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Using Implementation Intentions to Reduce Cannabis Use

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ClinicalTrials.gov Identifier: NCT03845842
Recruitment Status : Recruiting
First Posted : February 19, 2019
Last Update Posted : February 19, 2019
Sponsor:
Information provided by (Responsible Party):
Lynsey Gregg, University of Manchester

Brief Summary:
The study will recruit frequent users of cannabis (defined at least fortnightly use) and randomize them either to: (1) form implementation intentions by linking situations in which they are tempted to use cannabis with strategies to avoid using cannabis in those situations by using a volitional help sheet, or (2) to consider the situations in which they are tempted to use cannabis alongside possible strategies to avoid using it as presented in the volitional help sheet but not to form implementation intentions. The effects on self-reported cannabis use will be assessed 1 month post-intervention. Predictors of cannabis reduction will also be examined.

Condition or disease Intervention/treatment Phase
Cannabis Use Behavioral: Volitional help sheet Not Applicable

Detailed Description:

Design: This study will use questionnaires to assess participants cannabis habits (frequency and amount of use) and then employ planning strategies to help them quit. Follow up questionnaires will be used to ascertain the success of planning on reduction in cannabis use.

Sample Size: We plan to recruit a minimum of 60 participants in each condition (120 total) but aim to collect data from as many participants as possible.

Recruitment: To participate in this study a person must be over the age of 18 and a frequent user of cannabis. The study will be advertised online on social media platforms.

Procedure: Potential participants will follow an online link to a briefing sheet that provides information about the study. The sheet will also inform participants that they do not have to complete the questionnaire and that they can withdraw from the study at any time without giving a reason. Once they have read the briefing sheet and generated their personal identity code, as instructed, they will complete the questionnaire online. A month after the participants have completed the initial questionnaire they will receive a link to a follow-up questionnaire via email. Email addresses will be stored separately to study data and will be destroyed once the follow up phase has completed and their involvement in the study ends.

Outcomes and Analysis: The main purpose of this study is to explore the role of planning in encouraging people to reduce cannabis use. Quantitative analysis will be conducted to assess the effects of planning on cannabis use reduction. The investigators expect to find that planning is effective in helping people reduce their use.


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Investigator)
Primary Purpose: Prevention
Official Title: Randomized Controlled Trial of a Volitional Help Sheet in Cannabis Users
Actual Study Start Date : February 14, 2019
Estimated Primary Completion Date : May 31, 2019
Estimated Study Completion Date : May 31, 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Marijuana

Arm Intervention/treatment
Active Comparator: Control (volitional help sheet)
Participants read a brief statement designed to encourage them to reduce their cannabis use ("We want you to plan to reduce your cannabis use"). Participants are presented with a table with two columns and twenty rows. Twenty 'high risk' situations (temptations) are presented in the left hand column and 20 appropriate responses (processes of change) are presented in the right hand column (see Armitage, 2008). Participants are told that identifying situations in which they were tempted to use cannabis and identifying ways to overcome those temptations had been shown to help people change their behaviour and are asked to tick critical situations/appropriate responses that might be useful to them.
Behavioral: Volitional help sheet
Participants are asked to choose from a list of strategies for avoiding cannabis use.

Experimental: Intervention (volitional help sheet)
Participants read a brief statement designed to encourage them to reduce their cannabis use ("We want you to plan to reduce your cannabis use"). Participants are presented with a table with two columns and twenty rows. Twenty 'high risk' situations (temptations) are presented in the left hand column and 20 appropriate responses (processes of change) are presented in the right hand column (see Armitage, 2008). Participants are told that identifying situations in which they were tempted to use cannabis and identifying ways to overcome those temptations had been shown to help people change their behaviour. Implementation intentions are formed by linking critical situations with appropriate responses by choosing an appropriate response from a drop down menu for each critical situation.
Behavioral: Volitional help sheet
Participants are asked to choose from a list of strategies for avoiding cannabis use.




Primary Outcome Measures :
  1. Cannabis use reduction (amount) [ Time Frame: 1 month ]
    Self-reported cannabis use -amount of cannabis (weight)

  2. Cannabis use reduction (frequency) [ Time Frame: 1 month ]
    Self-reported cannabis use - frequency of use (days per week)


Secondary Outcome Measures :
  1. Self reported habit as measured by the automaticity subscale of the Self-Report Habit Index. [ Time Frame: 1 month ]
    Self-reported habit (e.g., "Using cannabis is something I do automatically: strongly agree - strongly disagree).

  2. Self reported action control as measured by the scale developed by Sniehotta et al (2011) [ Time Frame: 1 month ]
    Self-reported action control (e.g., "During the last week I often had my intention to reduce my cannabis use on my mind: strongly disagree-strongly agree")

  3. Self reported craving as measured by items from the mood and physical symptoms scale (MPSS) [ Time Frame: 1 month ]
    self reported craving



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Frequent cannabis user (at least fortnightly)

Exclusion Criteria:

  • Younger than 18 years of age
  • Infrequent / no cannabis use (less than fortnightly)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03845842


Contacts
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Contact: Lynsey Gregg, PhD 01612758486 lynsey.gregg@manchester.ac.uk
Contact: Chris Armitage, PhD 01613066000 chris.armitage@manchester.ac.uk

Locations
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United Kingdom
The University of Manchester Recruiting
Manchester, United Kingdom, M13 9PL
Contact: Lynsey Gregg, PhD    01612758486    lynsey.gregg@manchester.ac.uk   
Contact: Chris Armitage, PhD    01613066000    chris.armitage@manchester.ac.uk   
Sponsors and Collaborators
University of Manchester
Investigators
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Principal Investigator: Lynsey Gregg, PhD The University of Manchester

Publications:
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Responsible Party: Lynsey Gregg, Principal Investigator, University of Manchester
ClinicalTrials.gov Identifier: NCT03845842     History of Changes
Other Study ID Numbers: 2018 5701
First Posted: February 19, 2019    Key Record Dates
Last Update Posted: February 19, 2019
Last Verified: February 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Lynsey Gregg, University of Manchester:
Cannabis
Risk reduction
Additional relevant MeSH terms:
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Marijuana Abuse
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders