Reacción a "Reactions: Apps to treat depression could be effective, study review finds"

Although apps in depression have been demonstrating their feasibility, acceptability and satisfaction in successive studies and meta-analyses, there was still some doubt and contradictory aspects about their effectiveness, and if so, for what type of patients, or whether this effectiveness was only limited to apps attached to the usual treatment or also independent ones; whether the effectiveness demonstrated by some studies was due to the design and active controls or not, or whether it had more to do with technical aspects such as notifications or the duration of the treatment. In short, a lot of questions that are crucial in development and studies of the kind we do with apps. The results of this meta-analysis show almost definitively the efficacy of apps in depression, taking into account the target population, the design and methodology of the study, the psychological interventions to be adapted and the notifications, among other aspects. In that sense, they help us to have clearer ideas about these and other aspects, which is of immense guidance in the development, design and execution of studies with apps, at least as far as major depression is concerned. 

Undoubtedly, the study has employed a robust and comprehensive article review and meta-analysis methodology. First, they pre-registered the review in advance, then conducted a detailed and up-to-date review of the main scientific publication databases with up to four reviewers, complemented with standardised bias detection tools and a fairly successful analysis plan to clarify aspects of apps for depression that had not been clear so far in previous meta-analyses. Undoubtedly, the authors have previously made an exhaustive review of the evidence generated so far and have had a comprehensive reading of the aspects that required greater clarity. The selection of inclusion and exclusion criteria as well as the subgroup analyses have also been judicious ensuring that the included studies have assessed the target and clinically relevant population of patients with major depression.  

While the studies included may at first glance be few, it should be noted in the balance that this is on the basis of including patients with unipolar major depression of moderate to severe severity, which is a wise move on the part of the authors, as there is greater assurance that this is the target population and minimises the risk of selection bias. The opposite, i.e. extending the severity criteria to include mild patients, would have helped to include more studies, but would risk leaving the efficacy in depression unclear. However, it is important to bear in mind the inherent limitations of app studies, which lie in the diversity of each app in terms of content and functionality, although the authors did take some of these aspects into account in the sub-analyses by groups according to characteristics. In other words, it should always be remembered that not every app for depression is the same as every other app, especially those that have not been evaluated in clinical trials such as those included in this study.