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

Study Overview
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Brief Summary
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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.

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

Conditions
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Cannabis Use Disorder

Intervention / Treatment
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* Behavioral: CANreduce
* Behavioral: psychological support


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CANreduce with psychological support<br>Adherence-focused guidance enhanced web-based self-help for the reduction of cannabis use with psychological support | Behavioral: CANreduce<br>* 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.<br>* Other names: CANreduce: Adherence-focused guidance enhanced web-based self-help for the reduction of cannabis use with psychological support;Behavioral: psychological support<br>* psychological support<br>|
| Experimental: CANreduce without psychological support<br>Adherence-focused guidance enhanced web-based self-help for the reduction of cannabis use without psychological support | Behavioral: CANreduce<br>* 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.<br>* Other names: CANreduce: Adherence-focused guidance enhanced web-based self-help for the reduction of cannabis use with psychological support;|
| No Intervention: Treatment as usual<br>Users will be prompt to a web with a list of the treatment centers nearby their postal code | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the number of days of self-reported cannabis use in the past 30 days (TLFB) | Participants enter their cannabis consumption frequency into their consumption diary every week. More days of self-reported cannabis use indicate worse state | Baseline, 6, 12 and 24 weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the number of days of weekly self-reported cannabis use Time Life Follow Back (TLFB) | Participants enter their cannabis consumption frequency into their consumption diary every week. More days of self-reported cannabis use indicate a worse outcome | Baseline, 6, 12 and 24 weeks. | 
| Change in the quantity of weekly standard joints (TLFB with predifined cannabis standard joints) | Participants enter their cannabis consumption quantity into their consumption diary every week. More number of weekly standard joints indicate a worse outcome | Baseline, 6, 12 and 24 weeks. | 
| Change in the scoring of the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) | 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 | Baseline, 6, 12 and 24 weeks. | 
| Change in the scoring of the Severity Dependence Scale (SDS) | 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. | Baseline, 6, 12 and 24 weeks. | 
| Change in the scoring of the Alcohol Use Disorders Identification Test (AUDIT) | 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 | Baseline, 6, 12 and 24 weeks. | 
| Change in the scoring of the PROMIS Emotional Distress - Depression - Short Form 8b | 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 | Baseline, 6, 12 and 24 weeks. | 
| Change in the scoring of the PROMIS Anxiety 8a - Adult v1.0 | 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 | Baseline, 6, 12 and 24 weeks. | 
| Change in the scoring of the EQ-5D-5L | 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). | Baseline, 6, 12 and 24 weeks. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Web-based Self-Help, Mental health, Adherence, Treatment, Cognitive behavioral therapy