The REWIRE Behaviour Study

The REWIRE study is a two-phase, interventional trial designed to evaluate the feasibility, mechanistic underpinnings, and clinical effects of a structured social media use (SMU) reduction program combined with reinforcement of individualized, non-screen alternative behaviours in adolescents experiencing emotional distress. The study is grounded in behavioural economic principles, family-based treatment (FBT) models, displacement theory, and social comparison theory, and integrates multimodal behavioural, cognitive, and neuroimaging methodologies.

Adolescence represents a developmental window characterized by heightened sensitivity to social reward, ongoing maturation of prefrontal regulatory systems, and increased vulnerability to anxiety and depressive disorders. Converging behavioural and neuroimaging evidence suggests that heavy SMU engages neural circuits implicated in reward processing (e.g., ventral striatum), socio-emotional reactivity (e.g., amygdala), and self-referential processing (e.g., medial prefrontal cortex and default mode network). Experimental studies in adults indicate that restricting SMU can reduce symptoms of anxiety and depression; however, existing studies have been limited by short intervention durations, reliance on self-reported adherence, and lack of mechanistic evaluation in youth populations.

REWIRE addresses these gaps by implementing a 12-week behavioural intervention with objective monitoring of SMU, integration of family-based reinforcement strategies, and examination of neurocognitive and neural correlates of behavioural change.

This study uses a two-phase design:

Phase 1 (Pilot Feasibility Phase):

A single-arm pilot involving approximately 10 youth-caregiver dyads to evaluate recruitment feasibility, adherence to the SMU reduction target, usability of procedures (e.g., daily screenshot submission, ecological momentary assessment [EMA] completion), and acceptability of intervention components. Findings from Phase 1 will inform procedural refinements prior to initiation of the randomized controlled trial (RCT).

Phase 2 (Randomized Controlled Trial):

A balanced, parallel-group RCT enrolling approximately 100 youth-caregiver dyads. Participants are randomized 1:1 using computer-generated block randomization implemented through REDCap by the CHEO Clinical Research Unit. Participants are blinded to study hypotheses and are informed that two youth mental health programs are being compared.

Both phases include a 1-week baseline monitoring period followed by a 12-week intervention/control period (13 weeks total participation).

REWIRE Intervention Arm The intervention consists of a structured, manualized, family-based behavioural therapy program delivered over 12 weeks. Youth and caregivers attend separate weekly 30-minute in-person group sessions led by trained research staff under clinical supervision. In addition, youth receive individualized 15-minute weekly goal-setting and progress-review sessions.

The intervention targets:

• SMU Reduction to 50% of Baseline:

Baseline SMU is calculated using 7-day objective smartphone usage data. The 50% reduction target is standardized relative to each participant's baseline, ensuring individualized but proportionally equivalent behavioural goals.

• Reinforcement of Individualized Alternative Behaviours:

Substitute behaviours are selected based on baseline assessment of behavioural preferences (Pleasant Events Schedule) to maximize reinforcing value and substitutability. Activities may include in-person social interaction, physical activity, hobbies, creative engagement, sleep hygiene, volunteering, and outdoor activities.

• Behavioural Modification Techniques:

Intervention strategies are adapted from empirically supported FBT frameworks and include:

• Stimulus control (e.g., disabling notifications, device-free bedroom rules)
• Contingency management and reinforcement schedules
• Behavioural contracting
• Parental modelling and structured support
• Problem-solving and barrier identification
• Realistic, graduated goal setting

Caregivers act as behavioural change facilitators, consistent with FBT evidence demonstrating superior maintenance of lifestyle behaviour changes when caregivers are actively engaged.

Participants receive a structured REWIRE workbook outlining psychoeducation regarding screen overuse, behavioural regulation strategies, and structured routines.

Psychoeducation Control Arm The control arm receives an attention-matched, 12-week psychoeducation program delivered in weekly in-person group sessions. Content focuses on general education regarding social media, screen time, lifestyle behaviours, and mental health, but does not include behavioural modification strategies, reduction targets, or reinforcement protocols.

Both arms engage in equivalent monitoring procedures (daily screenshot submission, EMA reporting, accelerometry), controlling for expectancy effects, self-monitoring effects, and staff contact time. This design provides a more stringent comparison than waitlist controls.

Throughout the 12-week intervention period, participants:

• Upload daily screenshots of smartphone app usage from all devices.
• Complete brief daily EMA surveys assessing sleep duration, leisure activities, accelerometer wear compliance, and non-captured screen use.
• Wear a wrist-worn accelerometer during waking hours to objectively quantify physical activity and sedentary behaviour.
• This multimodal monitoring approach enhances adherence fidelity and minimizes recall bias.

Participants complete the NIH Toolbox Cognition Battery at baseline, mid-intervention, and post-intervention to assess executive function, attention, working memory, processing speed, episodic memory, and language. These data support exploratory brain-behaviour correlation analyses linking cognitive performance to neural and behavioural changes.

The study is designed to evaluate potential mediators and moderators of treatment response.

Mechanistic pathways include:

• Displacement of sedentary screen time by sleep, physical activity, and in-person social engagement
• Reduction in maladaptive social comparison
• Changes in the reinforcing efficacy of social media
• Enhanced executive control and emotional regulation

Moderation analyses will explore whether intervention effects vary by:

• Gender
• Baseline distress severity
• Household income
• Social media disorder symptoms
• Intervention adherence

Participants are blinded to group allocation and study hypotheses. Randomization is centralized and automated. Data are entered and analyzed using coded identifiers. Both arms receive equal session frequency and monitoring demands to minimize expectancy and contact biases.

Qualitative exit interviews (randomly selected subset of participants) are analyzed using the Theoretical Domains Framework (TDF) to identify behavioural determinants influencing adherence and implementation feasibility. Interviews are transcribed verbatim and coded independently by two analysts using NVivo software.

REWIRE is among the first randomized controlled trials to examine sustained SMU reduction in adolescents with emotional distress using objective adherence measures, family-based behavioural reinforcement, and multimodal neuroimaging assessment. By integrating behavioural economics, developmental neuroscience, and family-based intervention principles, this study seeks to determine whether modifying digital behaviour can produce measurable improvements in mental health, cognitive function, and neural circuitry.

If effective, REWIRE may represent a scalable, low-cost, interim intervention within stepped-care youth mental health models, particularly for adolescents facing prolonged wait times for conventional services.

Inclusion criteria

• Own a smartphone.
• Use social media for >3 hours/day.
• Are aged 12-17 years.
• Are experiencing feelings of anxiety or depression.
• Have a caregiver who is able and willing to participate in the study alongside them.
• Have the ability to communicate in English.
• Must sign and date the informed consent form, or provide assent and have a Substitute Decision Maker provide informed consent

Exclusion criteria

• Own a smartphone.
• Use their smartphone for >1 hour/day.
• Are accompanying a youth participant enrolled in the study.
• Have the ability to communicate in English.
• Are willing to sign informed consent forms.