Influence of Tobacco Use on Cannabis Use

Study Overview
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Brief Summary
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Cannabis smokers who also smoke tobacco cigarettes have markedly higher rates of cannabis relapse relative to those who do not use tobacco. There is a clear need to develop and evaluate interventions for dual tobacco and cannabis users. The investigators of this study have previously shown that the co-use of tobacco cigarettes contributes to the maintenance of daily cannabis use, and that age of cigarette onset is a critical predictor of treatment outcome. Short-term tobacco cessation may suffice in altering cannabis relapse rates in later-onset cigarette smokers, while a longer period of tobacco cessation may be needed for earlier-onset smokers. In the current study, a human laboratory model will be utilized to determine whether cannabis relapse varies as a function of tobacco cessation duration and age of tobacco use onset.

Official Title
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Influence of Tobacco Use on Cannabis Use

Conditions
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Cannabis Use, Tobacco Use

Intervention / Treatment
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* Behavioral: 7 days of Tobacco Cessation
* Behavioral: 21 days of Tobacco Cessation
* Drug: Cannabis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and non-pregnant females aged 18-60 years old Use cannabis Smoke tobacco cigarettes Medically and psychologically healthy Exclusion Criteria: Regular drug use other than cannabis Current pregnancy/lactation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The effects of 7- and 21-days of tobacco cessation on cannabis relapse in daily cigarette-smoking, cannabis smokers will be compared, with half the participants in each group initiating tobacco cigarette smoking early (<16 years) and the other half later (>=16 years).
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Early-onset Cigarette Smokers<br>Participants who began smoking cigarettes earlier in life (<16 years old) will be randomized to 7 or 21 days of tobacco cessation. | Behavioral: 7 days of Tobacco Cessation<br>* Participants will be randomly assigned to 7 days of tobacco cessation.<br>* Other names: Early onset;Behavioral: 21 days of Tobacco Cessation<br>* Participants will be randomly assigned to 21 days of tobacco cessation.<br>* Other names: Late onset;Drug: Cannabis<br>* Participants will receive cannabis.<br>|
| Experimental: Late-onset Cigarette Smokers<br>Participants who began smoking cigarettes later in life (>16 years old) will be randomized to 7 or 21 days of tobacco cessation. | Behavioral: 7 days of Tobacco Cessation<br>* Participants will be randomly assigned to 7 days of tobacco cessation.<br>* Other names: Early onset;Behavioral: 21 days of Tobacco Cessation<br>* Participants will be randomly assigned to 21 days of tobacco cessation.<br>* Other names: Late onset;Drug: Cannabis<br>* Participants will receive cannabis.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cannabis self-administration | Number of cannabis cigarettes participant chooses to smoke. | During 9-day inpatient phase |