Clinical practice guidelines for smoking cessation emphasize cognitive behavioral therapy (CBT) to help patients develop coping strategies for urges. Mindfulness or Acceptance and Commitment Therapy (ACT) offer a different approach, which teaches smokers psychological flexibility through accepting negative experiences. While there is evidence for the efficacy of both CBT and Mindfulness/ACT smoking cessation interventions, it is unclear if these approaches are efficacious when implemented in real-time and with young adults. The overall goal of this proposal is to evaluate the efficacy of CBT and Mindfulness/ACT messages for young adults targeted at specific high-risk situations for smoking.

This research will address the following specific aims:

Aim 1: To test CBT and Mindfulness/ACT intervention message efficacy for reducing momentary smoking urges (N=80). To inform just-in-time interventions, it is crucial to test if CBT and Mindfulness/ACT based messages can reduce momentary smoking urges. The investigators will conduct a micro-randomized trial (repeated within-subject randomizations of messages) to accomplish this. In line with the investigators' existing protocol, participants first collect Ecological Momentary Assessment (EMA) data for 14 days, allowing the investigators to determine high-risk situations for smoking. In the following intervention phase, participants receive tailored messages triggered by geofencing of participants' high-risk locations for a total of 30 days. Tailoring is based on established predictors of smoking relapse (stress and presence of other smokers). The micro-randomized trial tests the efficacy of CBT versus Mindfulness/ACT versus control messages for reducing smoking urge 15 minutes post message delivery. Secondary outcomes include smoking or other tobacco use (including e-cigarettes), affect, and stress.

Aim 2: To test if exposure to urge reduction messages results in changes in smoking behavior over time compared to an EMA only control group (N=80). It is important to investigate if repeated messages in the micro-randomized trial impact smoking behavior over time, in contrast to just repeated assessment without messages. Thus, this study includes a conventionally randomized clinical-trial component. Parallel to the micro-randomized trial group, a control group completes EMA surveys only without intervention messages. This allows the investigators to test if messages reduce smoking behavior. The primary outcome is number of cigarettes per day at end of treatment, 3-, and 6-months follow-up. Secondary analyses explore biochemically verified 7-day point prevalence abstinence, switching to e-cigarettes, and other tobacco outcomes. Post-hoc dose-response analyses investigate the long-term efficacy of CBT or Mindfulness/ACT messages on smoking behavior.

Aim 3: Explore moderation effects of substance co-use (cannabis, alcohol, other drugs) and exposure to specific location (home, work, bars) on urge reduction message efficacy. A crucial research question to inform future mobile interventions is how well intervention messages work in different situational contexts and when people are co-using other substances. Among intervention group participants, the investigators will explore how urge reduction message efficacy may be moderated by substance co-use and exposure to specific settings.

Inclusion Criteria:

1. live in the U.S.
2. read English;
3. are between 18 and 30 years of age;
4. own an iPhone or Android smartphone;
5. have smoked ≥100 cigarettes in their lives and currently smoke at least 3 cigarettes per day on 5 or more days of the week;
6. are planning to quit smoking within the next 30 days.

Exclusion Criteria:

• None

Any individual requests for data will be honored on a case-by-case basis as deemed appropriate to the research protocol.