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Completed

NCT Number: NCT04517474

Comparing the Spanish Version of CANreduce With or Without Psychological Support and Treatment as Usual, Reducing Cannabis Use.

Cannabis is the most widely used psychoactive substance around the world after alcohol and tobacco. Although approximately one in ten users develop serious problems of dependency, only a small number attend outpatient addiction counseling centers. CANreduce is an adherence-focused guidance enhanced web-based self-help program with promising results in German and other languages. It also reaches those users who hesitate to approach such treatment centers and help them to reduce their cannabis use.

This study will test the effectiveness of the Spanish version of the enhanced web-based self-help intervention with psychological support, an enhanced web-based self-help intervention (without psychological support) and a waiting list control in reducing cannabis use in problematic users.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Juan-Ignacio Mestre-Pinto

Barcelona, Catalonia, 08003, Spain

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Cannabis use of at least once a week 30 days prior to study entry
  • At least 18 years old
  • At least weekly internet access and a valid email address

Exclusion criteria

  • Participant reports current pharmacological psychiatric disease or history of psychosis, schizophrenia, bipolar type I disorder or significant current suicidal or homicidal thoughts
  • Use of other pharmacological and psychosocial treatments for cannabis use disorders
  • Inability to read or write in Spanish

Treatment and study plan

CANreduce

Behavioral

CANreduce is an automated web-based self-help tool based on classical Cognitive Behavioral Treatment (CBT) approaches for treating cannabis dependence. It will consist of a consumption diary, eight modules designed to reduce cannabis use based on the principles of motivational interviewing, self-control practices, and methods of cognitive behavioral therapy ( strategies for goal achievement, Identifying risk situations, Dealing with cannabis craving, Dealing with relapses, Working on needs, Saying "no" to foster refusal skills, Dealing with burdens, Preserving achievements). Participants can study all modules at their own pace and order, though a specific order will be advised.

Other names: CANreduce: Adherence-focused guidance enhanced web-based self-help for the reduction of cannabis use with psychological support

psychological support

Behavioral

psychological support

Primary outcomes

  1. Change in the number of days of self-reported cannabis use in the past 30 days (TLFB)

    Time frame: Baseline, 6, 12 and 24 weeks.

    Participants enter their cannabis consumption frequency into their consumption diary every week.

    More days of self-reported cannabis use indicate worse state

Secondary outcomes

  1. Change in the number of days of weekly self-reported cannabis use Time Life Follow Back (TLFB)

    Time frame: Baseline, 6, 12 and 24 weeks.

    Participants enter their cannabis consumption frequency into their consumption diary every week.

    More days of self-reported cannabis use indicate a worse outcome

  2. Change in the quantity of weekly standard joints (TLFB with predifined cannabis standard joints)

    Time frame: Baseline, 6, 12 and 24 weeks.

    Participants enter their cannabis consumption quantity into their consumption diary every week.

    More number of weekly standard joints indicate a worse outcome

  3. Change in the scoring of the Cannabis Use Disorder Identification Test - Revised (CUDIT-R)

    Time frame: Baseline, 6, 12 and 24 weeks.

    CUDIT-R was developed containing 8 items, two each from the domains of consumption, cannabis problems (abuse), dependence, and psychological features. It has excellent psychometric properties. High sensitivity (91%) and specificity (90%).

    This questionnaire was designed for self administration and is scored by adding each of the 8 items:

    • Question 1-7 are scored on a 0-4 scale (range 0-28)
    • Question 8 is scored 0, 2 or 4.
    • Score range 0-32 Scores of 8 or more indicate hazardous cannabis use, while scores of 12 or more indicate a possible cannabis use disorder for which further intervention may be required.

    Higher scores indicate a worse outcome

  4. Change in the scoring of the Severity Dependence Scale (SDS)

    Time frame: Baseline, 6, 12 and 24 weeks.

    SDS is a standard instrument to assess the severity to any drug dependence. Each of the five items is scored on a 4-point scale (0-3). The total score is obtained through the addition of the 5-item ratings (0-15). The higher the score the higher the level of dependence.

  5. Change in the scoring of the Alcohol Use Disorders Identification Test (AUDIT)

    Time frame: Baseline, 6, 12 and 24 weeks.

    AUDIT is a 10-item screening tool developed by the World Health Organization (WHO) to assess alcohol consumption, drinking behaviors, and alcohol-related problems. Each item scores 0-4, The total score ranges from 0-40. A score of 8 or more is considered to indicate hazardous or harmful alcohol use. The AUDIT has been validated across genders and in a wide range of racial/ethnic groups and is well suited for use in primary care settings. Higher scores indicate a worse outcome

  6. Change in the scoring of the PROMIS Emotional Distress - Depression - Short Form 8b

    Time frame: Baseline, 6, 12 and 24 weeks.

    PROMIS (Patient-Reported Outcomes Measurement Information System) is a set of person-centered measures that evaluates and monitors physical, mental, and social health in adults and children. It can be used with the general population and with individuals living with chronic conditions. Developed and validated with state-of-the-science methods to be psychometrically sound and to transform how life domains are measured.

    8 items 1-5, score ranges 8-40 Higher scores indicate a worse outcome

  7. Change in the scoring of the PROMIS Anxiety 8a - Adult v1.0

    Time frame: Baseline, 6, 12 and 24 weeks.

    PROMIS (Patient-Reported Outcomes Measurement Information System) is a set of person-centered measures that evaluates and monitors physical, mental, and social health in adults and children. It can be used with the general population and with individuals living with chronic conditions. Developed and validated with state-of-the-science methods to be psychometrically sound and to transform how life domains are measured.

    8 items 1-5, score ranges 8-40 Higher scores indicate a worse outcome

  8. Change in the scoring of the EQ-5D-5L

    Time frame: Baseline, 6, 12 and 24 weeks.

    EQ-5D-5L is a self-assessed, health related, quality of life questionnaire. The scale measures quality of life on a 5-component scale including mobility, self-care, usual activities, pain/discomfort, and anxiety/depression.

    Score ranges from less than 0 (where 0 is the value of a health state equivalent to dead; negative values representing values as worse than dead) to 1 (the value of full health),

    The second part of the questionnaire consists of a visual analogue scale (VAS) on which the patient rates his/her perceived health from 0 (the worst imaginable health) to 100 (the best imaginable health).

Sponsors and collaborators

Lead sponsor

Parc de Salut Mar

Other

Collaborators

  • Research Institute for Public Health and Addiction, Switzerland

Registry information

Official study title

Evaluación de Una Herramienta E-Salud Para la reducción Del Consumo de Cannabis

Acronym: CANREDUCE

Important dates

Study start
2020
Primary completion
2022
Study completion
2022
First posted
Aug 18, 2020
Registry last updated
Sep 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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