Reducing smartphone overuse for adolescents with attention-deficit hyperactive disorder: study protocol for a randomized controlled trial.

BACKGROUND: Smartphone overuse (SO) is pervasive and is detrimental to individuals' quality of life, physical and mental health, and academic/career achievements. Attention-deficit hyperactivity disorder (ADHD) diagnosis and traits are consistently identified as risk factors of SO. Studies revealed that SO interventions can bring about large positive effects on SO, yet there is no published SO intervention for clinically-diagnosed ADHD individuals using a randomized controlled trial (RCT) design. Moreover, very few studies investigated ADHD symptoms and neural correlates of SO as outcome measures of SO interventions. The overall aim of the proposed study is to develop and evaluate a smartphone-based behavioral and individualized intervention for adolescents with ADHD and SO in Hong Kong. METHOD: We will implement a behavioral smartphone-based RCT intervention with two parallel groups of clinically diagnosed ADHD adolescents with SO in Hong Kong. A total of 120 adolescents with ADHD will be recruited. The intervention group will receive a 12-week individualized behavioral intervention with weekly reminders, implementing specific strategies that counter the potentially addictive qualities of smartphones using built-in smartphone functions. The control group participants will self-monitor their smartphone usage. During the intervention phase, participants will be contacted once a week to collect the objective smartphone use patterns. Both groups will be measured on smartphone dependence and ADHD symptoms, and resting-state electroencephalogram (EEG) signals under the smartphone salient vs. smartphone non-salient conditions will be recorded. Parents need to report children's ADHD symptoms. These outcomes will be measured three times: [1] one week before the intervention [2], one week after the intervention, and [3] nine months after the intervention. Greater sustained reduction in self-reported smartphone dependence and objective smartphone usage, self and parent-rated ADHD symptoms, and spectral power differences in resting-state EEG in the two conditions will index intervention effects among adolescents with ADHD. DISCUSSION: The study results will contribute to the evidence-based practice of SO intervention, providing an intuitive and cost-effective solution. Establishing a causal relationship between the reduction of SO and ADHD symptoms is important for informing the nosology of SO. Furthermore, the findings will contribute not only to the local evidence base but the global discussions around the issue of SO. TRIAL REGISTRATION: ClinicalTrials.gov (NCT07092787). Registered July 21, 2025.