Internet Program for the Reduction of Cannabis Use

ISRCTN	ISRCTN59948178
DOI	https://doi.org/10.1186/ISRCTN59948178
Secondary identifying numbers	N/A

Submission date: 15/04/2013
Registration date: 23/04/2013
Last edited: 16/10/2015

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Mental and Behavioural Disorders

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English Summary

Background and study aims
Cannabis is the most widely used illegal drug in Switzerland, other Western European countries, Australia and the USA. Most users consume cannabis for recreational purposes, only from time to time or on special occasions. However, some users smoke cannabis more frequently and in higher quantities. These users risk adverse physical and mental health effects. Moreover, there is a certain risk of addiction that can have various psycho-social consequences (like e.g. problems with partner, parents, at work etc.)
in Switzerland and its neighboring countries, treatment for cannabis use disorders like cannabis dependence is mainly provided by outpatient addiction treatment services. For many users these services are difficult to access. Some users also hesitate to get into face-to-face contact as they worry that this could have negative consequences such as stigmatization. In order to improve anonymous treatment and to provide free access to treatment access we have developed the Cannabis Control program.

Who can participate?
Cannabis users aged 18 and above, either sex, and who have smoked cannabis at least once per week in the past 30 days prior to enrolment in the study.

What does the study involve?
Participants will be randomly allocated to one of three groups:
Group 1: Participants will have three individual chat-counseling sessions based on motivational interviewing and cognitive-behavioral therapy approaches in combination with the web-based self-help intervention from Group 2.
Group 2: The web-based self-help intervention is based on classical cognitive behavioral therapy approaches for cannabis addiction, motivational interviewing approaches, and principles of self control.
Group 3: Classical waiting list.
For Group 1 and Group 2, there will be weekly reminder emails to login and fill out a consumption diary. Counseling sessions in Group 1 are provided by trained addiction counselors. Moreover, 8 specific modules to work through in a fixed order but time independent manner will be offered to Group 1 and Group 2. Participants allocated to Group 3 will have the opportunity to participate in the web-based self-help intervention after the follow-up assessment. Follow-up measures will be assessed online and/or by telephone calls three months after enrolment.

What are the possible benefits and risks of participating?
Within the 6 week web-based Cannabis Control program, participants can learn to reduce and control their cannabis use.
Cannabis abstinence or possibly also strong reduction of the frequency and quantity of cannabis may cause withdrawal symptoms or adverse events. In case of serious withdrawal symptoms or adverse events, additional telephone contacts to professionals are provided. Additional costs resulting from these personal contacts are to be covered by the general health insurance that is compulsory for everybody in Switzerland.

Where is the study run from?
The Cannabis Control study has been set up by the Swiss Research Institute for Public Health and Addiction, a World Health Organization Collaborating Center for Substance Abuse, associated institute to Zurich University, Switzerland. The study will be conducted in close collaboration with ARUD, the leading outpatient addiction counseling organization in the Canton of Zurich, Switzerland.

When is the study starting and how long is it expected to run for?
Recruitment in expected to start mid-2013. Participants will be enrolled for a period of two years.

Who is funding the study?
The Swiss Office for the Coordination of Addiction Facilities infodrog (Switzerland).

Who is the main contact?
Dr Michael Schaub
michael.schaub@isgf.uzh.ch

Contact information

Dr Michael Schaub
Scientific

Swiss Research Institute for Public Health and Addiction (ISGF)
Konradstrasse 32
Postfach
Zurich
8031
Switzerland

Study information

Study design	Three arm randomized controlled web-based trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Other
Study type	Treatment
Participant information sheet	Not available in web format, please use the contact details below to request a patient information sheet.
Scientific title	Chat-Counseling and Web-Based Self-Help versus Web-Based Self-Help Intervention versus Waiting List to Control Cannabis Use in Problematic Cannabis Users: A Randomized Controlled Trial
Study acronym	Cannabis Control
Study hypothesis	It is hypothesized, that web-based interventions which are more interactive are more effective in reducing cannabis use in problematic cannabis users. Therefore we will test the following detailed study hypotheses: 1. Chat-based counseling in combination with web-based self-help for the reduction of cannabis use is more effective than the waiting list control condition. 2. Web-based self-help for the reduction of cannabis use is more effective than the waiting list control condition. 3. Chat-based counseling in addition to web-based self-help for the reduction of cannabis use is more effective than web-based self-help alone.
Ethics approval(s)	Ethics Committee of the Canton of Zurich, Switzerland, 11th April 2013, ref: KEK-StV-Nr. 15/13.
Condition	Cannabis misuse and cannabis abuse
Intervention	This is a three arm randomized controlled trial. The intervention in the first arm consists of three individual chat-counseling sessions based on motivational interviewing and cognitive-behavioral therapy approaches in combination with the web-based self-help intervention from study arm two. The web-based self-help intervention from study arm two is based on classical cognitive behavioral therapy approaches for cannabis addiction, motivational interviewing approaches, and principles of self control. The third study arm consists of a classical waiting list. Study arms 1-2 involve weekly reminder e-Mails to login and fill out a consumption diary. Counseling sessions in study arm one are provided by trained addiction counselors. Moreover, 8 specific modules to work through in a fixed order but time independent manner will be offered in study arms 1-2. Participants randomized to the waiting list will have the opportunity to participate in the web-based self-help intervention after the follow-up assessment. Follow-up measures will be assessed online and/or by telephone calls 3 months past registration.
Intervention type	Other
Primary outcome measure	The primary outcome is the quantity of weekly cannabis use (measured in number of predefined average standard joints per week according to a consumption diary).
Secondary outcome measures	1. Number of cannabis use days per week 2. Severity of cannabis use (CUDIT) 3. Severity of cannabis dependence (SDS) 4. Cannabis withdrawal symptoms (CWS) 5. Cannabis craving symptoms (CCS-7) 6. Other psychoactive substance use 7. Brief Symptom Inventory (BSI-18) 8. Health status (EQ-5D-L) 9. Treatment retention 10. Treatment satisfaction
Overall study start date	31/08/2013
Overall study end date	31/08/2015

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	267
Participant inclusion criteria	1. Minimal age 18, either sex 2. At least once a week cannabis use in the past 30 days prior to study entry
Participant exclusion criteria	1. Current serious psychiatric illness or history of psychosis, schizophrenia, bipolar type I disorder or significant current suicidal or homicidal thoughts 2. No other pharmacological or psycho-social treatment for cannabis use disorders at study entry 3. Inability to read or write in German 4. For women: pregnancy or breastfeeding
Recruitment start date	31/08/2013
Recruitment end date	31/08/2015

Locations

Countries of recruitment

Switzerland

Study participating centre

Swiss Research Institute for Public Health and Addiction (ISGF)

Zurich
8031
Switzerland

Sponsor information

Swiss Office for the Coordination of Addiction Facilities - infodrog (Switzerland)
Government

c/o Alwin Bachmann
Eigerplatz 5
Postfach 460
Bern 14
3000
Switzerland

Website	http://www.infodrog.ch
"ROR"	https://ror.org/01qtc5416

Funders

Funder type

Government

Swiss Office for the Coordination of Addiction Facilities - infodrog (Switzerland)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
Publication and dissemination plan	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Protocol article	protocol	14/11/2013		Yes	No
Results article	results	13/10/2015		Yes	No

Editorial Notes

16/10/2015: Publication reference added.