Implementation of the CANDIS targeted therapy for cannabis disorders in the German outpatient addiction treatment system

Funding: Ministry of Health

Contributors: PD Dr. Eva Hoch (head of project), Dipl.-Psych. Anja Pixa, Dipl. Psych. Katrin Dittmer, Dipl. Psych. Anne Rühlmann, Dipl.-Stat. Dr. Michael Höfler, Prof. Dr. Gerhard Bühringer, Prof. Dr. Hans-Ulrich Wittchen.
Duration: 2007 – 2010


CANDIS is a modular withdrawal programme for adolescents (> 16 years) and adults with problematic cannabis use. It was developed during the years 2004 – 2007 at the Institute for Clinical Psychology & Psychotherapy, Technical University Dresden, and was successfully tested in a randomised-controlled study. Within the scope of a transfer study it was examined if this approach is also applicable and effective in outpatient addiction treatment settings.


1. Transfer of the CANDIS Therapy into routine treatment

Prior to begin of the study, interested outpatient addiction treatment centres from all over Germany could apply for participation. Out of 50 applications 11 settings from the towns Bautzen, Berlin (2 x), Braunschweig, Dresden, Hamburg, Hannover, Munich, Münster, Osnabrück and Stuttgart, were selected according to defined textual criteria (e. g. existing treatment documentation, training certificates of the scheduled study therapists in behavioural therapy, number of cannabis cases during the last year, regular implementation of urine controls, existing video equipment and consent for the details of the study). Following, two therapists per each study centre were trained to implement the therapy and conducted manualised treatments in accordance with the programme on patients of their settings included in the study during the whole recruitment period (May 2008 – April 2009). They were also responsible for the extensive scientific accompanying documentation as well as implementation of the catamneses in their settings.

2. Proof of efficacy of the CANDIS programme

In order to test its efficacy under real practice conditions, a multi-centric randomised-controlled intervention study was carried out. Adolescents (> 16 years) and adults with problematic cannabis use were assigned randomly to either active study conditions (standardised single therapy ST; target n=150) or the waiting group (WG; target n=150). Patients of the waiting group could start treatment after a waiting period of 8 weeks. Primary result variable was “abstinence”, secondary result variable was “reduced consumption” during the last 28 days. Result documentation was done by study therapists during first interview prior to therapy start, in sessions 1 – 10, during final interview as well as in the catamneses three and six months after treatment start. For reassurance of the content and quality of treatment, all therapy sessions in the addiction treatment centres were recorded via video recorder. Monitoring of manual adherence was done routinely at the study centre in Dresden. All study therapists were informed on the quality of therapy implementation.

3. Evaluation of chances and barriers of practice transfer

Transfer of the CANDIS therapy into outpatient addiction treatment was to be documented via process evaluation. By using questionnaires, all n=22 study therapists were interviewed (e. g. therapy acceptance, positive changes, treatment barriers, perceived knowledge gain, motivation, image change of setting). Assessment was carried out by semi-standardised interviews of the study therapists and a survey of the head of the setting.

4. Development and pilot testing of the group-therapeutic CANDIS version

In order to make an economic treatment offer available also for large addiction treatment centres with a large number of clients with cannabis use, CANDIS single therapy was enhanced to a group-therapeutic program version (CANDIS_G). Aim of the new format was to especially apply the therapeutic advantages of group processes (motivation, feedback, social support, model learning). Therefore mainly the didactic procedure of the therapist was adapted. Structure, content and working materials of each treatment unit broadly remained the same. Feasibility and effectivity of CANDIS_G was to be tested within the scope of a small pilot project.


The majority of study participants were males, average age was 26.3 years. Participants mainly had intensive cannabis use (approx. 21 use units per week), 88% fulfilled the lifetime diagnoses criteria (ICD-1) of cannabis dependence. According to the study results, participants benefitted from the intervention. Each second patient in the active therapy condition became abstinent; in the waiting control group each fourth patient. The performed urine screenings supported these results. Patients who did not become abstinent within the scope of treatment could, however, obtain a highly significant reduction of consumption days during the last 4 weeks. Therapy effects remained stable during catamnesis period.

After therapy conclusion, all patients were asked to give grades for the CANDIS therapy. This resulted in an average grade of 1.6. Study therapists evaluated the programme on an average of  „good“. The most important factors hampering the programme transfer were stated by the study therapists in the process evaluation.

1.) Manualised therapy is difficult due to lack of spare time and high work load for problematic clients (e. g. unstructured, comorbidity, poor motivation for change).

2.) Prejudices of colleagues against manualised therapy and

3.) Poor cooperation with other regional services. Central factors promoting the transfer were:

– Manualised procedure allows for clear structure, textual concept and documentation
support of treatment,
– Clarified cost takeover of the programme,
– Workshops for the mediation of contents and setup of competences and regular case reviews.


The CANDIS programme was well accepted by patients and therapists under routine conditions of the German outpatient addiction treatment net. It proofed to be effective for the treatment of problematic cannabis use.


Hoch, E. (2016). Behandlung cannabisbezogener Störungen. Habilitationsschrift. Eingereicht bei der Hohen Medizinischen Fakultät Mannheim der Ruprecht-Karls-Universität Heidelberg.

Hoch, E., Bühringer, G., Pixa, A., Dittmer, K., Henker, J., Seifert, A., Wittchen, H.U.. (2014) CANDIS treatment program for cannabis use disorders: Findings from a randomized multi-site translational trial. Drug and Alcohol Dependence 134 (2014) 185–193

Hoch, E., Zimmermann, P., Henker, J., Rohrbacher, H., Noack, R., Bühringer, G., Wittchen, H.-U. (2017). CANDIS Curriculum. A Marijuana Treatment Program for Youth and Adults. Hazelden: Betty Ford Foundation.

Neumann, M., Bühringer, G., Höfler, M., Wittchen, H.U., Hoch, E. (2018). Is cannabis use treatment also indicated for patients with low to moderate polysubstance use? European Addiction Research, 24(2):79-87.


The following 10 addiction treatment settings plus one reserve setting participated in the study – implementation of the targeted therapy for cannabis disorders “CANDIS” in the German outpatient addiction treatment net:

Adolescent and Drug Counselling Dresden

Wiener Straße 41
01219 Dresden
Tel.: 0351 / 42 77 30
Ansprechpartner: Vivien Götzke-Tonn

Psychosocial Counselling and Treatment Setting for drug-prone Persons and Addicts

Löbauer Str.48
02625 Bautzen
Tel.: 03591 / 32 61 140

LogIn Youth- and Addiction Counseling

Kaiser-Friedrich-Str. 82
10585 Berlin
Tel.: 030 / 21 57 833
Ansprechpartner: Fr. Grastorf, Fr. Nimir

Therapieladen e.V.

Potsdamer Straße 131
10783 Berlin
Tel.: 030 / 23 60 779-0

Caritas Special Outpatient Clinic for Young Addicts

Dachauer Str. 29
80335 München
Tel.: 089 / 54 58 32-0
Ansprechpartner: Sven Frisch

Release Stuttgart e. V. & Outpatient Clinic and Treatment Service Stuttgart Hospital (cooperation)

Villastr. 11
70190 Stuttgart
Tel.: 0711 / 60 17 37 30

Türlenstr. 22a
70191 Stuttgart
Tel.: 0711 / 253 29 305

Suchtambulanz der LWL-Klinik Münster

Friedrich-Wilhelm-Weber-Str. 30
48147 Münster
Tel.: 0251 / 591-02

Caritas Fachambulanz für Suchtprävention und Rehabilitation Osnabrück

Johannisstraße 91
49074 Osnabrück
Tel.: 0541 / 341-404
Ansprechpartner: Herr J. Kirchhoff, Claudia Westermann

Drobs Hannover

Odeonstraße 14
30159 Hannover
Katrin Alberts: Tel.: 0511 / 70 14 633
H. Wollnik: Tel.: 0511 / 70 14 624

Die Boje – Suchtberatung und -behandlung

Brauhausstieg 15-17
22041 Hamburg
Tel.: 040/ 444 091 sowie 040 / 73 14 949


Jugend- und Drogenberatung Braunschweig

Außenstelle “Clear”
Saarbrückener Str. 50
38116 Braunschweig
Fr. Scornavacche: Tel.: 0531 / 22 09 00
Fr. Herzmann: Tel.: 0531 / 480 79 90