. 2021 May 17;33(6):1729–1743. doi: 10.1007/s40520-021-01873-4

Table 1.

Characteristics and results of studies included in the review (n = 18)

First author; publication date; country	Study design; study period	Study participants	Psychometric tools; outcome*	Results
Solomou I; July 2020; Cyprus [33]	Cross-sectional online survey; April 3 to April 9, 2020	63 participants aged > 60 (3.8% among a total of 1,642 respondents); (M_AGE not reported)	PHQ-9; depression^a GAD-7; anxiety^b	Compared with younger participants, older adults showed significantly: - lower mean PHQ-9 score (M = 3.90, SD = 3.57) - lower mean GAD-7 score (M = 4.83, SD = 4.22)
Nwachukwu I; September 2020; Canada [34]	Cross-sectional online survey; March 23, 2020	762 participants aged > 60 (9.2% among a total of 8,267 respondents); (M_AGE not reported)	PHQ-9; depression^a GAD-7; anxiety^b PSS; perceived stress^c	Compared with younger participants, older adults showed significantly: - lower mean PHQ-9 score (M = 6.65, SD = 5.60) - lower mean GAD-7 score (M = 6.35, SD = 5.17) - lower mean PSS score (M = 16.65, SD = 6.77)
Pieh C; September 2020; Austria [35]	Cross-sectional online survey; two-week study until April 30, 2020	133 participants aged ≥ 65 (13.2% among a total of 1005 respondents); (M_AGE not reported)	PHQ-9: depression^a GAD-7: anxiety^b PSS-10: stress^c ISI: insomnia^d WHO-QOL BREF: quality-of-life^e WHO-5: wellbeing^f	Compared with younger participants, older adults showed significantly: - lower mean PHQ-9 score (M = 3.74, SD = 3.95) - lower mean GAD-7 score (M = 3.85, SD = 3.97) - lower mean PSS-10 score (M = 12.73, SD = 6.80) - lower mean ISI score (M = 6.11, SD = 4.51) - higher mean WHO-QOL BREF score (M = 75.08, SD = 15.82) - higher mean WHO-5 score (M = 17.18, SD = 4.97)
Minahan J; December 2020; United States [36]	Cross-sectional online survey; April 1 to May 17, 2020	398 participants aged 65-92 (30% among a total of 1,318 respondents); (M_AGE = 71.32, SD = 5.10)	PHQ-9; depression^a GAD-7; anxiety^b IES-R; post-traumatic stress disorder symptoms^g UCLA-3; loneliness^h	Compared with younger participants, older adults showed significantly: - lower mean PHQ-9 score (M = 13.18, SD = 4.38) - lower mean GAD-7 score (M = 9.99, SD = 3.94) - lower mean IES-R score (M = 0.81, SD = 0.55) - lower mean UCLA-3 score (M = 4.58, SD = 1.62)
García-Portilla P; September 2020; Spain [37]	Cross-sectional online survey; March 19 to March 26, 2020	1690 participants aged ≥ 60 (M_AGE = 65.9, SD = 5.1) versus 13,363 participants aged < 60	DASS-21; depression, anxiety, stressⁱ IES; stress reactions (intrusive thoughts-avoidance behaviours) after traumatic events^j	Compared with younger participants, older adults showed significantly: - lower mean DASS-21 scores (females: subscale Depression M = 3.2, SD = 0.9; subscale Anxiety M = 0.6, SD= 1.0; subscale Stress M = 1.1, SD = 1.6/males: subscale Depression M = 3.0, SD = 0.9; subscale Anxiety M = 0.3, SD = 0.7; subscale Stress M = 0.7, SD = 1.4) - lower mean IES scores (females: subscale Intrusion M = 1.7, SD = 1.7; subscale Avoidance M = 2.8, SD = 1.8/males: subscale Intrusion M = 1.2, SD = 1.5; subscale Avoidance M = 2.2, SD = 1.8)
Justo-Alonso A; November 2020; Spain [38]	Cross-sectional online survey; March 23 to March 28, 2020	204 participants aged 60–79 (5.8% among a total of 3524 respondents); (M_AGE not reported)	DASS-21; depression, anxiety, stressⁱ IES-R; post-traumatic stress disorder symptoms^g	Compared with younger participants, older adults showed significantly: - lower mean Global DASS scores (M = 10.46, SD = 9.66) - lower mean DASS subscale Depression score (M = 3.30, SD = 3.33) - lower mean DASS subscale Anxiety score (M = 2.52, SD = 3.02) - lower mean DASS subscale Stress score (M = 4.64, SD = 4.34) - lower mean Global IES-R score (M = 20.15, SD = 11.03) - lower mean IES-R subscale Hyperarousal score (M = 3.94, SD = 3.33) - lower mean IES-R subscale Avoidance score (M = 8.39, SD = 4.36) - lower mean IES-R subscale Intrusions score (M = 7.82, SD = 4.95)
García-Fernández L; October 2020; Spain [39]	Cross-sectional online survey; March 29 to April 5, 2020	150 participants aged ≥ 60 (9.1% among a total of 1,639 respondents); (M_AGE not reported)	BDI; depression^k HARS; anxiety^l ASDI; acute stress symptoms^m	Compared with younger participants, older adults showed: - significantly lower mean BDI scores (Mean = 3.02, SD = 3.28) - lower mean HARS scores (Mean = 15.39, SD = 10.94) - significantly lower mean ASDI scores (Mean = 3.68, SD = 3.20)
Shrira A; November 2020; Israel [40]	Cross-sectional online survey; March 16 to April 14, 2020	277 participants aged ≥ 60; (M_AGE = 69.58, SD = 6.72)	PHQ-9; depression^a GAD-7; anxiety^b PDI; peritraumatic distress symptomsⁿ UCLA-3; loneliness^h	Low mean PHQ-9 score (M = 3.33, SD = 4.10) Low mean GAD-7 score (M = 2.95, SD = 3.82) Low mean PDI score (M = 9.45, SD = 6.51) Low mean UCLA-3 score (M = 2.28, SD = 0.90)
Wilson JM; December 2020; United States [41]	Cross-sectional online survey; March 30 to April 5, 2020	263 participants aged ≥ 60 (31% among a total of 848 respondents); (M_AGE = 68.35, SD = 5.16)	PHQ-8; depression^o GAD-7; anxiety^b	Older adults on average reported: - minimal/none depressive symptoms (M_PHQ-8 = 2.89, SD = 4.07) - minimal/none anxiety symptoms (M_GAD-7 = 3.42, SD = 4.79)
Röhr S; November 2020; Germany [42]	Cross-sectional telephone interview; April 6 to April 25, 2020	1005 participants aged ≥ 65; (M_AGE = 75.5, SD = 7.1)	BSI-18; global psychological distress (depression, anxiety, somatisation)^p UCLA-3; loneliness^h	Based on estimates reported before the pandemic, BSI-18 and UCLA-3 mean scores did not indicate worsening during the pandemic: - mean BSI-18 scores for depression (M = 1.38, SD = 1.97) - mean BSI-18 score for anxiety (M = 1.60, SD = 1.98) - mean BSI-18 score for somatisation (M = 2.16, SD = 2.77) - global psychological distress (M = 5.13, SD = 5.49) - mean UCLA-3 scores (M = 4.13, SD = 1.36)
Krendl AC; August 2020; Indiana, United States [43]	Study comparing data prior with data during the pandemic; pre-pandemic assessment (interview type not specified) June to October 2019; peri-pandemic assessment (phone interview) April 21 to May 21, 2020	Pre-pandemic assessment: 120 participants (M_AGE= 74.68, SD = 7.13); peri-pandemic assessment: 94 of the original participants (M_AGE= 75.20, SD = 6.86)	PHQ-8: depression^o GAD-7: anxiety^b PSS-10: stress^c UCLA-3: loneliness^h	Mean scale scores at the pre-pandemic assessment significantly increased at the peri-pandemic assessment: - PHQ-8 pre-pandemic assessment (M = 2.40, SD = 2.71) versus peri-pandemic assessment (M = 3.24, SD = 3.24) - GAD-7 pre-pandemic assessment (M = 1.76, SD = 2.81) versus peri-pandemic assessment (M = 2.98, SD = 3.74) - PSS-10 pre-pandemic assessment (M = 19.36, SD = 5.95) versus peri-pandemic assessment (M = 26.49, SD = 2.43) - UCLA-3 pre-pandemic assessment (M = 5.14, SD = 2.49) versus peri-pandemic assessment (M = 6.05, SD = 2.83)
van Tilburg TG; August 2020; Netherlands [44]	Longitudinal Internet Studies for the Social Sciences panel; pre-pandemic assessment (phone/in-person interview) October-November 2019; peri-pandemic assessment (online survey) May 4 to May 26, 2020	1679 participants aged 65-102; (M_AGE = 73, SD not reported)	MHI-5; mental health state^q DJGLS; loneliness^r	Mean scale scores at the pre-pandemic assessment significantly increased at the peri-pandemic assessment: - MHI-5 pre-pandemic assessment (M = 4.93, SD = 0.75) versus peri-pandemic assessment (M = 5.02, SD = 0.73) - DJGLS social loneliness pre-pandemic assessment (M = 0.95, SD = 1.15) versus peri-pandemic assessment (M = 1.17, SD = 1.20) - DJGLS emotional loneliness pre-pandemic assessment (M = 0.48, SD = 0.91) versus peri-pandemic assessment (M = 0.97, SD = 0.97)
Heidinger T; September 2020; Lower Austria [45]	Study comparing data prior with data during the pandemic; pre-pandemic assessment (telephone survey) April-July, 2019; peri-pandemic assessment (telephone survey) April-May, 2020	888 matched participants (444:444) aged 60-99; (M_AGE = 73, SD = 8.17)	DJGLS; loneliness^r	Mean DJGLS score before the pandemic (M = 1.61, SD = 0.55) significantly increased during the pandemic (M = 1.73, SD = 0.60)
Fujita K; January 2021; Japan [46]	Study comparing data prior with data during the pandemic (questionnaire survey not specified); pre-pandemic assessment December 2019; post-pandemic assessment July 2020	519 participants; (M_AGE= 74.8, SD = 5.3)	GDS-15; depression^s Apathy Scale^t	Mean scale scores at the pre-pandemic assessment significantly increased at the post-pandemic assessment: - GDS-15 pre-pandemic assessment (M = 2.94, SD = 3.27) versus post-pandemic assessment (M = 3.62, SD = 3.41) - Apathy Scale pre-pandemic assessment (M = 13.65, SD = 6.70) versus post-pandemic assessment (M = 15.20, SD = 6.98)
Wong SYS; October 2020; Hong Kong [47]	Study comparing data prior with data during the pandemic; pre-pandemic assessment (in-person) April 3, 2018, to March 6, 2019; peri-pandemic assessment (telephone interviews) March 24 to April 15, 2020	583 participants aged ≥60; (M_AGE = 70.9, SD = 6.1)	PHQ-9; depression^a GAD-7; anxiety^b ISI; insomnia^d DJGLS; loneliness^r	Mean scale scores at the pre-pandemic assessment significantly increased at the peri-pandemic assessment: - GAD-7 pre-pandemic assessment (M = 2.5, 98% CI [2.2, 2.8]) versus peri-pandemic assessment (M = 3.0, 98% CI [2.7, 3.3]) - ISI pre-pandemic assessment (M = 6.9, 98% CI [6.5, 7.3]) versus peri-pandemic assessment (M = 7.5, 98% CI [7.1, 7.9]) - DJGLS pre-pandemic assessment (M = 1.6, 98% CI [1.4, 1.7]) versus peri-pandemic assessment (M = 2.9, 98% CI [2.7, 3.1]) - DJGLS social loneliness pre-pandemic assessment (M = 0.8, 98% CI [0.7, 0.9]) versus peri-pandemic assessment (M = 1.7, 98% CI [1.6, 1.8]) - DJGLS emotional loneliness pre-pandemic assessment (M = 0.7, 98% CI [0.7, 0.8]) versus peri-pandemic assessment (M = 1.2, 98% CI [1.1, 1.3]) Depressive symptoms did not change significantly: PHQ-9 pre-pandemic assessment (M = 4.4, 98% CI [4.0, 4.7]) versus peri-pandemic assessment (M = 4.5, 98% CI [4.2, 4.9])
Giebel C; September 2020; United Kingdom [48]	Baseline data from an ongoing, longitudinal online and telephone survey; April 17 to May 15, 2020	223 participants aged 65–90; (M_AGE = 72, SD = 6)	PHQ‐9; depression^a GAD‐7; anxiety^b SWEMWBS; wellbeing^u	PHQ-9 Median = 2, range = 0–19 GAD-7 Median = 1, range = 0–18 SWEMWBS Median = 28, range = 11–35
Robb CE; September 2020; London, United Kingdom [49]	Baseline data from an ongoing longitudinal online survey; April 30 to July 8, 2020	7127 participants aged 50-100; (M_AGE = 70.7, SD = 7.4)	HADS; anxiety and depression^v	HADS Depression scores: - 5114 participants (90.8%) within the normal range - 375 participants (6.7%) borderline cases - 142 participants (2.5%) cases HADS Anxiety scores: - 4774 participants (84.8%) within the normal range - 550 participants (9.8%) borderline cases - 307 participants (5.5%) cases
Kivi M; June 2020; Sweden [50]	Longitudinal study; baseline data from March-June 2015; 2020 data from March 26 to April 2	1071 participants aged 65-71; (M_AGE = 68.1, SD = 2.0)	UCLA Loneliness Scale-R; loneliness^w SWLS; satisfaction with life^x	Participant’s mean scale scores during the pandemic did not significantly deviate from mean scores over the past 5 years: - UCLA score in 2015 (M = 1.46, SD = 0.59); in 2020 (M = 1.44, SD = 0.59) - SWLS score in 2015 (M = 4.97, SD = 1.27); in 2020 (M = 5.16, SD = 1.26)

First author; publication date; country

Study design; study period

Study participants

Psychometric tools; outcome*

Results

Solomou I;

July 2020; Cyprus [33]

Cross-sectional online survey;

April 3 to April 9, 2020

63 participants aged > 60 (3.8% among a total of 1,642 respondents);

(M_AGE not reported)

PHQ-9; depression^a

GAD-7; anxiety^b

Compared with younger participants, older adults showed significantly:

- lower mean PHQ-9 score (M = 3.90, SD = 3.57)

- lower mean GAD-7 score (M = 4.83, SD = 4.22)

Nwachukwu I;

September 2020; Canada [34]

Cross-sectional online survey;

March 23, 2020

762 participants aged > 60 (9.2% among a total of 8,267 respondents);

(M_AGE not reported)

PHQ-9; depression^a

GAD-7; anxiety^b

PSS; perceived stress^c

Compared with younger participants, older adults showed significantly:

- lower mean PHQ-9 score (M = 6.65, SD = 5.60)

- lower mean GAD-7 score (M = 6.35, SD = 5.17)

- lower mean PSS score (M = 16.65, SD = 6.77)

Pieh C;

September 2020; Austria [35]

Cross-sectional online survey;

two-week study until April 30, 2020

133 participants aged ≥ 65 (13.2% among a total of 1005 respondents);

(M_AGE not reported)

PHQ-9: depression^a

GAD-7: anxiety^b

PSS-10: stress^c

ISI: insomnia^d

WHO-QOL BREF: quality-of-life^e

WHO-5: wellbeing^f

Compared with younger participants, older adults showed significantly:

- lower mean PHQ-9 score (M = 3.74, SD = 3.95)

- lower mean GAD-7 score (M = 3.85, SD = 3.97)

- lower mean PSS-10 score (M = 12.73, SD = 6.80)

- lower mean ISI score (M = 6.11, SD = 4.51)

- higher mean WHO-QOL BREF score (M = 75.08, SD = 15.82)

- higher mean WHO-5 score (M = 17.18, SD = 4.97)

Minahan J;

December 2020; United States [36]

Cross-sectional online survey;

April 1 to May 17, 2020

398 participants aged 65-92 (30% among a total of 1,318 respondents);

(M_AGE = 71.32, SD = 5.10)

PHQ-9; depression^a

GAD-7; anxiety^b

IES-R; post-traumatic stress disorder symptoms^g

UCLA-3; loneliness^h

Compared with younger participants, older adults showed significantly:

- lower mean PHQ-9 score (M = 13.18, SD = 4.38)

- lower mean GAD-7 score (M = 9.99, SD = 3.94)

- lower mean IES-R score (M = 0.81, SD = 0.55)

- lower mean UCLA-3 score (M = 4.58, SD = 1.62)

García-Portilla P; September 2020; Spain [37]

Cross-sectional online survey;

March 19 to March 26, 2020

1690 participants aged ≥ 60 (M_AGE = 65.9, SD = 5.1) versus 13,363 participants aged < 60

DASS-21; depression, anxiety, stressⁱ

IES; stress reactions (intrusive thoughts-avoidance behaviours) after traumatic events^j

Compared with younger participants, older adults showed significantly:

- lower mean DASS-21 scores (females: subscale Depression M = 3.2, SD = 0.9; subscale Anxiety M = 0.6, SD= 1.0; subscale Stress M = 1.1, SD = 1.6/males: subscale Depression M = 3.0, SD = 0.9; subscale Anxiety M = 0.3, SD = 0.7; subscale Stress M = 0.7, SD = 1.4)

- lower mean IES scores (females: subscale Intrusion M = 1.7, SD = 1.7; subscale Avoidance M = 2.8, SD = 1.8/males: subscale Intrusion M = 1.2, SD = 1.5; subscale Avoidance M = 2.2, SD = 1.8)

Justo-Alonso A;

November 2020; Spain [38]

Cross-sectional online survey;

March 23 to March 28, 2020

204 participants aged 60–79 (5.8% among a total of 3524 respondents);

(M_AGE not reported)

DASS-21; depression, anxiety, stressⁱ

IES-R; post-traumatic stress disorder symptoms^g

Compared with younger participants, older adults showed significantly:

- lower mean Global DASS scores (M = 10.46, SD = 9.66)

- lower mean DASS subscale Depression score (M = 3.30, SD = 3.33)

- lower mean DASS subscale Anxiety score (M = 2.52, SD = 3.02)

- lower mean DASS subscale Stress score (M = 4.64, SD = 4.34)

- lower mean Global IES-R score (M = 20.15, SD = 11.03)

- lower mean IES-R subscale Hyperarousal score (M = 3.94, SD = 3.33)

- lower mean IES-R subscale Avoidance score (M = 8.39, SD = 4.36)

- lower mean IES-R subscale Intrusions score (M = 7.82, SD = 4.95)

García-Fernández L; October 2020; Spain [39]

Cross-sectional online survey;

March 29 to April 5, 2020

150 participants aged ≥ 60 (9.1% among a total of 1,639 respondents);

(M_AGE not reported)

BDI; depression^k

HARS; anxiety^l

ASDI; acute stress symptoms^m

Compared with younger participants, older adults showed:

- significantly lower mean BDI scores (Mean = 3.02, SD = 3.28)

- lower mean HARS scores (Mean = 15.39, SD = 10.94)

- significantly lower mean ASDI scores (Mean = 3.68, SD = 3.20)

Shrira A;

November 2020; Israel [40]

Cross-sectional online survey;

March 16 to April 14, 2020

277 participants aged ≥ 60;

(M_AGE = 69.58, SD = 6.72)

PHQ-9; depression^a

GAD-7; anxiety^b

PDI; peritraumatic distress symptomsⁿ

UCLA-3; loneliness^h

Low mean PHQ-9 score (M = 3.33, SD = 4.10)

Low mean GAD-7 score (M = 2.95, SD = 3.82)

Low mean PDI score (M = 9.45, SD = 6.51)

Low mean UCLA-3 score (M = 2.28, SD = 0.90)

Wilson JM;

December 2020; United States [41]

Cross-sectional online survey;

March 30 to April 5, 2020

263 participants aged ≥ 60 (31% among a total of 848 respondents);

(M_AGE = 68.35, SD = 5.16)

PHQ-8; depression^o

GAD-7; anxiety^b

Older adults on average reported:

- minimal/none depressive symptoms (M_PHQ-8 = 2.89, SD = 4.07)

- minimal/none anxiety symptoms (M_GAD-7 = 3.42, SD = 4.79)

Röhr S;

November 2020; Germany [42]

Cross-sectional telephone interview;

April 6 to April 25, 2020

1005 participants aged ≥ 65;

(M_AGE = 75.5, SD = 7.1)

BSI-18; global psychological distress (depression, anxiety, somatisation)^p

UCLA-3; loneliness^h

Based on estimates reported before the pandemic, BSI-18 and UCLA-3 mean scores did not indicate worsening during the pandemic:

- mean BSI-18 scores for depression (M = 1.38, SD = 1.97)

- mean BSI-18 score for anxiety (M = 1.60, SD = 1.98)

- mean BSI-18 score for somatisation (M = 2.16, SD = 2.77)

- global psychological distress (M = 5.13, SD = 5.49)

- mean UCLA-3 scores (M = 4.13, SD = 1.36)

Krendl AC;

August 2020; Indiana, United States [43]

Study comparing data prior with data during the pandemic;

pre-pandemic assessment (interview type not specified) June to October 2019;

peri-pandemic assessment (phone interview) April 21 to May 21, 2020

Pre-pandemic assessment: 120 participants (M_AGE= 74.68, SD = 7.13);

peri-pandemic assessment: 94 of the original participants (M_AGE= 75.20, SD = 6.86)

PHQ-8: depression^o

GAD-7: anxiety^b

PSS-10: stress^c

UCLA-3: loneliness^h

Mean scale scores at the pre-pandemic assessment significantly increased at the peri-pandemic assessment:

- PHQ-8 pre-pandemic assessment (M = 2.40, SD = 2.71) versus peri-pandemic assessment (M = 3.24, SD = 3.24)

- GAD-7 pre-pandemic assessment (M = 1.76, SD = 2.81) versus peri-pandemic assessment (M = 2.98, SD = 3.74)

- PSS-10 pre-pandemic assessment (M = 19.36, SD = 5.95) versus peri-pandemic assessment (M = 26.49, SD = 2.43)

- UCLA-3 pre-pandemic assessment (M = 5.14, SD = 2.49) versus peri-pandemic assessment (M = 6.05, SD = 2.83)

van Tilburg TG;

August 2020; Netherlands [44]

Longitudinal Internet Studies for the Social Sciences panel;

pre-pandemic assessment (phone/in-person interview) October-November 2019;

peri-pandemic assessment (online survey) May 4 to May 26, 2020

1679 participants aged 65-102;

(M_AGE = 73, SD not reported)

MHI-5; mental health state^q

DJGLS; loneliness^r

Mean scale scores at the pre-pandemic assessment significantly increased at the peri-pandemic assessment:

- MHI-5 pre-pandemic assessment (M = 4.93, SD = 0.75) versus peri-pandemic assessment (M = 5.02, SD = 0.73)

- DJGLS social loneliness pre-pandemic assessment (M = 0.95, SD = 1.15) versus peri-pandemic assessment (M = 1.17, SD = 1.20)

- DJGLS emotional loneliness pre-pandemic assessment (M = 0.48, SD = 0.91) versus peri-pandemic assessment (M = 0.97, SD = 0.97)

Heidinger T;

September 2020; Lower Austria [45]

Study comparing data prior with data during the pandemic;

pre-pandemic assessment (telephone survey) April-July, 2019;

peri-pandemic assessment (telephone survey) April-May, 2020

888 matched participants (444:444) aged 60-99;

(M_AGE = 73, SD = 8.17)

DJGLS; loneliness^r

Mean DJGLS score before the pandemic (M = 1.61, SD = 0.55) significantly increased during the pandemic (M = 1.73, SD = 0.60)

Fujita K;

January 2021; Japan [46]

Study comparing data prior with data during the pandemic (questionnaire survey not specified);

pre-pandemic assessment December 2019;

post-pandemic assessment July 2020

519 participants;

(M_AGE= 74.8, SD = 5.3)

GDS-15; depression^s

Apathy Scale^t

Mean scale scores at the pre-pandemic assessment significantly increased at the post-pandemic assessment:

- GDS-15 pre-pandemic assessment (M = 2.94, SD = 3.27) versus post-pandemic assessment (M = 3.62, SD = 3.41)

- Apathy Scale pre-pandemic assessment (M = 13.65, SD = 6.70) versus post-pandemic assessment (M = 15.20, SD = 6.98)

Wong SYS;

October 2020; Hong Kong [47]

Study comparing data prior with data during the pandemic;

pre-pandemic assessment (in-person) April 3, 2018, to March 6, 2019;

peri-pandemic assessment (telephone interviews) March 24 to April 15, 2020

583 participants aged ≥60;

(M_AGE = 70.9, SD = 6.1)

PHQ-9; depression^a

GAD-7; anxiety^b

ISI; insomnia^d

DJGLS; loneliness^r

Mean scale scores at the pre-pandemic assessment significantly increased at the peri-pandemic assessment:

- GAD-7 pre-pandemic assessment (M = 2.5, 98% CI [2.2, 2.8]) versus peri-pandemic assessment (M = 3.0, 98% CI [2.7, 3.3])

- ISI pre-pandemic assessment (M = 6.9, 98% CI [6.5, 7.3]) versus peri-pandemic assessment (M = 7.5, 98% CI [7.1, 7.9])

- DJGLS pre-pandemic assessment (M = 1.6, 98% CI [1.4, 1.7]) versus peri-pandemic assessment (M = 2.9, 98% CI [2.7, 3.1])

- DJGLS social loneliness pre-pandemic assessment (M = 0.8, 98% CI [0.7, 0.9]) versus peri-pandemic assessment (M = 1.7, 98% CI [1.6, 1.8])

- DJGLS emotional loneliness pre-pandemic assessment (M = 0.7, 98% CI [0.7, 0.8]) versus peri-pandemic assessment (M = 1.2, 98% CI [1.1, 1.3])

Depressive symptoms did not change significantly: PHQ-9 pre-pandemic assessment (M = 4.4, 98% CI [4.0, 4.7]) versus peri-pandemic assessment (M = 4.5, 98% CI [4.2, 4.9])

Giebel C;

September 2020; United Kingdom [48]

Baseline data from an ongoing, longitudinal online and telephone survey;

April 17 to May 15, 2020

223 participants aged 65–90;

(M_AGE = 72, SD = 6)

PHQ‐9; depression^a

GAD‐7; anxiety^b

SWEMWBS; wellbeing^u

PHQ-9 Median = 2, range = 0–19

GAD-7 Median = 1, range = 0–18

SWEMWBS Median = 28, range = 11–35

Robb CE;

September 2020; London, United Kingdom [49]

Baseline data from an ongoing longitudinal online survey;

April 30 to July 8, 2020

7127 participants aged 50-100;

(M_AGE = 70.7, SD = 7.4)

HADS; anxiety and depression^v

HADS Depression scores:

- 5114 participants (90.8%) within the normal range

- 375 participants (6.7%) borderline cases

- 142 participants (2.5%) cases

HADS Anxiety scores:

- 4774 participants (84.8%) within the normal range

- 550 participants (9.8%) borderline cases

- 307 participants (5.5%) cases

Kivi M;

June 2020; Sweden [50]

Longitudinal study; baseline data from March-June 2015;

2020 data from March 26 to April 2

1071 participants aged 65-71;

(M_AGE = 68.1, SD = 2.0)

UCLA Loneliness Scale-R; loneliness^w

SWLS; satisfaction with life^x

Participant’s mean scale scores during the pandemic did not significantly deviate from mean scores over the past 5 years:

- UCLA score in 2015 (M = 1.46, SD = 0.59); in 2020 (M = 1.44, SD = 0.59)

- SWLS score in 2015 (M = 4.97, SD = 1.27); in 2020 (M = 5.16, SD = 1.26)

^*Single-item questions to assess loneliness or fear of COVID-19, non-validated questionnaires and tools assessing parameters irrelevant to the review’s scope, e.g., resilience, frailty status, subjective age, personality traits, were not included

^aPHQ-9: Patient Health Questionnaire 9-item depression scale (score range 0–27; cutoff points: 0–4 = minimal/none, 5–9 = mild, 10–14 = moderate, 15–19 = moderately severe, 20–27 = severe)

^bGAD-7: Generalised Anxiety Disorder 7-item scale (score range 0–21; cutoff points: 0–5 = mild; 6–10 = moderate; 11–15 = moderately severe; 15–21 = severe)

^cPSS-10: Perceived Stress Scale (score range 0–40; cutoff points: 0–13 = low, 14–26 = moderate, 27–40 = high)

^dISI: Insomnia Severity Index [score range 0–28; cutoff points: < 7 no clinically significant insomnia, 8–14 subthreshold insomnia, 15–21 clinical insomnia (moderate), 22–28 clinical insomnia (severe); a cutoff point of 10 was optimal for detecting insomnia cases in the community; the authors [35] applied a cutoff point of 15)]

^eWHO-QOL BREF: WHO Quality of life-BREF (score range 0–100; higher scores indicate better quality of life)

^fWHO-5: World Health Organization-five well-being index (raw score range 0–25; higher scores indicate better wellbeing)

^gIES-R: Impact of Event Scale-Revised (score range 0–88; cutoff point ≥ 33 for probable PTSD)

^hUCLA-3: University of California Los Angeles loneliness scale [score range 3–9; cutoff points: 3–5 = not lonely, 6–9 = lonely; the authors [40] rated items on a 5-point scale (1 = not at all to 5 = almost always) instead of the standard 3-point scale (1 = hardly ever to 3 = often)]

ⁱDASS-21: Depression, Anxiety, and Stress Scale (score range 0–21 for the 7-item subscales for depression, anxiety and stress; Depression subscale cutoff points: 0–4 = normal, 5–6 = mild, 7–10 = moderate, 11–13 = severe, > 14 extremely severe; Anxiety subscale cutoff points: 0–3 = normal, 4–5 = mild, 6–7 = moderate, 8–9 = severe, > 10 extremely severe; Stress subscale cutoff points: 0–7 = normal, 8–9 = mild, 10–12 = moderate, 13–16 = severe, > 17 extremely severe)

^jIES: Impact of Event Scale [score range 0–75; cutoff points: ≤ 8.5: low, 8.6–19: medium, (> 19) ≥ 26: high]

^kBDI: Beck Depression Inventory (score range 0–63; cutoff points: 0–9 = minimal, 10–18 = mild, 19–29 = moderate, 30–63 = severe);

^lHARS: Hamilton Anxiety Rating Scale (score range 0–56; cutoff points: < 17: mild, 18–24 = mild to moderate, 25–30 = moderate to severe)

^mASDI: Acute Stress Disorder Interview (score range 0–19; each of Criteria A-E need to be satisfied; Criterion B requires endorsement of at least nine symptoms)

ⁿPDI: Peritraumatic Distress Inventory (score range 0–52; higher scores indicate increased distress)

^oPHQ-8: abbreviated 8-item PHQ-9 version (item about suicidal ideation is excluded)

^pBSI-18: Brief Symptom Inventory [score range 0–24 for the 6-item subscales for depression, anxiety, somatization; score range 0–72 for the Global Severity Index; the authors [42] used the raw 0–4 item rating score to report mean (SD) values]

^qMHI-5: Mental Health Inventory [raw scores 5–30 are transformed to a 0–100-point scale; higher scores represent optimal mental health; the authors [44] used the raw 1–6 item rating score to report mean (SD) values]

^rDJGLS: De Jong Gierveld loneliness scale (score range 0–3 for both emotional and social loneliness; score range 0–6 for total loneliness)

^sGDS-15: Geriatric Depression Scale (score range 0–15; cutoff points: 0–4 = normal, 5–8 = mild, 9–11 = moderate, 12–15 = severe)

^tApathy Scale (score range 0–42; cutoff point: ≥ 14 = apathy)

^uSWEMWBS: Short Warwick‐Edinburgh Mental Wellbeing Scale (score range 0–35; higher scores indicate higher levels of wellbeing)

^vHADS: Hospital Anxiety and Depression Scale (score range 0–21 for both anxiety and depression subscales; cutoff points 0–7 = normal, 8–10 = borderline case, 11–21 = case)

^wThe authors [50] applied items 2, 5, 11, and 14 from the UCLA-R Loneliness Scale; the raw 1–4 item rating score was used to report mean (SD) values

^xSWLS: Satisfaction With Life Scale [score range 5–35; cutoff points: 5–9 = extremely dissatisfied, 20 = neutral point, 31–35 = extremely satisfied; the authors [50] used the raw 1–7 item rating score to report mean (SD) values]