Table 1. Characteristic of the Included Studies.
| Studies | Sample Size | Markers | Response definition | Responder/Non-responder | Quality assessment | Results |
| Bot et al, 2011 | 149 (M=105; F=44) |
CRP, IL-6, TNFα | Reduction BDI-II ≥ 50% | 73/76 | 5 | No statistically significant differences |
| Fornaro et al, 2011 | 16 (M=4; F=12) |
IL-6 | Reduction HAMD-17 ≥ 50% | 9/7 | 6 | Higher in non-responder (p < 0.05) |
| Chang et al, 2012 | 149 (M=42; F=102) |
CRP | Reduction HAMD-21 ≥ 50% | 64/85 | - | Higher in non-responder (p = 0.020) |
| Fornaro et al, 2013 | 30 (M=8; F=22) |
IL-1β, IL-2, IL-4, IL-10, IL-12, INFγ, TNFα | Reduction HAMD-17 ≥ 50% | 12/18 | 6 | IL-1β higher in responder (p = 0.032) |
| Li et al, 2013 | 61 (M=11; F=50) |
TNFα | Reduction HAMD-17 ≥ 50% | 49/12 | 10 | Higher in non-responder (p < 0.05) |
| Yoshimura et al, 2013 | 118 (M=67; F=51) |
IL-6 | Reduction HAMD-17 ≥ 50% | 62/56 | 7 | Higher in responder (p = 0.031) |
| Uher et al, 2014 | 241 (M=15; F=226) |
CRP | Reduction MADRS ≥ 50% | 120/121 | - | Higher in non-responder to Escitalopram (p = 0.001) |
| Zoga et al, 2014 | 40 (M=0; F=40) |
CRP, TNFα, INFγ | Reduction HDRS ≥ 50% | 40/0 | - | No statistically significant differences |
| Brunoni et al, 2015 | 73 (M=32; F=41) |
IL-2, IL-4, IL-6, IL-10, IL-17, TNFα, INFγ | Reduction MADRS ≥ 50% | 34/39 | - | No statistically significant differences |
| Gupta et al, 2016 | 30 (M=15; F=15) |
TNFα | Reduction HAMD ≥ 50% or HAMD ≥ 7 | 25/5 | 4 | Higher in responder (p < 0.05) |
| Manoharan et al, 2016 | 73 (M=27; F=46) |
IL-6 | Reduction HAMD-17 ≥ 50% | 39/34 | 10 | No statistically significant differences |
| Myung et al, 2016 | 66 (M=16; F=50) |
Eotaxin, sCD40L, MCP-1, IL-8, TNFα | Reduction HAMD-17 ≥ 50% | 40/26 | 8 | No statistically significant differences |
| Ormstad et al, 2016 | 43 (M=8; F=35) |
CRP, IL-1, MIP-1, IL-6, IL-8, TNFα, GM-CSF | Reduction IDS > del 50% | 24/19 | 10 | IL-8 and GM-CSF higher in non-responder (p = 0.027 and 0.034 respectively) |
| Schimdt et al, 2016 | 30 (M=13; F=17) |
IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, GM-CSF, INFγ, TNFα, CRP | Reduction HAMD-17 ≥ 50% | 15/15 | 9 | TNFα, INFγ, GM-CSF, IL-12, IL-10, IL-4, IL-2 higher in responder (all p < 0.05) |
| Gadad et al, 2017 | 94 (M=26; F=68) |
TNFα | QIDS-SR ≥ 8 | 47/47 | 4 | No statistically significant differences |
| Gupta et al, 2017 | 60 (M=25; F=35) |
TNFα | Reduction HAMD ≥ 50% or HAMD ≥ 7 | 54/6 | 5 | No statistically significant differences |
| Hasabe et al, 2017 | 58 (M=19; F=39) |
IL-6, CRP | Reduction MADRS ≥ 50% | 28/30 | 5 | Lower levels of IL-6 correlated with a better response (p = 0.029) |
| Jha et al, 2017 | 106 (M=32; F=74) |
CRP | QIDS-SR < 6 | 45/61 | - | Higher level in non-responder to SSRI monotherapy |
| Milenkovic et al, 2017 | 47 (M=23; F=24) |
Eotaxin1, Eotaxin3, MIP-1α, MIP-1β, MCP-1, MCP-4, MDC, IP-10, TARC | Reduction HAMD-17 ≥ 50% | 31/16 | 8 | No statistically significant differences |
| Mocking et al, 2017 | 70 (M=24; F=46) |
CPR | Reduction HDRS ≥ 50% | 48/22 | - | Higher levels in responder (p = 0.008) |
| Ricken et al, 2017 | 95 (M=38; F=57) |
IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, INF-γ, GM-CSF | Reduction HAMD-17 ≥ 50% | 43/52 | 5 | Higher levels of IL-2 in responder Higher levels of IL-6 in non-responder (all p < 0.05) |
| Brunoni et al, 2018 | 178 (M=60; F=118) |
IL-18, IL-33, IL-1β, IL-6, IL-10, TNFα | Reduction HDRS ≥ 50% | 84/94 | - | No statistically significant differences |
| Chen et al, 2018 | 91 (M=35; F=56) |
INFγ, TNFα, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, GM-CSF | HDRS-21 ≥ 7 | 44/47 | 6 | Higher levels of IL-4 in non-responder |
| Jha et al, 2018 | 166 (M=49; F=117) |
IL-17 | QIDS-SR < 6 | 83/83 | - | Higher level associated with a worse response to SSRI monotherapy |
| Reininghaus et al, 2018 | 87 (M=38; F=49) |
IL-6, CRP | BDI-II > 29 to BDI-II < 14 | 48/39 | 9 | No statistically significant differences |
| Carboni et al, 2019 | 210 (M=74; F=136) |
TNFα, IL-6, IL-10, CRP | Reduction HAMD ≥ 50% | 147/63 | - | Higher levels of IL-10 and TNFα in responder |
| Jun et al, 2019 | 75 (M=26; F=49) |
CRP | Reduction HAMD ≥ 50% | 59/16 | - | Higher levels in non-responder (p = 0.003) |
| Choi et al, 2020 | 1086 (M=490; F=596) |
CRP | HDRS ≥ 7 | 490/596 | 6 | Higher levels in non-responder (p = 0.0027) |
| Fond et al, 2020 | 139 (M=53; F=86) |
CRP | CDSS < 6 | 42/97 | - | No statistically significant differences |
| Jha et al, 2020 | 220 (M=75; F=145) |
CRP | HAMD-17 ≥ 7 | 84/136 | - | Higher levels in female non-responder |
| Kruse et al, 2020 | 40 (M=18; F=22) |
IL-8, IL-6, IL-10, TNFα, CRP | Reduction HAMD ≥ 50% | 20/20 | 5 | No statistically significant differences |