Although evidence exists for the efficacy of interventions to prevent depression, little is known about its prevention through online interventions. We aim to assess the effectiveness of online psychological and psychoeducational interventions to prevent depression in heterogeneous populations. A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted based on literature searches in eight electronic data bases and other sources from inception to 22 July 2019. Of the 4181 abstracts reviewed, 501 were selected for full-text review, and 21 RCTs met the inclusion criteria, representing 10,134 participants from 11 countries and four continents. The pooled SMD was −0·26 (95%CI: −0·36 to −0·16; p < 0.001) and sensitivity analyses confirmed the robustness of this result. We did not find publication bias but there was substantial heterogeneity (I² = 72%; 95%CI, 57% to 82%). A meta-regression including three variables explained 81% of the heterogeneity. Indicated prevention and interactive website delivery were statistically associated with higher effectiveness, and no association was observed with risk of bias. Online psychological and psychoeducational interventions have a small effect in reducing depressive symptoms in non-depressed and varied populations, and the quality of evidence is moderate. Given that these types of interventions are very accessible and can be applied on a wide scale, they should be further developed and implemented.

Registration details: Registration number (PROSPERO): CRD42014014804.

尽管有证据表明干预措施可有效预防抑郁症，但人们对通过在线干预措施预防抑郁症的效果知之甚少。我们旨在评估在线心理和心理教育干预措施在预防异质人群中的抑郁症的有效性。从开始到 2019 年 7 月 22 日，基于对 8 个电子数据库和其他来源的文献搜索，对随机对照试验 (RCT) 进行了系统评价和荟萃分析。 在审查的 4181 篇摘要中，选择了 501 篇进行全文审查， 21 项 RCT 符合纳入标准，代表来自 11 个国家和四大洲的 10,134 名参与者。合并的 SMD 为 -0·26（95% CI：-0·36 至 -0·16；p < 0.001) 和敏感性分析证实了该结果的稳健性。我们没有发现发表偏倚，但存在很大的异质性（I ²  = 72%；95% CI，57% 至 82%）。包含三个变量的元回归解释了 81% 的异质性。指示性预防和交互式网站交付在统计上与更高的有效性相关，并且没有观察到与偏倚风险的关联。在线心理和心理教育干预在减轻非抑郁和不同人群的抑郁症状方面效果很小，证据质量中等。鉴于这些类型的干预措施很容易获得并且可以广泛应用，它们应该进一步发展和实施。

注册详情：注册号（PROSPERO）：CRD42014014804。