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INCA - Intervention and Neuropsychology in Cannabis Abuse

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00279604
Recruitment Status : Unknown
Verified April 2007 by University Hospital, Bonn.
Recruitment status was:  Recruiting
First Posted : January 19, 2006
Last Update Posted : April 20, 2007
German Federal Ministry of Education and Research
Information provided by:
University Hospital, Bonn

Tracking Information
First Submitted Date  ICMJE January 18, 2006
First Posted Date  ICMJE January 19, 2006
Last Update Posted Date April 20, 2007
Study Start Date  ICMJE July 2005
Primary Completion Date Not Provided
Current Primary Outcome Measures  ICMJE
 (submitted: September 7, 2006)
  • Cannabis consumption,
  • motivational change
Original Primary Outcome Measures  ICMJE Not Provided
Change History Complete list of historical versions of study NCT00279604 on Archive Site
Current Secondary Outcome Measures  ICMJE
 (submitted: September 7, 2006)
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE INCA - Intervention and Neuropsychology in Cannabis Abuse
Official Title  ICMJE Targeted Interventions in Cannabis Abuse: Focus on Decision Making (INCA)
Brief Summary INCA (Intervention and Neuropsychology of Cannabis Abuse) is a study combining two research goals. One is to study efficacy of a short intervention the ‘Problem Profile Intervention’, which utilizes individual feedback from a ‘substance problem check-up’. Subjects will randomly receive the ‘Problem Profile Intervention’ or the WHO Brief Intervention, a brief intervention, which has been shown to be efficacious. Currently efficiency studies are under way. The WHO Brief Intervention has been translated into German by our group. In contrast to most other cannabis intervention studies the current study is focussed on cannabis abusers not so much cannabis-dependent subjects. A total of 160 subjects are to be recruited. Half of them will randomly receive either the Problem Profile Intervention or the WHO Brief Intervention (active control). A total of 25% of subjects from each group will be placed on a 3 months waiting list before receiving the intervention (inactive control). Intervention outcome will be assessed three months, six month and 12 months after the intervention. We hypothesize cannabis use to be reduced by 25% by the 'Problem Profile Intervention'. The second aim of the study is to study mechanism of substance abuse. Initial results from own studies and data from other groups point to executive cognitive functions as a subtle but important factor that can be compromised in cannabis users (Verdejo-Garcia et al., 2004; Garavan and Stout, 2005). Using an fMRI-study, we intend to examine a subgroup of our subjects on a specific aspect of executive functioning that has recently received major interest in drug research: Decision-making capability, or risk-taking behaviour, respectively (e.g. Ernst and Paulus, 2005).
Detailed Description Not Provided
Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Condition  ICMJE Marijuana Abuse
Intervention  ICMJE Behavioral: 'Problem Profile Intervention' vs. WHO-Brief Intervention
Study Arms  ICMJE Not Provided
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Unknown status
Enrollment  ICMJE
 (submitted: January 18, 2006)
Original Enrollment  ICMJE Same as current
Estimated Study Completion Date  ICMJE October 2007
Primary Completion Date Not Provided
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • ASSIST-Score for cannabis consume ≥ 4 ≤ 26
  • german mother tongue (or comparable level)

Exclusion Criteria:

  • major current psychiatric disorder (e.g. psychosis)
  • addiction to other illegal drugs or alcohol
  • recent or current intravenous drug use
  • CNS-affecting medication
  • current psychotherapy, other treatment for substance use disorder

exclusion criteria for fMRI-part:

  • left-handedness
  • medication (birth control pill, thyroid gland hormones possible)
  • internistic illnesses (hypertension, diabetes, diseases of lungs)
  • metallic implants (cardiac pacemaker, ferromagnetic object implanted through surgical intervention or accident, large-area tattoos)
  • history of serious trauma
  • claustrophobia
  • gestation
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 16 Years to 36 Years   (Child, Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE Germany
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT00279604
Other Study ID Numbers  ICMJE 01EB0432
Has Data Monitoring Committee Not Provided
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Not Provided
Study Sponsor  ICMJE University Hospital, Bonn
Collaborators  ICMJE German Federal Ministry of Education and Research
Investigators  ICMJE
Principal Investigator: Christian G Schuetz, MD MPH University of Bonn, Department of Psychiatry
PRS Account University Hospital, Bonn
Verification Date April 2007

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP