BACKGROUND-AIM:
Youth vaping has risen rapidly across Europe and Cyprus, as in 2019, 17.7% of students across ESPAD countries, and 20.5% in Cyprus, reported e-cigarette use, making e-cigarettes the most commonly used tobacco product among youth. This trend carries substantial risks, including nicotine addiction, lung injury and inflammation, higher respiratory morbidity, and elevated likelihood of initiating and escalating cigarette smoking. Despite calls to action (e.g., U.S. Surgeon General), cessation research for adolescents and young adults remains sparse, with few rigorous trials and limited long-term follow-up. Digital approaches show promise, while the only randomized evaluation to date of a youth/young-adult digital program (This is Quitting) improved 7-month abstinence among quit-ready participants, underscoring the need for engaging, theory-driven tools that also serve users at lower readiness to quit. We present FlexiQuit Vaping, a culturally tailored, smartphone- and SMS-delivered Acceptance and Commitment Therapy (ACT) program for adolescents and young adults (15–29) in Cyprus, designed to engage users across the readiness spectrum.

METHODS:
FlexiQuit Vaping was co-developed with youth and clinical experts to produce a gamified, avatar-guided app with micro-lessons, in-app practice, and supportive messaging. A randomized controlled trial (n=150) is conducted, comparing FlexiQuit Vaping to a control condition (waiting list). Primary outcomes at 6 months include readiness to quit, 24-hour quit attempts and cotinine-verified 30-day point-prevalence abstinence.

RESULTS:
The underlying ACT platform was evaluated with young adults (18–30) in a pilot RCT (n=61), showing strong acceptability (satisfaction 3.8/5) and a higher proportion reporting a 24-hour quit attempt (87.5% in ACT on vaping vs. 75.9% in incentivized text message control). Changes in quit readiness (+0.96 in ACT on vaping vs. +0.72 in control) and cotinine-confirmed 30-day abstinence (4.2% in ACT on vaping vs. 0% in control) favored ACT but were below pre-set efficacy benchmarks, supporting a fully powered trial. Complementing this, a 6-day diary study demonstrated high adherence (9/10 completed all entries), daily session ratings around 4.0–4.3/5, universal willingness to recommend the app, and actionable feedback on avatar design, content depth, and text-message cadence-evidence of strong usability and acceptability to inform refinement.

CONCLUSIONS:
Building on encouraging preliminary findings and user-centered diary insights, FlexiQuit Vaping is evaluated in a larger trial. If effective, it offers a scalable, engaging digital therapeutic to reduce youth vaping and contribute to the Tobacco Endgame strategy.