Randomized controlled trial of interventions for increasing intentional smartphone use and their impact on well-being

There is intense debate surrounding the opportunities and dangers of smartphone use. A substantial literature demonstrates smartphones' associations with a variety of negative outcomes like anxiety and depression, while contrasting literature extols the benefits of smartphones such as increased social connection. Recent research suggests a more nuanced view: that problematic outcomes do not result from use per se, but rather from using smartphones in a habitual, passive, externally-driven manner. Recommendations have been made for how to reduce this problematic use with a variety of smartphone settings changes, but few of these interventions have been empirically tested. Building on a pilot study conducted by the author and colleagues, the current study aims to (1) assess the individual efficacy of several interventions designed to promote more intentional smartphone usage, (2) measure the automaticity of smartphone usage over repeated instances of use with a novel ecological momentary assessment (EMA) paradigm, and (3) examine possible mechanisms of change which may play a role in the observed effects of the interventions. Participants (N = 462) recruited from university classes were randomly assigned to one of five groups and instructed to implement one of the following smartphone settings changes: (1) alphabetize homescreen apps (active control), (2) turn off most notifications, (3) remove all non-tool apps from the homescreen, (4) change the screen to grayscale, (5) concurrently implement the previous three interventions. The intervention period lasted three weeks and was preceded by a three-week baseline period, with objective smartphone usage and EMA data collected throughout. Relative to the active control group, participants in the combined intervention group reported modest reductions in automaticity, Fear of Missing Out (FoMO), and smartphone addiction, whereas the grayscale group demonstrated reductions in weekly smartphone unlocks. The interventions did not appear to be influenced by participants' dispositional levels of mindfulness, self-control, and experiential avoidance, and the effects of the combined interventions on FoMO and smartphone addiction were significantly mediated by reductions in retrospectively rated automaticity. The EMA assessment found that greater automaticity of the prior phone use predicted worse momentary mood, and no treatment significantly impacted momentary automaticity from pre- to post-intervention.