Table 1 Basic characteristics of included studies

Wagner et al. /2006/ Germany

Bereaved individuals with depression, intrusion, avoidance, and maladaptive behavior

26

25

Writing assignments based on CBT via email: (1) exposure to bereavement cues; (2) cognitive reappraisal; (3) integration and restoration.

Waiting for treatment

10 times, 45 min / 5 weeks

3-month

Anxiety, Depression

BSI

Dominick et al. /2009/ USA

Individuals who have experienced bereavement within the past 1–6 months

33

34

Making sense of grief intervention: (1) my grieving style; (2) how am I doing? (3) providing resources

Usual care

2 weeks

N/A

Anxiety

STAI

van der Houwen et al. /2010/ Netherland

Bereaved subjects significantly distressed by the loss

201

254

Writing assignments based on CBT via email: (1) exposure; (2) cognitive reappraisal; (3) integration and restoration.

Waiting for treatment

5 times / 5 weeks

3-month

Grief, Depression

9 items based on the DSM-V, CES-D

Kersting et al. /2011/ Germany

Participants who had lost a child during pregnancy

33

26

Writing assignments based on CBT via email: (1) self- confrontation; (2) cognitive restructuring; (3) social sharing

Waiting for treatment

10 times, 45 min / 5 weeks

3-month

PTSD, Grief,

IES, ICG, BSI

Depression, Anxiety

Kersting et al. /2013/ Germany

Parents after the loss of a child during pregnancy

99

100

Writing assignments based on CBT via email: (1) self- confrontation; (2) cognitive restructuring; (3) social sharing

Waiting for treatment

10 times, 45 min / 5 weeks

3-month

PTSD, Grief,

IES-R, ICG, BSI

Depression, Anxiety

Litz et al. /2014/ USA

Bereaved individuals at risk for prolonged grief disorder

32

42

HEAL: (1) education about loss and grief; (2) instruction on stress management and skills; (3) behavioral activation (self-care + social reengagement); (4) accommodation of loss + goal achievement; (5) relapse prevention

Waiting for treatment

18 times, 20 min / 6 weeks

3-month

PTSD, Grief,

PCL-C,

Depression, Anxiety

PG-13,

BDI, BAI

Eisma et al. /2015/ Netherlands

Bereaved individuals with elevated levels of complicated grief and elevated grief

Exposure:15

10

E-mailed homework assignments; Exposure: writing assignments, imaginal and/or in vivo exposure exercises;

Waiting for treatment

6 times / 6–8 weeks

N/A

PTSD, Grief,

PSS,

rumination

Activation:11

Activation: 7- day activity diary, engagement in value-based activities

Depression

ICG-R,

HADS

Brodbeck et al. /2019/ Switzerland

Elders with prolonged grief, psychological

51

47

Internet-based self-help “LIVIA”: (1) information about interpersonal loss and an assessment of the current situation; (2) exposure and

Waiting for treatment

10 times / 5 weeks

3-month

Grief, Depression

TRIG-D, BDI-II

distress or adaptation problems

loss-oriented interventions; (3) resources and restoration-oriented

interventions

Treml et al. /2021/ Germany

Participants with prolonged grief disorder who had lost a close person to suicide

27

27

Internet-based cognitive behavioral grief therapy: (1) self-confrontation; (2) cognitive restructuring;

Waiting for treatment

10 times / 5 weeks

N/A

Grief,

ICG, GEQ

(3) social sharing

Depression

Godzik et al. /2021/ USA

Bereaved adults aged 55 and over

12

14

Online CBT-I: (1) get ready; (2) sleep window; (3) behaviors; (4) thoughts; (5) education; (6) looking ahead

Attention control: (1) insomnia; (2) grief; (3) positivity; (4) healthy eating; (5) exercise; (6) resilience

3 h a week / 6weeks

N/A

Anxiety

DASS Short Form

Depression

Wagner and Hofmann et al. /2022/ Germany

Bereaved siblings aged 16–65 years

47

39

Writing assignments based on CBT via email: (1) self- confrontation; (2) cognitive restructuring; (3) social sharing

Waiting for treatment

12 times, 45 min / 6 weeks

N/A

Grief,

ICG,

Depression, PTSD

BDI-II.

IES-R

Wagner and Grafiadeli et al. /2022/ Germany

Participants who have lost someone close to them to suicide, aged 18-75

52

48

Online group intervention based on CBT which consisted of weekly sessions with topics relevant to suicide survivors (e.g., guilt, stigma)

Waiting for treatment

12 times, 90 min / 12 weeks

3-month

Depression,

ICG-D,

Grief, PTSD

GEQ,

IES-R, PHQ-9

Kaiser et al. /2022/ Germany

Individuals with grief bereaved by cancer

39

42

Online grief therapy via a secure website using the software: (1)self-confrontation; (2) cognitive restructuring; (3) social sharing

Waiting for treatment

10 times, 45 min / 5 weeks

N/A

Grief,

ICG,

Depression, Anxiety, PTSD

PHQ-9, GAD-7, IES-R

Park et al. /2023/ South Korea

Individuals who had experienced family bereavement within a year

18

14

Art therapy via Zoom: (1) looking for images of scribbles; (2) imagining “valuable things”; (3) assuming the role; (4)listening to music; (5) expressing emotions in various elements; (6) watching a movie and expressing feelings; (7) being presented story; (8) sharing images of happy experiences

Waiting for treatment

8 times, 60 min / 8 weeks

N/A

Depression, Grief

BDI-II,

TRIG

Lenferink et al. /2023/ Netherlands

Individuals bereaved

11

17

Individual online CBT: (1) facing the loss and the pain; (2) keeping faith in life and the future; (3) doing helpful things.

Waiting for treatment

8 lessons / 12 weeks

N/A

Grief,

TGI-SR+,

through traffic accidents at least 1 year previously

PTSD, Depression

PCL-5, HADS-D

Reitsma et al. /2023/ Netherlands

Adults who lost a spouse, family member, or friend due to various causes, at least three months earlier during the pandemic.

19

32

Self-guided online CBT treatment: (1) exposure (2) cognitive restructuring; (3) expanded by an online protocol addressing behavioral activation

Waiting for treatment

8 lessons,2 h / 12 weeks

N/A

Grief, PTSD, Depression

TGI-CA, PCL-5, PHQ-9