Olfactory training with patients suffering from depressive disorders
Organizational Data
- DRKS-ID:
- DRKS00016350
- Recruitment Status:
- Recruiting complete, study complete
- Date of registration in DRKS:
- 2018-12-19
- Last update in DRKS:
- 2021-01-12
- Registration type:
- Retrospective
Acronym/abbreviation of the study
OTDD
URL of the study
No Entry
Brief summary in lay language
We invited 102 patients suffering from depression to take part in a "smell training", smelling on four bottled odors daily for a time-period of four months to see if it helps reduce depressive symptoms and compared this effect to a depressive control Group that solved sudokus in the same time period.
Brief summary in scientific language
By means of a randomized controlled intervention study, we investigated whether olfactory training is a useful complementary strategy for depression treatment in a sample of 102 depressive out-patients.
Health condition or problem studied
- ICD10:
- F32 - Depressive episode
- ICD10:
- F33 - Recurrent depressive disorder
- ICD10:
- F43.2 - Adjustment disorders
- Healthy volunteers:
- No Entry
Interventions, Observational Groups
- Arm 1:
- Experimental group: Depressive Patients diagnosed with F32, F33 and F43.2 completed an olfactory Training over a time-period of 16 weeks. This daily short-time exposure comprised smelling on the four bottled odors rose, lime, eucalyptus and glove and rating intensity of the odors, mood and energy level in a "smell diary" once a week.
- Arm 2:
- Control group: Depressive Patients diagnosed with F32, F33 and F43.2 completed a "cognitive Training" over a time-period of 16 weeks. This comprised solving sudokus twice a day for five minutes and rating perceived difficulty of the task, as well as mood and energy level in a "Sudoku diary" once a week.
Endpoints
- Primary outcome:
- We aimed to investigate in a sample of clinically depressed patients whether Olfactory Training (OT) has a positive effect on depressive symptoms, compared to a placebo training, which we expected not to show any beneficial effect. In line with the previous research in this field, we furthermore hypothesized that OT improves olfactory function and, as a “side effect”, cognitive function. On average, the post-test appointment was arranged 16 weeks after pre-test. The participants had to fullfill the Training on a regular Basis at least for 12 weeks to be included in the statistical data analysis. Depressive symptoms were assessed using the Beck Depression Inventory (BDI-II; Beck et al., 1996; Hautzinger, Keller, & Kühner, 2006). Additionally, the 36-item Short Form Health Survey (SF-36) (Bullinger et al., 1995) was applied in the pre-test to measure health-related quality of life. Olfactory function in terms of odor threshold and identification ability was measured with a validated and reliable forced choice paradigm using the Sniffin’ Sticks testing kit (Burghart GmbH, for a detailed description see (Hummel, Sekinger, Wolf, Pauli, & Kobal, 1997)). In addition to the assessment of objective olfactory function, we also asked our participants about their individual importance of olfaction with a questionnaire (Croy, Buschhüter, Seo, Negoias, & Hummel, 2010). In order to control for a potential cognitive impact on olfactory function and affective disorders, two cognitive tests were performed with the participants: The revised d2 attention and concentration test (Brickenkamp & Zillmer, 1998), and the Regensburger verbal fluency test (RWT; Aschenbrenner, Tucha, & Lange, 2000). In order to control for potential confounders accompanying diseases, we included a medical history questionnaire. The recruitment ran continuosly between November 2015 and September 2017, so that the post-test data of the last participant was collected in September 2017.
- Secondary outcome:
- In the same sample of depressive out-patients, we examined the influence of severity, course and duration of depression on olfactory function. We expected severity, course and duration of depression affecting olfactory function in terms of a reduction in olfactory function (odor identification and odor threshold). We used the same methods as described above to examine this research question. Furthermore, we divided the sample into three sub-groups, taking the BDI score, the diagnoses (F32 vs. F33) and duration of depression into account.
Study Design
- Purpose:
- Treatment
- Allocation:
- Randomized controlled study
- Control:
-
- Placebo
- Phase:
- N/A
- Study type:
- Interventional
- Mechanism of allocation concealment:
- No Entry
- Blinding:
- No
- Assignment:
- Parallel
- Sequence generation:
- No Entry
- Who is blinded:
- No Entry
Recruitment
- Recruitment Status:
- Recruiting complete, study complete
- Reason if recruiting stopped or withdrawn:
- No Entry
Recruitment Locations
- Recruitment countries:
-
- Germany
- Number of study centers:
- Monocenter study
- Recruitment location(s):
-
- University medical center Klinik für Psychotherapie und Psychosomatik Dresden
Recruitment period and number of participants
- Planned study start date:
- No Entry
- Actual study start date:
- 2015-11-05
- Planned study completion date:
- No Entry
- Actual Study Completion Date:
- 2017-09-02
- Target Sample Size:
- 121
- Final Sample Size:
- 102
Inclusion Criteria
- Sex:
- All
- Minimum Age:
- 18 Years
- Maximum Age:
- 99 Years
- Additional Inclusion Criteria:
- Symptoms of an at least mild depression (BDI-score >13 and <20) served as inclusion criterion. Sufficient German skills and an age of >17 yrs were also mandatory.
Exclusion Criteria
Exclusion criteria were diagnosed anosmia, chronic nasal diseases, neurodegenerative diseases, and metabolic diseases, as well as being currently affected with acute respiratory diseases like colds and influenza, although frequent respiratory diseases in their medical history were not an exclusion criterion. Furthermore, current psychological treatment, antidepressant medication or the admission into psychotherapeutic treatment facilities during the course of training was not an exclusion criterion due to ethical reasons, but was taken into account for in the statistical data Analysis.
Addresses
Primary Sponsor
- Address:
- Klinik für Psychotherapie und Psychosomatik Universitätsklinikum Carl Gustav CarusJun.-Prof. Ilona CroyFetscherstr. 7401307 DresdenGermany
- Telephone:
- 0049-351-458-3502
- Fax:
- 0049-351-458-5713
- Contact per E-Mail:
- Contact per E-Mail
- URL:
- http://www.uniklinikum-dresden.de
- Investigator Sponsored/Initiated Trial (IST/IIT):
- Yes
Contact for Scientific Queries
- Address:
- Klinik für Psychotherapie und PsychosomatikUniversitätsklinikum Carl Gustav Carus DresdenDipl.-Psych. Luise PabelFetscherstr. 7401307 DresdenGermany
- Telephone:
- 0049-351-458-17079
- Fax:
- No Entry
- Contact per E-Mail:
- Contact per E-Mail
- URL:
- https://www.uniklinikum-dresden.de
Contact for Public Queries
- Address:
- Klinik für Psychotherapie und PsychosomatikUniversitätsklinikum Carl Gustav CarusDipl.-Psych. Luise PabelFetscherstr. 7401307 DresdenGermany
- Telephone:
- 0049-351-458-17079
- Fax:
- No Entry
- Contact per E-Mail:
- Contact per E-Mail
- URL:
- http://www.uniklinikum-dresden.de
Principal Investigator
- Address:
- Klinik für Psychotherapie und PsychosomatikUniversitätsklinikum Carl Gustav Carus DresdenDipl.-Psych. Luise PabelFetscherstr. 7401307 DresdenGermany
- Telephone:
- 0049-351-458-17079
- Fax:
- No Entry
- Contact per E-Mail:
- Contact per E-Mail
- URL:
- https://www.uniklinikum-dresden.de
Sources of Monetary or Material Support
Private sponsorship (foundations, study societies, etc.)
- Address:
- Medizinische FakultätFetscherstr. 7401307 DresdenGermany
- Telephone:
- 0049-351 458-3306
- Fax:
- No Entry
- Contact per E-Mail:
- Contact per E-Mail
- URL:
- https://tu-dresden.de/med/mf/forschung/services-fuer-forschende/foerderprogramme-fuer-nachwuchswissenschaftler/meddrive
Ethics Committee
Address Ethics Committee
- Address:
- Ethikkommission an der TU DresdenFetscherstr. 7401307 DresdenGermany
- Telephone:
- +49-351-4582992
- Fax:
- +49-351-4584369
- Contact per E-Mail:
- Contact per E-Mail
- URL:
- No Entry
Vote of leading Ethics Committee
- Vote of leading Ethics Committee
- Date of ethics committee application:
- 2015-01-19
- Ethics committee number:
- EK48022015
- Vote of the Ethics Committee:
- Approved
- Date of the vote:
- 2015-02-03
Further identification numbers
- Other primary registry ID:
- No Entry
- EudraCT Number:
- No Entry
IPD - Individual Participant Data
- Do you plan to make participant-related data (IPD) available to other researchers in an anonymized form?:
- No Entry
- IPD Sharing Plan:
- No Entry
Study protocol and other study documents
- Study protocols:
- No Entry
- Study abstract:
- No Entry
- Other study documents:
- No Entry
- Background literature:
- No Entry
- Related DRKS studies:
- No Entry
Publication of study results
- Planned publication:
- No Entry
- Publikationen/Studienergebnisse:
- No Entry
- Date of first publication of study results:
- No Entry
- DRKS entry published for the first time with results:
- No Entry
Basic reporting
- Basic Reporting / Results tables:
- No Entry
- Brief summary of results:
- No Entry