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Trial registered on ANZCTR

Registration number
Ethics application status
Not yet submitted
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Motivating Behaviour Change in Young Cannabis Users
Scientific title
An investigation into the comparative effectiveness of a brief motivational intervention (BI) and a brief motivational intervention with contingency management (BI + CM) in the treatment of cannabis use in young people over 1, 3, 6 and 12 month follow-ups.
Secondary ID [1] 253605 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cannabis use 261166 0
Condition category
Condition code
Mental Health 259319 259319 0 0

Study type
Description of intervention(s) / exposure
This study aims to determine if the addition of CM to BI improves retention and treatment outcomes, in young people who use cannabis use. We expect young people receiving BI+CM will have better treatment attendance, engagement and completion rates; and improved cannabis use, depressive symptoms and functioning, compared with BI alone, at 1, 3, 6 and 12 months.

Young people who meet inclusion criteria and provide written informed consent to participate in the study will receive a 30-45 minute baseline assessment, administered by a research officer. Once participants have been deemed elligible for inclusion in the study, they will be randomly allocated to either BI or BI + CM. Allocation will be concealed to the research assistant using an opaque sealed envelope.

All participants will receive Quik-Fix, a BI targeting alcohol/cannabis use in young people. They will receive two 1-hour face-to-face sessions (1 x 1hour session per week) of motivational interviewing with a psychologist to: (1) build readiness and commitment to make a change (pros and cons decisional balance); (2) set change goals, and (3) develop a plan for making a change. The intervention is based on the Stages of Change Model, which recommends clinicians focus on increasing the young person’s motivation to make a change (1 above), until the young person is committed to making a change in their alcohol/cannabis use. It also provides brief coping skills training for managing alcohol/cannabis use (looking after yourself, positive event scheduling, stress-less, belly breathing, looking on the bright side).

All participants will be administered a breathalyser and saliva drug test at the beginning of each session. Young people in the BMI + CM condition will receive Quik Fix plus a three-track incentive system to provide high levels of exposure to reinforcement (and protocol treatments) by reinforcing attendance at treatment sessions, abstinence from cannabis use and completion of homework tasks.

1. Attendance: Participants in the BMI + CM condition will receive a $5 gift voucher redeemable for goods and services for attending Quik Fix Session 1 and providing a breathalyser and saliva sample. If they attend Session 2 and provide a breathalyzer and saliva sample, they will receive an additional $5 (total $10) to reinforce treatment attendance and completion.

2. Abstinence from alcohol and drug use: If the specimens (both breathalyser and saliva drug test) the young person provides at Session 1 are drug-free they receive an additional $5 to reinforce abstinence from alcohol and drug use. If the specimens provided at Session 2 are drug-free, the young person will receive an additional $5 (total $10) to increase the likelihood of continued abstinence.

If a participant misses a session, does not provide a breathalyser and saliva drug sample or returns a positive specimen, the value of vouchers is reset back to their original value at the beginning of Session 2 (maximum $5 voucher reinforcement for attending the session and providing a breathalyzer/saliva sample).

3. Homework task: Young people in the CM condition also have access to third incentive system at Session 2 for completing a homework task. They will receive $5 for providing objective evidence (e.g., a photograph) of the completion of an objective, treatment-plan-related homework task that was developed in collaboration with their therapist at the end of Session 1.

The three reinforcement tracks are independent of each other so that the participant is still rewarded for attending sessions even if a positive specimen is returned or a homework task is not completed.

Young people in the BI only condition will receive a $5 gift voucher redeemable for goods and services for attending each session and providing a breathalyser and saliva sample. To control for the reinforcing properties of the dollar value of the voucher reinforcement system in the BI + CM condition, those in the BI only condition will be randomly matched to receive the same dollar value of voucher reinforcement as a participant in the BI + CM condition. Thus, young people in the BI only condition are eligible to receive the same amount of non-contingent voucher reinforcement as those in the BI + CM group.

The research therapists will complete checklists on all sessions. Audiotape ratings will be used to confirm the therapist checklists, and will check that features of non-allocated treatments did not appear. All assessment and treatment sessions will be audio-recorded. An independent psychologist will rate a random selection of 20% of the participants’ treatment sessions for treatment fidelity. Reliability of the baseline research assessments will also be assessed on a random sample of 20% of participants.

An assessor, blind to treatment allocation, will conduct follow-up assessments via telephone at 1, 3, 6 and 12 months post-Baseline. Retention for assessments of >70-80% will be aided by obtaining as many contact methods as possible (fixed phone, mobile, email, address, friend/relative), payment for assessments, and asking if participants ceasing treatment will consent to follow-up. Care will be taken to ensure young people are in an appropriate setting at the time of the telephone consultation with respect to their privacy and confidentiality. Participants will be asked not to divulge information about their treatment, and violations of blind assessment will be recorded. Appointments will be made by phone 2 weeks beforehand, with a reminder at 1 week, 2 days and 1 day before the appointment. Participants will be reimbursed $20 cash for their time and travel-related expenses towards the cost of completing each 30-45 minute research interview. They will receive a total of $100 cash for completing all of the baseline and follow up assessments over the 12 month time period.
Intervention code [1] 258030 0
Treatment: Other
Intervention code [2] 258038 0
Comparator / control treatment
BI only
Control group

Primary outcome [1] 262123 0
Drug Use as measured by the Timeline Followback, the Alcohol, Smoking and Substance Involvement Screening Test, the Severity of Dependence Scale and the Readiness to Change Questionnaire
Timepoint [1] 262123 0
Assessed at Baseline, 1, 3, 6 and 12 months.
Primary outcome [2] 262124 0
Psychological Distress and General Functioning as assessed by the Kessler 10, the Global Assessment of Functioning, the Social and Occupational Functioning Scale, the Modified Vocational Status Index and the Modified Location Code Index; Coping in stressful situations, as measured by the Coping Inventory for Stressful Situations.
Timepoint [2] 262124 0
Assessed at Baseline, 1, 3, 6 and 12 months.
Primary outcome [3] 262125 0
Treatment Engagement and Completion as sessed by number of sessions attended and the Working Alliance Inventory.
Timepoint [3] 262125 0
1 month follwo-up
Secondary outcome [1] 273206 0
Treatment Fidelity as measured by the Yale Adherence and Competence Scale
Timepoint [1] 273206 0
1, 3, 6 and 12 months
Secondary outcome [2] 273212 0
cost effectiveness as measured by the Short Form-12 (SF12) Health Survey and a total health care and a personal cost perspective.
Timepoint [2] 273212 0
1, 3, 6 and 12 months

Key inclusion criteria
Inclusion criteria are: i) aged 16-25; (ii) cannabis use > weekly in the past month. Users of illicit drugs other than cannabis can participate, as can smokers and problem-drinkers, as long as cannabis is most problematic or most frequently used.
Minimum age
16 Years
Maximum age
25 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Exclusion criteria are: (i) unable to speak and read English; (ii) estimated IQ < 80; (iii) history of psychosis, traumatic brain injury, organic brain disease or significant cognitive impairment; or (iv) concurrent psychological treatment for cannabis use or other substance use.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Young people will be recruited by referral from mental health, alcohol and other drug and primary care services as well as school and university settings and media advertising. Young people will be screened for eligibility by telephone by a research assistant and those who meet inclusion criteria will then be provided with a 30-45 minute baseline assessment at QUT. Participants will be randomised to either two sessions of BMI or two sessions of BMI with CM. Allocation will be concealed useing sealed opaque envelopes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computerised random number generation incorporating permuted block randomization techniques will be used to allocate participants to the BMI or BMI + CM. Use of permutated blocks will help to ensure comparable numbers in each condition throughout recruitment, and multiple blocks will help to prevent guessing of allocations by assessors and therapists. Stratification will occur by age (16-21 years, 21-25 years). The research assistants will be blinded to the randomization plan.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 258501 0
Name [1] 258501 0
School of Counselling and Psychology internal grant, Queensland University of Technology
Address [1] 258501 0
Queensland University of Technology
Kelvin Grove Campus
Kelvin Grove QLD 4059
Country [1] 258501 0
Funding source category [2] 258502 0
Name [2] 258502 0
QUT Vice Chancellors Senior Research Fellowship, Queensland University of Technology
Address [2] 258502 0
Queensland University of Technology
Kelvin Grove Campus
Kelvin Grove QLD 4059
Country [2] 258502 0
Primary sponsor type
Other Collaborative groups
Institute of Health and Biomedical Innovation
GPO Box 2434
Brisbane QLD 4001
Secondary sponsor category [1] 257637 0
Name [1] 257637 0
School of Psychology and Counselling, Queensland University of Technology
Address [1] 257637 0
Level 6, B Wing West, O Block
Kelvin Grove Campus
Queensland University of Technology
Kelvin Grove, QLD 4059
Country [1] 257637 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 260477 0
Queensland University of Technology Research Ethics Committee
Ethics committee address [1] 260477 0
Ethics committee country [1] 260477 0
Date submitted for ethics approval [1] 260477 0
Approval date [1] 260477 0
Ethics approval number [1] 260477 0

Brief summary
This study aims to to determine if the addition of contingency management (CM) to a brief motivational intervention (Quik-Fix) improves treatment retention and outcomes in young people who use cannabis. A randomised controlled trial (RCT) will be conducted to compare the mental health, substance use, and functional and treatment outcomes of 40 young people who receive Quik-Fix only to 40 young people who receive the Quik-Fix + CM intervention. Participants will be followed up at 3, 6 and 12 months.

Participants will consist of 80 young people who have used cannabis at least weekly for the previous one month period. Participants will be provided with a two session Quik Fix brief motivational intervention. It is individually administered and incorporates motivational interviewing, and cognitive-behavioural skills delivered within a harm minimisation framework. A three-track incentive CM system will be used to increase participant attendance and abstinence from drug and alcohol use. 40 participants will be allocated to the Quik-Fix only group and 40 will be allocated to the Quik-Fix + CM group. It is hypothesized that young people receiving the Quik-Fix + CM will have reduced substance use, depressive symptom and improved functioning outcomes, as well as improved treatment attendance, completion and attendance, compared to those receiving Quik-Fix only, at 1, 3, 6 and 12 month follow-up.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 32214 0
Address 32214 0
Country 32214 0
Phone 32214 0
Fax 32214 0
Email 32214 0
Contact person for public queries
Name 15461 0
Dr Leanne Hides
Address 15461 0
Institute of Health and Biomedical Innovation
GPO Box 2434
Brisbane, QLD 4001
Country 15461 0
Phone 15461 0
+61 7 3138 6144
Fax 15461 0
+61 7 3138 6030
Email 15461 0
Contact person for scientific queries
Name 6389 0
Dr Leanne Hides
Address 6389 0
Institute of Health and Biomedical Innovation
GPO Box 2434
Brisbane, QLD 4001
Country 6389 0
Phone 6389 0
+61 7 3138 6144
Fax 6389 0
+61 7 3138 6030
Email 6389 0

No information has been provided regarding IPD availability
Summary results
No Results