Table 1.
Characteristics of the included studies
| Author, year | Country, continent | Design | Context | Sample size | Mean age ± SD, (range) | Outcome measures | |
|---|---|---|---|---|---|---|---|
| Dispositional optimism | Depression | ||||||
| Chang et al., 2018 | Hungary, Europe | Cross-sectional | Academic | 457 | 21.52 ± 2.16, (18–32) | LOT-R | BDI |
| Chin & Holden, 2013 | Canada, America | Cross-sectional | Academic | 87 | 18.15 ± 0.84, (18–23) | LOR-R | BDI-II |
| Cobb et al., 2020 | United State, America | Cross-sectional | General population | 200 | 21.30 ± 2.09 | LOT-R | CES-D |
| Finch et al., 2020 | Australia, Oceania | Cross-sectional | Academic | 486 | 11.54 ± 1.20. | YLOT | RCADS-SV |
| Guassi & Telzer, 2015 | United State, America | Longitudinal | Academic | 338 | 18.40 ± 0.36 | LOT-R (T1) | CES-D (T1) |
| LOT-R (T1) | CESD (T2) | ||||||
| Heinen et al., 2017 | Germany, Europe | Cross-sectional | Academic | 321 | 21.80 ± 3.93 | SWOP | PHQ-4 |
| Hinkle & Quiton, 2019 | United State, America | Cross-sectional | Academic | 77 | 22.99 ± 6.81 | LOT-R | BDI |
| Iovu et al., 2018 | Romania, Europe | Cross-sectional | General population | 1509 | (18–25) | LOT-R | BDI |
| Jiang et al., 2015 | China, Asia | Cross-sectional | Academic | 1200 | 20.73 ± 1.37 | LOT-R | SDS |
| Kaiser & Malik, 2015 | Pakistan, Asia | Cross-sectional | Academic | 400 | 16.0 ± 1.6, (14–18) | LOT-R | DASS |
| Kapıkıran & Acun-Kapıkıran, 2016 | Turkey, Asia | Cross-sectional | Academic | 494 | 20.85 ± 1.57, (18–30) | LOT-R | BSI |
| Kenny et al., 2016 | Ireland, Europe | Cross-sectional | Academic | 8121 | 20.42 ± 1.90, (17–25) | LOT-R | DASS |
| Kube, Glombiewski, & Rief, 2018 | Germany, Europe | Longitudinal |
Academic Academic |
125 | 22.05 ± 4.00 | LOT-R (T1) | BDI-II (T1) |
| LOT-R (T2) | BDI-II (T2) | ||||||
| Kwok & Gu, 2017 | Hong Kong, Asia | Cross-sectional | Academic | 525 | 13.80, (12–15) | LOT-R | HADS |
| Kwok & Gu, 2019 | Hong Kong, Asia | Cross-sectional | Academic | 302 | 10.56, (9–12) | LOT-R | BSI |
| Liu & Lau, 2013 | United State, America | Cross-sectional | Academic | 670 | 18.92 ± 1.08, (17–22) | LOT-R | CES-D |
| Liu et al., 2017 | China, Asia | Cross-sectional | Academic | 1205 | 19.86 ± 1.26, (17–24) | LOT-R | CES-D |
| Morris et al., 2010 | United State, America | Cross-sectional | Academic | 235 | 18,00 ± 2.00 | LOT-R | CES-D |
| Morton et al., 2014 | Australia, Oceania | Cross-sectional | Academic | 84 | (17–18) | LOT-R | SCAMDA |
| Niu et al., 2018 | China, Asia | Cross-sectional | Academic | 1626 | 14.31 ± 1.52, (12–18) | LOT-R | CES-D |
| O'Sullivan et al., 2019 | Canada, America | Cross-sectional | General population | 886 | 20.7, (18–22) | LOT-R | BDI-II |
| Pinquart & Pfeiffer, 2014 | Germany, Europe | Cross-sectional | Academic | 162 | 16.9 ± 2.6 | LOT-R | CDI |
| Pu et al., 2017 | China, Asia | Cross-sectional | Academic | 535 | 20.67 ± 1.43, (18–23) | LOT-R | SDS |
| Shi et al., 2016 | China, Asia | Cross-sectional | Academic | 2925 | 21.65 ± 1.95, (15–28) | LOT-R | CES-D |
| Tyser et al., 2014 | United State, America | Cross-sectional | Academic | 164 | Age not informed | LOT-R | CDI |
| Wang et al., 2018 | China, Asia | Cross-sectional | Academic | 234 | 18.60 ± 0.78 | LOT-R | BDI |
| Weber et al., 2010 | United State, America | Cross-sectional | Academic | 179 | 15.6, (14-18) | LOT-R | RADS-2 |
| Wong & Lim, 2009 | Singapore, Asia | Cross-sectional | Academic | 334 | 15.6 ± 0.59, (14–18) | LOT-R | CES-D |
| Wu et al., 2015 | China, Asia | Cross-sectional | General population | 50 | 22.2 ± 1.7, (19–25) | LOT-R | BDI-II |
| Xie et al., 2018 | China, Asia | Cross-sectional | Academic | 1742 | 14.35 ± 1.52) | AOS | CES-D |
| Zou et al., 2020 | China, Asia | Cross-sectional | Academic | 652 | 14.55 ± 1.82, (1120) | LOT-R | CES-D |
AOS Adolescents Optimism Scale, BDI Beck Depression Inventory, BDI-II Beck Depression Inventory–II, BSI Brief Symptom Inventory, CDI Children’s Depression Inventory, CES-D Center for Epidemiologic Studies Depression Scale, DASS Depression Anxiety and Stress Scale, HADS Hospital Anxiety and Depression Scale, LOT-R Life Orientation Test-Revised, PHQ-4 Patient Health Questionnaire for Depression and Anxiety, RADS-2 The Reynolds Adolescent Depression Scale, RCADS-SV Revised Children’s Anxiety and Depression Scale–Short Version, SCAMDA Southern Child and Adolescent Mental Health Service Depression and Anxiety Scale, SD Standard Deviation, SDS Self-Rating Depression Scale, SWOP Self-Efficacy, Optimism and Pessimism Instrument, YLOT-R Young Life Orientation Test-Revised