Background: Several studies and meta-analysis suggest that ICBT works for patients with mild to moderate depression/depressive symptoms. Given the quality of the data is is now possible to conduct IPMAs. Several IPMAs have been published with data from different countries. A problem with that approach is the some studies may be left out as data are not provided. The aim of this IPMA was to study the effects focusing on Swedish data only with less loss of data/studies.

Methods: We were able to include data from 16 studies with a total of 2952 participants. Missing data were imputed. The overall effect-size for nine studies compared to wait-list was d = 0.63 95 % CI [0.48, 0.78] and within-group effect-size for 15 studies d = 1.17 95 % CI [1.11, 1.22]. The results were surprisingly similar across different subgroups. Women had on average more symptoms before treatment and also reported a larger symptom decrease after treatment.

Conclusions: Results show a large effect of ICBT on depressive symptoms in a Swedish setting, including in routine care. This meta-analysis supports treatment of depressive symptoms with ICBT in Sweden.