After over a year of work, GEOTEC is happy to announce the publication of a large-scale systematic review on the use of smartphone applications for the treatment of mental disorders. The study examined over 13.000 articles, published in the time period 2013 – 2018, to come to a final set of 158 that deal with smartphone apps to treat mental disorders.  This review is a collaboration between the GEOTEC and LABPSITEC, a psychology research group at UJI, within the context of the SYMPTOMS project.

These 158 articles were subsequently analysed from a psychological and from a technical point of view. In the psychological dimension, we determined which mental disorder was addressed, which type of assessment was performed, and for the articles applying a (Pilot) Randomized Controlled Trial (RCT), the psychological approach applied, study design, sample and experimental conditions. In the technical dimension, we studied the applied software features (e.g., learning, progress, personalisation, prompting, …), the sensors  used and advanced analytics applied (e.g., machine learning, activity, spatial and behavioural analysis). The quantitative results of this analysis was plotted in a bubble chart, whereby each bubble represents the amount of articles in which a technical feature is used for a particular mental disorder. Complementing the published article, we have created a dashboard to allow readers to interactively explore the review results. 

The main highlights from this analysis can be summarised as follows (figure 1):

• The most covered technical dimensions are software features, with learning, progress indication, personalisation, mental health assessment, prompting, health care provider communication and in-situ use.
• Sensors and advanced analytics were significantly less used, with microphone, GPS and camera the most popular sensors, and machine learning and activity analysis the most used advanced analytics.-
• The most covered mental disorders are depressive disorders, various disorders, anxiety disorders, substance-related and addictive disorders, schizophrenia spectrum and other psychotic disorders, and trauma and stressor-related disorders.

From the temporal and assessment analysis, conclusions can be summarised as follows (partly in figures 2 and 3):

• There is an increasing attention for the use of smartphone apps for mental health interventions over the years, from 7 published articles in 2013 to 60 in 2018.
• Collectively, the top six mental disorders account for 73.4% (116/158) of all studies included in the search. Depressive disorder is most addressed, with 19,6% of articles.
• 28,5% of articles present no assessment. Assessment towards effect is done in a minority of cases (13,9%), against 25,3% for usability and user experience type of assessment. The remaining articles (32,3%) present a mixed assessment (effect & usability/UX).
• 20% of the articles presented a Pilot RCT or RCT. The majority of RCTs use the Cognitive Behavioural Therapy (CBT) psychological framework, possibly combined with third wave therapy techniques. The majority of RCTs showed that participants who received the intervention app significantly improved their symptoms.

Based on our findings, we formulate four recommendations for researchers in the field:

• Attention for less covered disorders: The majority of research (approximately 73%) pertains to the top six covered mental disorders, four of which coincide with highly prevalent mental disorders. On the other hand, more than half of the DSM-5 mental disorders are not or very scarcely covered. We call upon the research community to invest into covering the full breadth of mental disorders.
• Attention for advanced technical and software-based solutions: current research generally does not fully exploit smartphones’ advanced technical capabilities. Concretely, the use of sensors and corresponding context awareness, particularly to promote Ecological Momentary Interventions, the exploration of alternative delivery paradigms such as virtual or augmented reality, and advanced analytical methods are scarcely investigated. We call upon the research community to explore beyond traditional strategies, toward leveraging advanced technological features to improve mHealth interventions
• Multidisciplinary approaches: To fully exploit the smartphone’s capability as a pervasive, ubiquitously connected, sensor-packed computing platform to deliver innovative, real-time, and in situ psychological interventions, both the domain knowledge of psychologists and the technical expertise of computer scientists are needed. Hence, we call for multidisciplinary collaborations as to not let technical difficulties, or lack of psychological knowledge on mental disorders, hinder advances and novelties in the field.
• Validation toward effect: There exists a need to rigorously validate smartphone-based psychological treatments for effect. Especially when utilising advanced technical features (eg, context awareness, analytics, and alternative delivery paradigms), effect validation may increase trust and spark further research in such novel types of interventions. We call upon the research community to augment efforts in rigorous effect assessment, to allow transfer of research into practice.

A deeper analysis and discussion of the results can be found in the article:

Miralles I., Granell C., Díaz-Sanahuja L., Van Woensel W., Bretón-López J., Mira A., Castilla D., Casteleyn S. (2020) Smartphone Apps for the Treatment of Mental Disorders: Systematic Review, JMIR Mhealth Uhealth 2020;8(4):e14897, DOI: http://doi.org/10.2196/14897