NCT00279604

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).

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
160

participants targeted

Target at P75+ for not_applicable

Timeline
Completed

Started Jul 2005

Typical duration for not_applicable

Geographic Reach
1 country

2 active sites

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

July 1, 2005

Completed
7 months until next milestone

First Submitted

Initial submission to the registry

January 18, 2006

Completed
1 day until next milestone

First Posted

Study publicly available on registry

January 19, 2006

Completed
1.7 years until next milestone

Study Completion

Last participant's last visit for all outcomes

October 1, 2007

Completed
Last Updated

April 20, 2007

Status Verified

April 1, 2007

First QC Date

January 18, 2006

Last Update Submit

April 19, 2007

Conditions

Marijuana Abuse

Outcome Measures

Primary Outcomes (2)

  • Cannabis consumption,

  • motivational change

Secondary Outcomes (1)

  • ASSIST-Score

Interventions

'Problem Profile Intervention' vs. WHO-Brief InterventionBEHAVIORAL

Eligibility Criteria

Age16 Years - 36 Years
Sexall
Healthy VolunteersYes
Age GroupsChild (0-17), Adult (18-64)

You may qualify if:

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

You may not qualify if:

  • 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
  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Friedrich-Wilhelms-University, Department of Psychiatry

Bonn, North Rhine-Westphalia, 53105, Germany

RECRUITING

University of Essen, Department of Psychiatry and Psychotherapy

Essen, North Rhine-Westphalia, 45147, Germany

RECRUITING

MeSH Terms

Conditions

Marijuana Abuse

Condition Hierarchy (Ancestors)

Substance-Related DisordersChemically-Induced DisordersMental Disorders

Study Officials

  • Christian G Schuetz, MD MPH

    University of Bonn, Department of Psychiatry

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Christian G Schuetz, MD MPH

CONTACT

+49 228 287 9664christian.schütz@ukb.uni-bonn.de

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER

Study Record Dates

First Submitted

January 18, 2006

First Posted

January 19, 2006

Study Start

July 1, 2005

Study Completion

October 1, 2007

Last Updated

April 20, 2007

Record last verified: 2007-04

Locations

DE(2)