ABCDEFGHIJKLMNOPQR
1
InterventionEffect SizeEvidenceTime efficiency
2
Hedge's gTop studyNumber of meta-analyses reviewedNumber of studies included in the meta-analysesNumber of participantsPercentage of meta-analyses with a significant (positive) resultConsistency of findingsRough estimation of the ranges of duration for the intervention in total"Time efficiency score" (middle range of the time estimation divided by effect size): the lower the betterOur rough judgement
3
Most promising interventions with the strongest evidence base
4
Mindfulness/Meditation interventionsPracticing meditation regularly, using techniques such as body scan and diaphragmatic breathingSmall0.39Galante et al. (2021)9124> 7,81989%Low.
Range in effect size from 0 to 0.86 (=0.86)
4 to 65 hours88Moderate.
5
Best Possible SelfImagining and writing about your life and the best version of yourself in the future after everything has gone as well as it possibly couldSmall0.35Heekerens and Eid (2021)6149> 12,50283%Moderate.
Range in effect size from 0.21 to 0.51 (=0.30)
1 to 14 hours23High.
6
Compassion interventions (including self-compassion and loving-kindness meditation)Following practices aimed at increasing compassionate attitudes towards others and yourself, like compassion-focused therapy or loving-kindness meditationSmall0.35Kirby et al. (2017)665> 3,94867%Moderate.
Range in effect size from 0.19 to 0.51 (=0.32)
20 min to 20 hours36High.
7
Physical activityDoing some exercise, whatever the type or intensitySmall0.31Buecker et al. (2020)5222> 527,31460%Moderate.
Range in effect size from 0.19 to 0.58 (=0.39)
5 to 130 hours186Low.
8
Multi-component Positive Psychology Interventions (MPPIs) (in general)Following a combined package of a variety of positive psychology exercises like using strengths, practicing gratitude, active constructive response, counting blessings or savoring, often conducted within an integral programSmall0.30Hendriks et al. (2020)3109> 12,412100%High.
Range in effect size from 0.24 to 0.34 (=0.10)
2 to 36 hours63Moderate.
9
Promising interventions with the strongest evidence base but a smaller effect size
10
Using character strengthsIdentifying positive qualities through a self-report survey and using them in your daily life for a period of timeSmall0.29Carr et al. (2021)332> 2,179100%High.
Range in effect size from 0.25 to 0.42 (=0.17)
2 to 52 hours34High.
11
Acts of kindnessPerforming small actions embodying a kind behavior to help other people, or spending money on othersSmall0.26Curry et al. (2018)347> 4,841100%Very high.
Range in effect size from 0.23 to 0.28 (=0.05)
About 3 hours12High.
12
GratitudeEngaging in brief activities designed to cultivate a sense of gratefulness, such as daily writing of things for which you are grateful, or expressing gratitude through a letter to someone who has been helpful to youSmall0.22Dickens (2017)5144> 7,57180%Moderate.
Range in effect size from -0.05 to 0.30 (=0.35)
2 to 24 hours57Moderate.
13
Singular Positive Psychology Interventions (in general)Practicing an individual exercise from positive psychology, such as doing a best possible self exercise, practicing gratitude, doing acts of kindness, using your strengths in a new way or savoring the momentSmall0.20Koydemir et al. (2021)3128> 13,610100%Very high.
Range in effect size from 0.14 to 0.22 (=0.08)
2 to 24 hours65Moderate.
14
Acceptance and Commitement Therapy (ACT)Following an intervention based on ACT principles. ACT interventions seek to increase psychological flexibility (defined as the ability to face challenging experiences in an open, conscious manner and change one’s behaviors to participate in valued activities) through acceptance of difficult and unwelcome thoughts or emotions and a commitment to one’s personal values. For instance they use techniques like mindfulness or exposure exercises to develop cognitive defusion skillsSmall0.20van Agteren et al. (2021)639> 1,75850%Moderate.
Range in effect size from 0 to 0.44 (=0.44)
6 to 36 hours175Low.
15
Cognitive therapy or CBT interventionsFollowing an intervention or program (including in a book or online program format), typically over multiple sessions, using a cognitive and/or behavioral approach. They generally focus on identifying and disputing maladaptive thinking patterns, and developing coping, emotional regulation, problem solving and goal setting skillsVery small0.19van Agteren et al. (2021)218> 4,156100%Very high.
Range in effect size from 0.16 to 0.22 (=0.06)
14 to 26 hours105Low.
16
Most promising interventions with a weaker evidence base
17
LeisureImproving your leisure engagement, i.e. the participation in satisfying leisure activities such as social activities, sports, games, or cultural experiencesLarge1.02Kuykendall et al. (2015)16325100%Only one effect sizeAbout 104 hours102Low.
18
SleepFollowing an intervention aimed at improving sleep quality (i.e. continuity and daytime impact) such as CBTiMedium0.54Scott et al. (2021)2708,717100%High.
Range in effect size from 0.53 to 0.63 (=0.10)
12 minutes to 7 hours7High.
19
Contact with natural environment (or nature connectedness)Spending some time in a natural environnement (whether "wild" or "manicured" nature such as parks), like talking a walk or looking at the landscape, or even viewing nature photographsMedium0.50McMahan and Estes (2015)36110,389100%Moderate.
Range in effect size from 0.35 to 0.65 (=0.30)
15 to 60 minutes for experimental designs-Probably high.
20
YogaPracticing yoga a few times per week, whatever the typeSmall0.46Hendriks et al. (2017)3211,20167%High.
Range in effect size from 0.38 to 0.62 (=0.24)
30 minutes to 60 hours72Moderate.
21
Expressive writingCompleting a brief written emotional expression task over a period of time, like writing an essay that expresses your feeling about a negative, stressful or traumatic experience in your life, and that focuses on how the event related to your life, what coping methods you used and whether these were successfulSmall0.45van Agteren et al. (2021)218> 1,91350%Moderate.
Range in effect size from 0.24 to 0.66 (=0.42)
20 to 80 minutes3High.
22
Promising interventions with a weaker evidence base and a smaller effect size
23
Forgiveness interventionsFollowing a multi-session forgiveness program, in which the potential benefits of forgiveness are emphasized, the development of empathy for the offender is encouraged, and in which emotional regulation, cognitive and behavioral strategies are used to decrease the negative impact of the hurtful interpersonal experience on your lifeSmall0.38Akhtar and Barlow (2018)211> 31850%High.
Range in effect size from 0.29 to 0.48 (=0.19)
2 to 24 hours81Moderate.
24
Reminiscence interventionsReviewing past life experiences, like difficult events or positive memories, notably as part of life review therapySmall0.24Pinquart and Forstmeier (2012)267> 1,083100%Very high.
Range in effect size from 0.22 to 0.31 (=0.09)
About 20 hours83Moderate.
25
Pleasurable experiencesInducing pleasure by writing about three things found pleasurable each day for e.g. one week. This may include things that made you feel happy, experience positive emotions, laugh or feel joy and satisfactionVery small0.17van Agteren et al. (2021)161,095100%Only one effect sizeAbout 1 hour6High.
26
Intervention with no significant effect found
27
Three good thingsWriting and thinking about three things that went well over a period (typically reflecting back on the same day) and reflecting on why those things occurred, repeating this task for a number of days, like a weekVery small0.14van Agteren et al. (2021)1108900%Only one effect sizeAbout 1 hour--
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100