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. 2022 Feb 3;6(Suppl 7):2–63. doi: 10.25646/9537

Annex Table 3 Publication.

Category I: Primary data

Abbreviations used:

M = median, SD = standard deviation, cut-off = fixed limit of an instrument from which a certain interpretation of the results applies, n = sample size, N = full survey, OP = observation period, CP = comparison period, t1 = measurement time 1, t2 = measurement time 2., difference = calculation of the intra-individual deviation of different measurement times

STUDY TYPE A: Representative cross-sectional studies in trend design with random sampling from the general population and identical survey design of the temporal comparative data [1–16]
Study or data basis and publications (including observation period etc.) Results
Outcome Operationalisation/measuring instrument Description and interpretation by authors of the publication
Data basis: SOEP-CoV

Survey study (telephone): special study with two survey waves of the Socio-Economic Panel (SOEP) based on offline random sampling (households of the general population, persons aged 18-over 80); comparison over time between the samples and additionally with identically surveyed outcomes in previous years’ SOEP surveys.

First wave: 31.03.–04.07.2020; second wave: 01.01.–28.02.2021

[1] Entringer T, Krieger M (2020): OP: 01.04.–30.06.2020 (n=5,529, division into three pandemic phases)

[2] Entringer T, Kröger H (2020): OP: 01.04.– 26.4.2020 (n=3,599)

[3] Entringer T, Kröger H, Schupp J et al. (2020): OP: 01.04.–26.04.2020 (n=3,599)

[4] Kritikos AS, Graeber D, Seebauer J (2020): OP: 01.04.–24.05.2020 (n=3,052)

[5] Liebig S, Buchinger L, Entringer T et al. (2020): OP: 01.04.–04./05.07.2020 (n=5,617)

[6] Seebauer J, Kritikos AS, Graeber D (2021): OP: 01.04.–04./05.07.2020 versus CP 2019 (n=5,617)

[14] Entringer T, Kröger H (2021): OP: 01.01.–28.02.2021 versus CP: 31.03.–04.07.2020 or previous years (n=6,013)

[13] Entringer T, Kröger H (2021): OP: 01.01.–28.02.2021 versus CP: 31.03.2020–04.07.2020 or previous years (n=6,013)		 a Satisfaction of life

compared to 2015–2019		 Short scale L-1 (Scale 0–10) Unchanged in general population until 30.06.2020 at 7.44 similar to previous year [2]; reduction at the beginning of 2021 to 7.2 [13, 14]

Reduction among self-employed [4]; especially reduction among women [5] also in further course of the pandemic [13, 14]

Increase for single people; unchanged among couples without children and single parents; reduction for couples with children [1]

Increase among people with low income, low education; decrease among people with high income, high education – reduction of socioeconomic differences [3], is also evident as the pandemic continues [13]
a Wellbeing

compared to 2007–2019		 Four single items (Scale 1–5) Unchanged in general population [2, 3, 5]: 14.7 in 2020, similar to previous year. Small and not significant reduction to 14.5 in 2021 [13, 14]

Increase for single people; unchanged among couples without children and single parents; reduction for couples with children [1]
c Depressive and anxiety symptoms

compared to 2016, 2019		 PHQ-4

(M, Scale 1–12)		 Increase in general population compared to 2019; however, unchanged compared to 2016 [2, 3, 5]. In the OP 01.04–30.06.2020, the value is 2.4 [2, 3, 5] and in the OP 01.01–28.02.2021, the value is 2.2 [13, 14]. In 2019 it was 1.9 and in 2016 it was 2.3

Increase of incidence of depressive symptoms in general population compared to 2019: 21% depressive symptoms not present at any time in OP vs. 38% in CP [6]

Particularly affected by an increase are people with a migration background [3, 13, 14], women and younger people [13, 14]; longitudinally, the situation worsened considerably for female self-employed workers [6]
Data basis: Mannheim Corona Study

Survey study (online): special study of the German Internet Panel (GIP) based on offline random sampling: repeated weekly survey of approx. 3,600 people aged 18–75 in each case in the period 20.03.–09.07.2020, daily survey of an average of 489 people; comparison over time by showing weekly progression

[7] Mata J, Wenz A, Rettig T et al. (2020): OP: 20.03.–09.07.2020

[8] Blom A G, Wenz A, Rettig T et al. (2020): OP: 20.03.–09.07.2020

[9] Naumann E, Mata J, Reifenscheid M et al. (2020): OP: 20.03.–16.04.2020		 b Anxiety State-Trait Anxiety Inventory short scale

Until week 4: Five items (M; cut-off >2) [9]

from week 5: Two items [7, 8]		 Decrease of the initially increased level of anxiety in the general population already during the first lockdown from 20 March to 16 April to 1.9 [9], in the further course of the pandemic until July stable, very slightly decreasing level to 1.70 and 1.66 respectively (taken from graphical representation) [7, 8]

Decline in all population groups, strongest among young people [9]
c Depressive symptoms from week 5: PHQ-2 Decrease in general population over the course of the pandemic [7] from 1.50 to 1.43 (from graphical representation) in all population groups, no increase in vulnerable groups
Data basis: GEDA-EHIS 2019/2020

Survey study (telephone) of the European Health Interview Survey (EHIS) for Germany in the general population aged 15-over 80 (n=23,001, approx. 1,300 persons per month); comparison over the time before, during and after the lockdown in Germany (from 16.03.2020) within the surveyed study sample and presentation of monthly progression

[11] Damerow S, Rommel A, Prütz F et al. (2020): OP: 04/2010–09/2020 (n=23,001) versus CP: 04/2019–03/2020

[15] Cohrdes C, Yenikent S, Wu J et al. (2021): OP: 01.01.–30.06.2020 versus CP: CW 1–11 2020, CW 12–18 2020, CW 19–31 2020 (n=9,011)		 c Depressive symptoms PHQ-8 (>9) Unchanged in general population [11] 6.6% of population in CW 15–26 2020 compared to 8.3% CW 15–26 2019.
c Individual symptoms PHQ-8 over time Decrease of two symptoms in general population (lack of energy; concentration problems) [11] 18.1% of population report concentration problems (CW 15–26 vs. 21.9% CW 15–26 2019) [11] and 50.7% of population report lack of energy (CW 15–26 vs. 64.0% CW 15–26 2019) [11]

Decrease in lack of energy in general population during CW 12–18 2020 (first lockdown) compared to CW 1–11 2020, subsequent increase in CW 19–31 2020 to level of CW 1–11 2020 [15]
Data basis: Study of Ulm University

Survey study (personal interview) using the random route method in the general population aged 14–95; temporal comparison of the sample surveyed before and after the lockdown in Germany (from 16.03.2020)

[12] Sachser C, Olaru G, Pfeiffer E et al. (2021): OP: 10.02.–15.03.2020 versus CP 16.03.–25.04.2020 (n=2,503)		 c Psychopathological symptoms Brief Symptom Inventory (BSI-18) Decrease in general population from M=3.73; SD=6.39 compared to M=5.00; SD=7.93 in the CP [12]

Unchanged in OP compared to CP for older people and people with low income
Data basis: Study of the Universities of Mainz and Leipzig

Survey study (personal interview) using the random route method in the general population aged 14–95; temporal comparison with analogue study conducted in 2018

[16] Beutel ME, Hettich N, Ernst M et al. (2021): OP: 02.05.–29.06.2020 (n=2,503) compared to CP: May–July 2018 (n=2,516)		 c Depressive and anxiety symptoms PHQ-4 (M) Increase of depressive symptoms to M=1.14; SD=1.23 compared to M=0.89; SD=1.21 in the CP [16]

Increase of anxiety symptoms to M=1.05; SD=1.31 compared to M=0.77; SD=1.17 in the CP [16]
Data basis: Regional Study of the Central Institute of Mental Health Mannheim

Survey study (written) in the Mannheim area in the general population aged 18–65; comparison over time with study from 2018 with the same survey design

[10] Kuehner C, Schultz K, Gass P et al. (2020): OP: 24.04.–23.05.2020 compared to CP 2018 (n=721)		 a Wellbeing WHO-5-Well-Being-Index Unchanged in general population to 2018 (2020: M=56.52; 2018: M=56.83) [10]
b Psychosocial distress PHQ-D Stress Module (total) Unchanged in general population compared to 2018 [10]
c Symptoms and syndrome diagnosis: Depressive disorder, anxiety disorder, Somato-form disorder Comorbidity syndrome diagnosis. Screening-based syndrome diagnoses from PHQ-D

Sum values of the respective symptoms		 Unchanged in general population (Mannheim region) in OP versus CP (PHQ-D syndrome diagnosis 2020: 29.4%; 2018: 26.8%; PHQ-D comorbidity diagnosis 2020: 20.3%; 2018: 8.9%) [10]
STUDY TYPE B: Representative cross-sectional studies in trend design with random sampling from an access panel and identical survey design of the temporal comparative data [17–21]
Study or data basis and publications (including observation period etc.) Results
Outcome Operationalisation/measuring instrument Description and interpretation by authors of the publication
Data basis: COSMO – COVID-19 Snapshot Monitoring

Survey study (online): weekly each approx. 1,000 persons aged 18–74 years since 03.03.2020 with random drawing via a panel provider. A representative distribution of the data by age × gender as well as federal state is aimed for. Education is not taken into account. Comparison over time by presenting the weekly course, partly additional comparison with previous norm data.

[21] COSMO – COVID-19 Snapshot Monitoring: Resilience (2021): OP: until 01.06.2021

[20] COSMO – COVID-19 Snapshot Monitoring: Resources and stresses (2021): OP: until 14.07.2021

[19] Gilan D, Röthke N, Blessin M et al. (2020): OP: t1: 24.03.2020, t2: 31.03.2020, t3: 21.04.2020 each compared with norm sample		 a Satisfaction of life – information until 14.07.2021 Single item (Scale 1–7) Unchanged in general population and stable over the course of the pandemic (until 14.07.2021): M=4.6 to M=4.8 [20]
b Situational stress – information until 14.07.2021 Single item High burden in general population at the beginning of the pandemic (52% burdened) – decline to 33% in September 2020, since then increase to peak of 61% in early February 2021, decline since early May 2021 to approximately the level of summer 2020 [20]

Increase in all age groups since September 2020, especially in the 18–29 age group (69% burdened in January and April 2021); decrease since May 2021 [20]
b Mental distress (anxiety, dejection) – information until 09.03.2021 Five single items from GAD-7, ADS, IES-R (M) Increase in anxiety in general population at onset of pandemic (24.03.2020: M=0.77; SD=0.94 and 31.03.2020: M=0.75; SD=0.91) compared to norm sample (M=0.50; SD=0.64), decline until end of April 2020 (M=0.60; SD=0.83) [19], then level relatively unchanged until 09.03.2021 [20]

Increase in dejection in the general population at the beginning of the pandemic (M=0.66; SD=0.88) compared to the norm sample (M=0.43; SD=0.70), level unchanged until April 2020 [19], increase in younger people until 09.03.2021 [20]

Risk factors for high psychological stress: young age, female gender, having children, single parent, migration background, living alone or more than two persons in household [19]
a Resilience – Information until 14.07.2021 Brief-Resilience-Scale (BRS) Unchanged in general population at start of pandemic (M=3.45; SD=0.85) compared to norm sample 2018 (M=3.49; SD=0.84) [19, 21], decrease over course of pandemic [21] (24.03.2020: M=3.43 compared to 01.06.2021: M=3.25)

Older people more resilient than younger people, older people more resilient during the pandemic also compared to the 2018 norm sample [21]
Data basis: German-Depression-Barometer

Survey study (online): COVID-19 focus conducted twice since the beginning of the pandemic in general population aged 18–69 years; based on RESPONDI panel; comparison over the time of the two observation periods

[18] Stiftung Deutsche Depressionshilfe 2020 (2020): OP: 06/2020 + 07/2020 (n=5,178)

[17] Stiftung Deutsche Depressionshilfe 2021 (2021): OP: 02/2021 (n=5,135)		 b Mental distress Single items Increase in the feeling of low mood in the general population(71% perceive second lockdown as depressing compared to 59% in the first lockdown compared to 36% in summer 2020) [17, 18]

Increase in severe family stress in the general population (25% in the second lockdown compared to 16% in summer 2020) [17]

Increase in general population’s perception that fellow citizens are inconsiderate (second lockdown 46% vs. first lockdown 40%) [17]
STUDY TYPE C: Representative, one-off cross-sectional studies with random drawing without an identical survey design of the temporal comparative data [22–25]
Study or data basis and publications (including observation period etc.) Results
Outcome Operationalisation/measuring instrument Description and interpretation by authors of the publication
Data basis: Corona-COMPASS-Study

Survey study (online) with a random sample from a commercial panel (payback panel, no possibility for participants to self-select); eligible population with online access aged 18–70 (n=8,977, of which 5,844 were interviewed twice), comparison over time with previous SOEP surveys (see study type A)

[24] Huebener M, Waights S, Spiess K et al. (2020): OP: 01.05.–01.07.2020 versus CP 2018 (n=8,977)		 a Satisfaction of life Short scale L-1 (Scale 0–10) Decrease in general population compared to 2018: M=6.95 compared to M=7.36 [24]

Decrease among parents with children younger than 16 years, women and people with low education; highest life satisfaction among older persons (>65 years) [24]
Data basis: Parent Study of the Berlin University Alliance

Survey study (telephone, online) of parents of minor children aged 18–73 years, random sample of Germanspeaking households with minor children; comparison over time with previous norm samples and retrospective self-assessment.

[23] Calvano C, Engelke L, Di Bella J et al. (2021):
Survey from 03.08.11.08.2020; (n=1,024) plus erratum [25]		 b Stress experience Parental Stress Scale (total) for time of subjectively highest stress (OP) and for January 2020 (CP) Increase in general population (parents of minor children) at time of highest exposure so far during pandemic versus retrospective estimate for January 2020: M=36.93; SD=10.45 compared to pre-COVID-19 M=34.72; SD=10.63 [23]
c Depressive and anxiety symptoms PHQ-4 (M) for time of subjectively highest stress (OP) Increase in general population (parents of minor children) at time of highest stress compared to pre-pandemic norm sample; depressive symptoms:
M=1.38 in the OP compared to M=0.94 in the CP; symptoms of anxiety:
M=1.14 in the OP compared to M=0.82 in the CP [23, 25]
Data basis: Study of the elderly population aged 65 and over by the University of Leipzig

Survey study (telephone), random sample of older people aged 65–94 in the general population; comparison over time with previous norm samples.

[22] Röhr S, Reininghaus U, Riedel-Heller S G (2020): OP 06.04.–25.04.2020		 c Psychopathological symptoms Brief Symptom Inventory (BSI-18) Unchanged in general population (persons 65 years and older) compared to pre-pandemic norm levels (M: 1.4 vs. 2.0; 1.6 vs. 1.6; 2.2 vs. 2.4 and 5.1 vs. 6.0) [22]
STUDY TYPE D: Cohort studies with representative initial sample and random sampling at t1 [26, 27]
Study or data basis and publications (including observation period etc.) Results
Outcome Operationalisation/measuring instrument Description and interpretation by authors of the publication
Data basis: NAKO Health Study

Survey study (online): special longitudinal survey of the NAKO Health Study; baseline survey t1 as random sample from 18 study regions (2014–2019, n=205,219); comparison over time with t2: re-participants at t2 aged 20–74 years (n=113,928, approx. 55% of t1, no difference in re-participation by age, gender, lower in north-eastern study sites).

[26] Peters A, Rospleszcz S, Greiser K H et al (2020): OP: 30.04.–29.05.2020 (n=113,928) versus CP (t1: 2014–2019)

[27] Berger K, Riedel-Heller S, Pabst A et al. (2021): OP: 30.04.–29.05.2020 (n=113,928) versus CP (t1: 2014–2019)		 c Depressive symptoms PHQ-9 Cut-Off: >9

Total; mean difference to t1		 Increase in the general population (in the study sites) to 8.8% (t2) compared to 6.4% (t1) and by an average of 0.3 compared to CP [27].

Increase is only seen in persons under 60 years of age in the mean difference of 0.38+/-0.02 points [26]; clearest increase in youngest age group; stronger in regions with higher incidence and in persons tested positive for COVID-19 [26]
c Symptoms of generalised anxiety disorder GAD-7 Cut-Off: >9

Total; mean difference to t1		 Increase in the general population (in the study sites) to 5.7% (t2) compared to 4.3% (t1) and 0.45 for women and for men 0.2 [27]

Increase is only seen in persons under 60 years of age in the mean difference of 0.38+/-0.02 points [26]; clearest increase in youngest age group; stronger in regions with higher incidence and in persons tested positive for COVID-19 [26]
b Psychosocial stress burden PHQ-D stress module

Total; mean difference at t1		 Increase in the general population (in the study sites) in the mean difference by 0.36+/-0.02 points in all age groups [26]

Increase stronger in regions with higher incidence and in individuals who tested positive for COVID-19 [26]
STUDY TYPE E: Longitudinal studies with non-probability initial sample at t1 [28–32]
Study or data basis and publications (including observation period etc.) Results
Outcome Operationalisation/measuring instrument Description and interpretation by authors of the publication
Data basis: LORA – Longitudinal Resilience Assessment

Survey study (online) as a special survey of the LORA study (=prospective study of healthy adults with a focus on resilience, Rhine-Main region): since 31.03.2020 with the start of the first lockdown in Germany, implementation of eight weekly surveys; participants aged 18–50 years (M=31.5±8.4), 69% female without differences to the LORA initial sample; comparison over the time during the pandemic and compared to the last measurement before the outbreak event

[29, 32] Ahrens KF, Neumann RJ, Kollmann B et al. (2021): OP: from 31.03. through eight weekly surveys (t1: n=523, t8: n=451) compared to CP: last measurement before pandemic		 b Everyday burdens per week Amount Decrease in sample to [32] to 41.2±22.3 in week 8 versus 60.0±27.2 before the pandemic [29]
c Mental symptoms GHQ-28 Difference, M Average decrease [32] in sample to 16.2±7.1 in weeks 5 to 8 versus 20.5±9.7 before the pandemic [29]

Identification of three subgroups when analysing intra-individual changes: continuous increase in psychological symptoms at around 8%; at 9% initial increase and rapid decrease; at 83% improvement or unchanged from pre-pandemic levels [29, 32]
Data basis: Longitudinal study (project to classify the factorial structure of protective factors influencing health at Saarland University)

Survey study (online), sampling from self-recruiting WiSo panel (sampling procedure not documented in publication); participants aged 20–95 years (M=55.0; SD=13.9), 53.6% female; comparison over time between t1 (before pandemic outbreak) and t2.

[31] Schäfer S K, Sopp M R, Schanz C G et al. (2020): t1: 17.02.–23.02.2020, t2: 16.03.–22.03.2020; n=1,591		 c Psychopathological symptoms Mini-Symptom Checklist Difference Unchanged in entire group (i.e. on average without taking individual change into account).

Intra-individual increase at about 10%, decrease at about 8%, unchanged for about 82% of the sample from t1 to t2 [31]
Data basis: Longitudinal study with adults working fulltime

Survey study (mode not stated); sample from representative online panel: full-time working adults aged 18–69; 59.6% female; comparison over time using four survey time points with t1 before pandemic

[30] Zacher H, Rudolph C W (2020): OP: t1: 12/2019, t2: 03/2020; t3: 04/2020, t4: 05/2020 (n=979)		 a General satisfaction of life Single item (Scale 1 to 7) Intra-individual decrease in general satisfaction of life between March and May 2020, no change between December 2019 and March 2020 [30]
a Wellbeing Items of the Positive and Negative Affect Schedule (Short Form) Intra-individual decrease of positive and negative affect between March and May 2020, no change between December 2019 and March 2020 [30]
Data basis: CORA – Longitudinal Study of the Charité Berlin

Survey study (online), pandemic-initiated with self-selecting baseline sample at t1 in general population and three follow-up surveys; inclusion with participation in at least one follow-up survey (n=2,376 people (age 18–82) were willing to be interviewed again [see 33]) selective sample with 76.7% female; 89.6% higher education or health workers; Temporal comparison over time over the course of the pandemic

[28] Bendau A, Plag J, Kunas S et al. (2020): OP: 27.03.–15.06.2020 (t1: 03/2020, t2: 04/2020, t3: 05/2020, t4: 06/ 2020)		 c Depressive and anxiety symptoms PHQ-4 (Cut-Off >5); M, Median, Difference Decrease in sample from 31.0% (t1) to 22.6% (t4) [28]

Continuous decrease in the mean value of the sample across all measurement points; especially decrease in symptom severity; decrease in the median value from 4 (t1) to 3 (t4) [28]

Intra-individual increase in about 25% of the sample from t1 to t4 [28]
c Depressive symptoms PHQ-2 (Cut-Off >2); M, Median, Difference Decrease in sample from 32.7% (t1) to 25.3% (t4) [28]

Continuous decrease in the mean value of the sample across all measurement points; especially decrease in symptom severity; no decrease in the median value [28]

Intra-individual increase in about 25% of the sample from t1 to t4 [28]
c Symptoms of generalised anxiety disorder GAD-2 (Cut-Off >2); M, Median, Difference Decrease in sample from 36.4% (t1) to 24.9% (t4) [28]

Continuous decrease in the mean value of the sample across all measurement points; especially decrease in symptom severity; decrease in the median value from 2 (t1) to 1 (t4) [28]

Intra-individual increase in about 10% of the sample from t1 to t4 [28]
b COVID-19-related anxiety C-19-A M, Median, Difference Continuous decrease in the mean value of the sample across all measurement points; decrease in the median value from 9 (t1) to 4 (t4) [28]

Intra-individual increase in about 10% of the sample from t1 to t4 [28]
STUDY TYPE F: Cross-sectional studies with online non-probability sample [33–45]
Study or data basis and publications (including observation period etc.) Results
Outcome Operationalisation/measuring instrument Description and interpretation by authors of the publication
Data basis: Online survey of the LVR-Klinikum Essen

Cross-sectional survey 1 (10.03.–27.07.2020): Sample composition differs from the general population at all evaluation points (approx: 70% female, 75% with high education (at least Abitur), 61% younger than 44 years). Standardisation by calculation of weighting factors for the distribution of characteristics in the general population is not described.

Since the second wave of infection, the study has been continued as a new cross-sectional study.

[34] Moradian S, Bäuerle A, Schweda A et al. (2021): OP: 15.03.–04.04.2020 versus CP: 02.11–22.11.2020; adjustment of the two samples has been conducted (n=7,288)

[35] Bäuerle A, Steinbach J, Schweda A et al. (2020): OP: 10.03.–05.05.2020; temporal comparison with retrospective assessment of the same instrument before the pandemic (n=15,037)

[36] Bäuerle A, Teufel M, Musche, V et al. (2020): OP: 10.03.–05.05.2020 compared to norm sample, adjustment of samples not described (n=15,037)

[37] Hetkamp M, Schweda A, Bäuerle A et al. (2020): OP: 10.03.–30.04.2020; comparison over time in the pandemic and against CP: norm sample, adjustment of samples not described (n=16,245)

[38] Skoda EM, Spura A, De Bock F et al. (2021): OP: 10.03.–27.07.2020; comparison over time with norm sample before the pandemic and during the pandemic by dividing into five pandemic phases (n=16,918)		 c Depressive symptoms PHQ-2 (Cut-Off >2), M 14.3% (OP) in sample vs. 7.6% (CP: retrospective assessment of instrument before pandemic); mean difference significant; interpreted as increase, especially among persons with pre-existing mental disorder [35]

14.3% (OP) in sample versus 5.6% (CP: norm sample); interpreted as increase [36]

Lockdown 2 > Lockdown 1 in samples; interpreted as increase [34]

Increase in sample from 8% in initial phase to 17% during phase 2 and 21% during phase 3 (crisis, lockdown), stable level afterwards; plus increase compared to 5.6% in pre-COVID-sample [38]
c Symptoms of generalised anxiety disorder GAD-2 (Cut-Off >2), M 19.7% (OP) in sample vs. 9.0% (CP: retrospective assessment of instrument before pandemic); mean difference significant; interpreted as increase [35]
c Symptoms of generalised anxiety disorder GAD-7 (Cut-Off >9, at least moderate symptoms) 16.8% (OP) in sample vs. ~ 6% (CP: norm sample); interpreted as increase [36]

Increase in the sample over the course of the pandemic from 7% to 37% to 22%. Comparison with norm sample interpreted as up to 8-fold increase in prevalence in population exposed to COVID-19 [37]

Increase in sample from 9% in initial phase to 22% each during phases 2 and 3 (crisis, lockdown), then slight drop to still higher level (22% and 20% respectively) compared to baseline values; plus increase in sample compared to norm sample of ~ 6%, interpreted as 2 to 10-fold increase in fear during pandemic [38]

Unchanged in samples during the pandemic: lockdown 1=lockdown 2 [34]
b Mental distress Distress Thermometer (Cut-Off >3) 65.2% (OP) in sample vs. 51.8% (CP: retrospective assessment of instrument before the pandemic); mean difference significant; interpreted as increase [35]

65.2% (OP) in sample vs. 39% (CP: norm sample); interpreted as increase [36]

Unchanged in samples during the pandemic: lockdown 1=lockdown 2 [34]

Increase in sample from 51% in initial phase to 63% during phase 2 and 60% during phase 3 (crisis, lockdown), then stable level of 58%; plus increase in sample compared to norm sample with 39% [38]
b COVID-19 related anxiety Single item (Scale 1–7) Increase in sample at the beginning of the pandemic, then decrease below baseline level [37, 38]
Data basis: CORA [see 28] Initial sample – Charité Berlin

Survey study (online; self-selecting) in general population 18 years and older; selective composition: 70.1% female; 82.4% higher education (at least university entrance qualification); comparison over time with norm sample before pandemic, adjustment of samples not described

[33] Petzold MB, Bendau A, Plag J et al. (2020): OP: 27.03.–06.04.2020 (n=6,509) versus CP: Publication from 2010		 c Depressive and anxiety symptoms PHQ-4, M 4.15 in sample vs. 1.76 in norm sample; interpreted as hypothesis-generating indication of possible increase [33]
Data basis: Initial sample of a longitudinal study of the University Tübingen

Survey (online; self-selecting) in general population aged 18–85 years with the aim of identifying protective factors for mental health; selective composition: 76.6% female; 81.4% higher education (at least university entrance qualification); comparison over time with representative pre-pandemic data without sample adjustment.

[39] Bauer LL, Seiffer B, Deinhart C et al. (2020): OP: 08.04.–26.04.2020 versus CP: representative data from 2013 (n=3,700)		 c Depressive symptoms PHQ-9 (>9,. at least moderate msymptoms) 31.4% in OP compared to 8.1% in CP; interpreted as an increase in the prevalence of depressive disorders [39]
c Symptoms of panic disorder PHQ-Panic Module Long Version 5.7% in OP vs. 2.0% in CP; interpreted as increase in the prevalence of panic disorders [39]
c Symptoms of generalised anxiety disorder GAD-7 (>9, less. moderate symptoms) 7.4% in OP compared to 2.2% in CP; interpreted as an increase in the prevalence of generalised anxiety disorders [39]
Data basis: Online survey of the Charité Berlin

Survey (online; self-selecting) in general population aged 18–81 years; 75.5% female; temporal comparison over the course of the pandemic (monthly)

[40] Liu S, Heinzel S, Haucke MN et al. (2020): OP: April–September 2020 (n=1,903)		 b COVID-19 related stress COVID-19 Peritraumatic Distress Index (CPDI) Increase of reported psychological distress in the sample over the survey period. Women, young people and lonely people were particularly affected [40]
Data basis: Online survey of the Medizinische Hochschule Hannover

Survey study (online; self-selecting) in general population aged: M=40.4; SD=11.7; 83% female (separate reporting for women and men); years of education: M=15.9; SD=4.2), comparison over time with norm samples, among others, adjustment of the sample not described

[41] Jung S, Kneer J, Krüger T (2020): OP: 01.04.–15.04.2020 (n=3,545)		 b Psychosocial stress burden PHQ Stress-Module Women 6.40 and men: 6.19 in sample – men and women are in the range of mild psychosocial stress (Defined range: 5–9) [41]
c Depressive and anxiety symptoms PHQ-4; (M) Women in the sample 3.91 vs. 1.71 in reference sample; men in the sample: 3.21 vs. 1.31 in reference sample; interpreted as mental distress [41]
a Wellbeing WHO-5 (M) Women 51.44 vs. 72.6 in reference sample (or: vs. healthy individuals who have an average score of 75); men: 47.52 vs. 68.28 in reference sample (or: vs. healthy individuals who have an average score of 75); interpreted as psychological distress [41]
Data basis: Initial sample of a longitudinal study of the Justus Liebig University Giessen

Survey study (online; self-selecting) in general population aged 18 years and older; selective composition: 79.5% female; 62.8% students; comparison over time with prevalences of mental disorders based on psychodiagnostic interview and representative data, adjustment of sample not described

[42] Munk AJL, Schmidt NM, Alexander N (2020): OP: 27.03.–03.04.2020 (n=949)		 c Symptoms ‘Any mental disorder’ All instruments listed here 50.6% vs. 27.9% 12-month prevalence in general population; interpreted as increase [42]
c Depressive symptoms Beck-Depression-Inventory 35.3% vs. 7.7% 12-month prevalence in general population; interpreted as increase [42]
c Symptoms of generalised anxiety disorder GAD-7 12.0% vs. 2.2% 12-month prevalence in general population; interpreted as increase [42]
c Symptoms of panic disorder PHQ-Panic module 5.4% vs. 2.0% 12-month prevalence in general population; interpreted as increase [42]
c Symptoms of obsessive compulsive disorder Obsessive-Compulsive Inventory-R 21.4% vs. 3.6% 12-month prevalence in general population; interpreted as increase [42]
Data basis: Online survey of the universities Marburg and Gießen

Survey study (online; self-selecting) in general population aged 18–81 years; 74.8% female; comparison over time using retrospective assessment of the same measure before the first lockdown

[43] Schwinger M, Trautner M, Kärchner H et al. (2020): OP: 01.04–28.05.2020 (n=1,086)		 a General satisfaction of life Four Items of the Temporal Satisfaction with Life Scale M 2.65 in sample on OP vs. 3.04 retrospective data; interpreted as strong decrease [43]
b Anxiousness, depressivity Three items each of the State-Trait-Anxiety-Depression-Inventory (STADI) M Depressivity 1.91 in sample on OP vs. 1.71 retrospective data; interpreted as moderate increase [43]

Anxiousness 2.02 in sample on OP vs. 1.79 retrospective data; interpreted as moderate increase [43]
Data basis: Online survey of the universities Göttingen and Regensburg

Survey study (online; self-selecting) in general population aged 18–88 years; (n=1,744, 72.2% female); comparison over time with reference sample from 2010, sample adjustment by random deletion of female participants (n=1,001, 52.2% female)

[45] Schelhorn I, Ecker A, Bereznai J et al. (2020): OP: 08.04.–01.06.2020		 c Depressive symptoms ICD-10-Symptom-Rating (ISR)

(> Cut-Offs for moderate or severe symptoms)		 13% moderate and 5% severe symptoms in sample vs. 4.8% and 1.1% in reference sample; interpreted as an indication of possible increase[45]

Particularly in women and in young people, the symptoms are more severe [45]
Data basis: Online survey of the Universities Witten/Herdecke, …

Survey study (online, participant recruitment via snowball system); comparison over time by dividing the sample into three cohorts over the survey period

[44] Büssing A, Rodrigues Recchia D, Dienberg T et al. (2021): OP: June 2020 (n=1,333), July–September 2020 (n=823), October–January 2021 (n=625)		 a Wellbeing WHO-5-Well-being Index (Total) Decrease in the OP October–January 2021 compared to OP June 2020 and OP July–October 2020 [44]
a Satisfaction of life Brief Multidimensional Life Satisfaction Scale Decrease in the OP October–January 2021 compared to OP June 2020 and OP July–October 2020 [44]