Background: Smartphone apps are an increasingly popular means for delivering psychological interventions to patients suffering from a mental disorder. In line with this popularity, there is a need to analyze and summarize the state of the art, both from a psychological and technical perspective. Objective: This study aimed to systematically review the literature on the use of smartphones for psychological interventions. Our systematic review has the following objectives: (1) analyze the coverage of mental disorders in research articles per year; (2) study the types of assessment in research articles per mental disorder per year; (3) map the use of advanced technical features, such as sensors, and novel software features, such as personalization and social media, per mental disorder; (4) provide an overview of smartphone apps per mental disorder; and (5) provide an overview of the key characteristics of empirical assessments with rigorous designs (ie, randomized controlled trials [RCTs]). Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for systematic reviews were followed. We performed searches in Scopus, Web of Science, American Psychological Association PsycNET, and Medical Literature Analysis and Retrieval System Online, covering a period of 6 years (2013-2018). We included papers that described the use of smartphone apps to deliver psychological interventions for known mental disorders. We formed multidisciplinary teams, comprising experts in psychology and computer science, to select and classify articles based on psychological and technical features. Results: We found 158 articles that met the inclusion criteria. We observed an increasing interest in smartphone-based interventions over time. Most research targeted disorders with high prevalence, that is, depressive (31/158,19.6%) and anxiety disorders (18/158, 11.4%). Of the total, 72.7% (115/158) of the papers focused on six mental disorders: depression, anxiety, trauma and stressor-related, substance-related and addiction, schizophrenia spectrum, and other psychotic disorders, or a combination of disorders. More than half of known mental disorders were not or very scarcely (<3%) represented. An increasing number of studies were dedicated to assessing clinical effects, but RCTs were still a minority (25/158, 15.8%). From a technical viewpoint, interventions were leveraging the improved modalities (screen and sound) and interactivity of smartphones but only sparingly leveraged their truly novel capabilities, such as sensors, alternative delivery paradigms, and analytical methods. Conclusions: There is a need for designing interventions for the full breadth of mental disorders, rather than primarily focusing on most prevalent disorders. We further contend that an increasingly systematic focus, that is, involving RCTs, is needed to improve the robustness and trustworthiness of assessments. Regarding technical aspects, we argue that further exploration and innovative use of the novel capabilities of smartphones are needed to fully realize their potential for the treatment of mental health disorders.

Ample evidence supports the use of Virtual Reality (VR) for anxiety disorders. Nonetheless, currently there is no evidence about moderators or potential negative effects of VR treatment strategies. An Individual Patient Data (IPD) approach was employed with 15 retrieved datasets. The current study sample was composed of 810 patients. Randomized control trials (RCTs) for each primary outcome measure were performed, in addition to moderator analyses of the socio-demographic variables. Deterioration rates were 14 patients (4.0%) in VR, 8 (2.8%) in active control conditions, and 27 (15%) in the WL condition. With regard to receiving treatment, patients in a waiting list control condition had greater odds of deteriorating than in the two active conditions, odds ratios (ORs) 4.87, 95% confidence interval (CI) [0.05, 0.67]. In the case of the socio-demographic variables, none of them were associated with higher or lower odds of deterioration, with the exception of marital status in the WL condition; married people presented a significantly lower probability of deterioration, OR 0.19, 95% CI [0.05, 0.67]. Finally, when comparing pooled effects of VR versus all control conditions, the OR was 0.61 (95% CI 0.31-1.23) in favor of VR, although this result was not statistically significant. This study provides evidence about the deterioration rates of a therapeutic VR approach, showing that the number of deteriorated patients coincides with other therapeutic approaches, and that deterioration is less likely to occur, compared to patients in WL control groups.

Evidence is growing that two modalities of computer-based exposure therapies—virtual reality and computer-aided psychotherapy—are effective in treating anxiety disorders, including fear of flying. However, they have not yet been directly compared. The aim of this study was to analyze the efficacy of three computer-based exposure treatments for fear of flying: virtual reality exposure therapy (VRET), computer-aided exposure with a therapist’s (CAE-T) assistance throughout exposure sessions, and self-administered computer-aided exposure (CAE-SA). A total of 60 participants with flying phobia were randomly assigned to VRET, CAE-T, or CAE-SA. Results indicate that the three interventions were effective in reducing fear of flying at posttreatment and at 1-year follow-up; furthermore, there were no significant differences between them in any of the outcome measure. Large within-group effect sizes were found for all three treatment conditions at both posttreatment and at follow-up. The results suggest that therapist involvement might be minimized during computer-based treatments and that CAE can be as effective as VRET in reducing fear of flying.

Most of the virtual environments currently available in the field of psychological treatments were designed to solve a specific problem. Our research group has developed a versatile virtual reality system (an adaptive display) called ‘EMMA's world’, which can address a wide range of problems. It was designed to assist in clinical situations where a person has suffered a stressful experience, for example post-traumatic stress disorder, adjustment disorder, and pathological grief. To accomplish therapeutic goals, a series of emotional virtual elements are used and personalised so that they are meaningful to the user and contain the fundamental emotional elements that the person must confront. Effectiveness data relating to the system for stress-related disorders are presented.