis | Hopeless and guilty |
| Fisher et al., 2017 (65) | 1 | Micro | Dyn-T | MDD diagnosis | Out: positivity | In: content |
| Wichers et al., 2016 (66) | 1 | Micro | Dyn-T | MDD diagnosis in remission | Positive affect |
| Wigman et al., 2015 (67) | 129 | Micro | Dyn-T | MDD diagnosis | Out: cheerful | In: content |
| Connectivity (N = 17) | |||||
| Authors, year (reference) | N | Time-scale | Cross/dyn | Population | Hypothesis connectivity |
| Baez and Heller, 2020 (68) | 3,184 | Macro | Cross | MDD diagnosis | Higher connectivity for younger ages of onset |
| Berlim et al., 2020 (43) | 151 | Macro | Cross | MDD diagnosis | No support |
| Bos et al., 2018 (44) | 178 | Macro | Cross | MDD diagnosis | No support |
| Hakulinen et al., 2020 (49) | 6,593 | Macro | Cross | MDD diagnosis and healthy controls | No support |
| Madhoo and Levine, 2016 (51) | 2,876 | Macro | Cross | MDD diagnosis | Supports hypothesis |
| Santos et al., 2017 (54) | 515 | Macro | Cross | ≥10 BDI and healthy controls | Supports hypothesis |
| Schweren et al., 2018 (69) | 465 | Macro | Cross | MDD diagnosis | No support |
| van Borkulo et al., 2015 (58) | 515 | Macro | Cross | MDD diagnosis | Supports hypothesis |
| Groen et al., 2019 (60) | 60 | Macro | Dyn-T | MDD diagnosis | No support |
| de Vos et al., 2017 (64) | 54 | Micro | Dyn-T | MDD diagnosis | Supports hypothesis depending on method |
| Pe et al., 2015 (70) | 106 | Micro | Dyn-T | MDD diagnosis | Supports hypothesis |
| Snippe et al., 2017 (71) | 169 | Micro | Dyn-T | MDD diagnosis | No support |
| van de Leemput et al., 2014 (72) | 93 | Micro | Dyn-C | MDD diagnosis | No support |
| van de Leemput et al., 2014 (72) | 621 | Micro | Dyn-C | Future increase in SCL-90 depressive symptoms | Supports hypothesis |
| Wichers et al., 2016 (66) | 1 | Micro | Dyn-T | MDD diagnosis in remission | Supports hypothesis |
| Wichers et al., 2020 (73) | 6 | Micro | Dyn-T | MDD diagnosis in remission | Supports hypothesis |
| Wigman et al., 2015 (67) | 129 | Micro | Dyn-T | MDD diagnosis | Supports hypothesis |
Overviews are given for the studies on comorbidity (upper panel), centrality (middle panel), and connectivity (lower panel), respectively. Findings of studies that have constructed multiple networks are given separate rows to distinguish their findings.
“And” denotes populations consisting of individuals with both diagnoses or symptom types; “Or” indicates populations consisting of individuals with either one of the diagnoses or symptom types.
*
For the category comorbidity, inclusion criteria were broadened to also include studies with additional participants who experience other sorts of psychiatric symptoms than depressive symptoms (only).
**
Refers to the COVID-19 outbreak.
AD, use of antidepressants; AUD, alcohol use disorder; BAI, Beck Anxiety Inventory; BDI, Beck Depression Inventory; CES-D, Center for Epidemiological Studies Depression; Cross, cross sectional associations; Dyn-C, dynamic contemporaneous associations; Dyn-T, dynamic temporal associations; GAD, generalized anxiety disorder; GDS, Geriatric Depression Scale; In, incoming centrality; MADRS, Montgomery-Åsberg Depression Rating Scale; OCD, obsessive compulsive disorder; PGD, prolonged grief disorder, PHQ-9, Patient Health Questionnaire; PTSD, posttraumatic stress disorder; Out, outgoing centrality.