Approximately 50% of persons seeking treatment for cannabis-use disorders (CUDs) regularly smoke tobacco. Combining tobacco with cannabis has become a common method of smoking cannabis. Similarities of use, and using together, can make quitting difficult. Stopping tobacco simultaneously with cannabis may be beneficial. Little scientific information currently addresses how to best target tobacco smoking during treatment for CUDs. Our long-term goal is to develop an effective protocol for intervening in tobacco smoking without changing cannabis outcomes.

This protocol reflects the planned Stage 1, proof-of-concept study that will compare a combined cannabis and tobacco intervention to one that targets CUD only. Hypotheses assert that the intervention (1) will be accepted by the majority of eligible participants (2) will result in more tobacco quit attempts and rates than the CUD-only treatment; and (3) will not adversely affect cannabis outcomes. Last, the project will evaluate the potential of specific moderators of outcomes to predict outcomes and inform subsequent treatment development efforts. If the hypotheses were confirmed, dissemination of this protocol would reduce adverse psychosocial and health consequences of tobacco or cannabis dependence. Findings will inform future development of prevention and intervention strategies.

Inclusion Criteria:

1. Individuals must be 18 years or older
2. Individuals must meet criteria for the current Diagnostic and Statistical Manual -IV diagnosis of cannabis abuse or dependence, report use of cannabis on at least 45 of the previous 90 days, and report regular use of tobacco cigarettes or report that their primary administration of cannabis is via blunts or spliffs
3. Individual must indicate that they have at least some interest in quitting tobacco in the next 6 months (rating of 2 or more on a 5-point interest scale)

Exclusion Criteria:

1. Current dependence on alcohol or any drug other than tobacco and cannabis
2. Use of non-tobacco nicotine
3. Current participation in structured treatment for substance abuse
4. Severe psychological distress (e.g., active suicidal plans, psychosis, debilitating panic disorder)
5. Report of a condition that requires seeing a physician before using NRT (e.g., pregnancy or recent heart attack); note: if a participant's physician approves taking NRT, we will consider enrolling them
6. Legal status that would interfere with participation
7. Living with someone currently enrolled in the project
8. Not being fluent in English
9. Not living within 45 miles of the research site

Two years

Enrollment did not meet planned target numbers, limiting the power to detect differences between conditions.