Comment

The digital placebo effect: mobile mental health meets clinical psychiatry

Many youth experience mental health problems and digital games hold potential as mental health interventions. This systematic review provides an overview of randomised controlled studies assessing the effectiveness of digital applied and casual games for improving mental health in youth aged 6–24 years. A systematic search of PsycINFO, Web of Science and Pubmed yielded 145 eligible studies. Studies on (sub)clinical participant samples (n = 75) most often focused on attention-deficit/hyperactivity disorder (ADHD), autism and anxiety. Applied games were found most effective for improving social skills, verbal memory and anxiety, whereas casual games were found most effective for improving depression, anxiety and ADHD. Studies involving healthy youth (n = 70) were grouped into papers examining anxiety in medical settings, momentary effects on positive and negative affect, and papers employing a longitudinal design measuring mental health trait outcomes. Promising results were found for the use of games as distraction tools in medical settings, and for applied and casual games for improving momentary affect. Overall, our findings demonstrate the potential of digital games for improving mental health. Implications and recommendations for future research are discussed, such as developing evaluation guidelines, clearly defining applied games, harmonising outcome measures, including positive outcomes, and examining nonspecific factors that may influence symptom improvement as well.

Mindfulness apps have become popular tools for addressing symptoms of depression and anxiety. Since the publication of earlier meta-analyses evaluating the efficacy of mindfulness apps for depression and anxiety symptoms, over 20 randomized controlled trials (RCTs) have been conducted. There is a need for an updated meta-analysis that quantifies the effects of mindfulness apps on these symptoms and tests for potential moderators.. Random effects meta-analyses were conducted on 45 RCTs. Small, significant effect sizes were found for symptoms of depression (N_comp = 46, N = 5852, g = 0.24, 95% CI = 0.17, 0.31, NNT = 13.57) and anxiety (N_comp = 48, N = 6082, g = 0.28, 95% CI = 0.21, 0.35, NNT = 11.47) in favour of mindfulness apps over control groups. This effect was not explained by symptom deterioration in participants allocated to control groups. Effects remained stable when restricting analyses to lower risk of bias and larger sample trials. No significant moderators were observed, except trials that offered monetary compensation produced larger effects on depression. Non-significant effects were observed when comparing mindfulness apps to active therapeutic comparisons (g = −0.15 depression, g = 0.10 anxiety), though the number of studies was low. Growing evidence indicates that mindfulness apps can acutely reduce symptoms of depression and anxiety, although higher quality studies with longer follow-ups are needed.

Across a range of age, educational and clinical characteristics, adults experiencing depression and anxiety already use digital technology to manage their symptoms. Although several reviews and meta-analyses indicated feasibility and efficacy for adults with depression and anxiety, digital treatments are poorly accessed and disseminated. This review illustrates potentials and limitations of interventions that specifically leveraged unique features of digital technology and were grounded in the principles of Cognitive Behavioral Therapy (CBT).

This systematic review followed the PRISMA guidelines. An electronic database search was conducted in October 2021. Peer-reviewed, English-language studies were included if i) they reported data from RCTs for adults aged 18+ who engaged with CBT-informed digital interventions targeting primarily depression and anxiety; ii) they used at least PHQ-9 or GAD-7 as standardized and validated assessment self-report measures for depression and anxiety.

Findings from 35 RCTs examining 33 interventions (25 internet-based, 6 mobile-based, a2 mobile/web) are discussed. The quality of the evidence differed widely as many small-scale RCTs reported only short-term feasibility and preliminary efficacy. Effects of CBT-informed digital interventions were substantially larger when compared to waitlist than active control conditions. Greater therapeutic benefits were observed for interventions that offered clinical assistance or were used in combination with other treatments.

CBT-informed digital interventions have accumulated enough scientific evidence to be positioned today as: i) a low-intensity tool for those with subclinical levels of symptoms; ii) a first step in a stepped-care approach to service delivery iii) a low-cost, easily accessible option for targeted preventive programs.