Condition category
Mental and Behavioural Disorders
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Agoraphobia is a fear of being in situations where escape might be difficult or that help wouldn't be available if things go wrong. It usually develops as a complication of panic disorder, an anxiety disorder involving panic attacks and moments of intense fear. Agoraphobia can be treated with cognitive behavioural therapy (CBT), a talking therapy that can help patients manage their problems by changing the way they think and behave. CBT uses a type of therapy called exposure therapy, which involves being gradually exposed to the feared situation and using relaxation techniques and breathing exercises to help reduce anxiety. The aim of this study is to find out whether exposure therapy can be improved with the use of the drug D-cycloserine.

Who can participate?
Patients age 18-75 with panic disorder and agoraphobia

What does the study involve?
All participants undergo CBT consisting of eight group sessions within 1 month plus three individual exposure therapy sessions. One hour before the start of each exposure session, participants are randomly allocated to receive either D-cycloserine or a placebo (dummy drug). Panic and agoraphobia symptoms are measured at the start of the study, at the end of therapy (1 month after the start of the therapy), and at 2 and 6 months after the start of the therapy.

What are the possible benefits and risks of participating?
Not provided at time of registration

Where is the study run from?
Charite - Universitatsmedizin Berlin (Germany)

When is the study starting and how long is it expected to run for?
October 2007 to April 2009

Who is funding the study?
Federal Ministry for Education and Research (Germany)

Who is the main contact?
Dr Andreas Strohle

Trial website

Contact information



Primary contact

Dr Andreas Strohle


Contact details

Department of Psychiatry and Psychotherapy
Campus Charite Mitte
Charite - Universitatsmedizin Berlin
Chariteplatz 1
+49 (0)30 450 517 034

Additional identifiers

EudraCT number

2006-004860-29 number

Protocol/serial number


Study information

Scientific title

D-cycloserine-supported exposure in patients with panic disorder



Study hypothesis

Administration of D-cycloserine supports the therapeutic effect of exposure therapy in patients with panic disorder.

Ethics approval

Local Ethics Committee (Ausschuss 4 der Ethikkommission des Landes Berlin), 03/01/2007, ref: EK 5 618/06

Study design

Double-blind randomised placebo-controlled study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Panic disorder with agoraphobia


All patients will undergo cognitive behavioural therapy consisting of eight group sessions (group size: 4-8) within one month plus three individual exposure therapy sessions in a standardised procedure. One hour before start of each exposure session, half of the patients will receive 50 mg of D-cycloserine orally, and half of the patients will receive a placebo.

Intervention type



Not Applicable

Drug names


Primary outcome measures

Panic and Agoraphobia Scale, measured at baseline, at the end of therapy (one month after start of the therapy), 2 months after start of therapy, 6 months after start of therapy.

Secondary outcome measures

1. Mobility Inventory for Agoraphobia
2. Beck Depression Inventory
3. Beck Anxiety Inventory
3. Hamilton Rating Scale for Depression
4. Hamilton Rating Scale for Anxiety
5. Clinical Global Impression

Outcomes will be measured at baseline, at the end of therapy (one month after start of the therapy), 2 months after start of therapy, 6 months after start of therapy.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Subject familiarised with experimental procedure and had given written informed consent according to AMG §40(1)3b
2. Diagnosis of panic disorder with agoraphobia, at least "moderately ill"
3. Age: 18-75 years
4. Sufficiently able to communicate with investigator, answer questions and fill in questionnaires
5. If pre-menopausal female: negative pregnancy test and safe contraception during study period
6. Reachability of patient for treatment and follow-up
7. Compliance of patient

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Known overreaction to D-cycloserine
2. Hospitalisation in a mental institution according to AMG §40(1)4
3. Other psychiatric illnesses like schizophrenia, substance abuse or dementia
4. Acute suicidal tendency
5. Epilepsy or other illness of the central nervous system (CNS) (e.g. brain tumour, encephalitis)
6. Severe medical illness like severe hypertension, severe cardiac insufficiency, condition after acute myocardial infarction, cardiac arrhythmia of severity index IV or V according to Lown grade, severe dysfunction of liver or kidney, diabetes mellitus requiring insulin treatment, disturbances of haematopoiesis
7. Pregnancy or breastfeeding
8. Changes of psychopharmacological treatment within the last eight weaks or discontinuation of psychopharmacological treatment within less than four weeks before beginning of the study
9. Recent interference with diurnal cycle

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Charite - Universitatsmedizin Berlin

Sponsor information


Charite - University Medicine Berlin (Charite - Universitatsmedizin Berlin) (Germany)

Sponsor details

c/o Privat-Dozent Dr Andreas Strohle
Department of Psychiatry and Psychotherapy
Campus Charite Mitte
Chariteplatz 1
+49 (0)30 450 517 034

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Bundesministerium für Bildung und Forschung (ref: 01GV0612)

Alternative name(s)

Federal Ministry of Education and Research, BMBF

Funding Body Type

government organisation

Funding Body Subtype




Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2011 results in:

Publication citations

  1. Results

    Siegmund A, Golfels F, Finck C, Halisch A, Räth D, Plag J, Ströhle A, D-cycloserine does not improve but might slightly speed up the outcome of in-vivo exposure therapy in patients with severe agoraphobia and panic disorder in a randomized double blind clinical trial., J Psychiatr Res, 2011, 45, 8, 1042-1047, doi: 10.1016/j.jpsychires.2011.01.020.

Additional files

Editorial Notes

17/03/2017: Plain English summary added.