Plain English Summary
Background and study aims
Mood disorders in children and adolescents are a serious problem worldwide, and are becoming more common in younger children. In recent years, research has been focused on the adjuvant therapy of depression (extra treatment to enhance the effects of the main treatment) with the aim of reducing the consumption of antidepressants, to prolong remission (disease-free periods) and improve the outlook for these patients. The use of Omega-3 fatty acids as an adjuvant therapy have been shown to be promising, with beneficial effects in the prevention and treatment of depression. The aim of this study is to assess the effectiveness of omega-3 fatty acids rich fish oil in the treatment of depression symptoms in children and adolescents treated for depression as well as to find out what effects this has on the body by looking at biochemical markers (substances).
Who can participate?
Children and adolescents aged 8–18 years suffering from depression who are registered at the Department of Child psychiatry of Comenius University and Child University Hospital in Bratislava.
What does the study involve?
Patients are randomly allocated to one of two groups. Those in the first group take 20 mL of omega-3 fish oil emulsion every day for 12 weeks in addition to their usual treatment, followed by 4 weeks of not taking the oil. Those in the second group take 20 mL of omega-6 sunflower oil emulsion every day for 12 weeks in addition to their usual treatment, followed by 4 weeks of not taking the oil. At the start of the study, every two weeks during the 12 week treatment period, and then at 16 weeks, participant have their symptoms of depression assessed and have blood and saliva samples taken to measure for chemical indicators of the effects the supplements are having on the body.
What are the possible benefits and risks of participating?
Participants who receive the omega 3 oil may benefit from a reduction of their depressive symptoms. There are no known risks involved with participating.
Where is the study run from?
1. Comenius University (Slovakia)
2. Comenius University and Child University Hospital (Slovakia)
Who is funding the study?
Slovak Research and Development Agency (Slovakia)
When is the study starting and how long is it expected to run for?
March 2013 to June 2020
Who is the main contact?
Professor Zdenka Durackova
Prof Zdeňka Ďuračková
Institute of Medical Chemistry
Biochemistry and Clinical Biochemistry
Faculty of Medicine
+421 1 59357 564
Molecular bases of depressive disorders in children and adolescents, effect of omega-3 fatty acids, inflammation and oxidative stress
The aim of the current study is to compare the efficacy of 12 weeks administration of omega-3 fatty acids present in fish oil emulsion with a control oil emulsion (omega-6 fatty acids rich sunflower oil emulsion) alongside standard antidepressant treatment on depressive symptoms in children and adolescents (8 to 18 years old).
The study will investigate:
1. Clinical parameters: CDI score
2. Biochemical parameters: Lipid profile, fatty acid composition in serum LDL- and HDL-subfractions of lipoproteins, markers of oxidative stress and inflammation in blood, steroidal hormones in saliva
3. Biophysical parameters: Fluidity of erythrocyte membranes
4. The length of telomeres in the buccal cells
Ethical Committee of the Child University Hospital and the Faculty of Medicine, Comenius University Bratislava, Slovakia, 20/03/2013
Single-centre randomized double-blind comparator controlled interventional study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet in Slovakian
Depressive disorder (F32) or mixed anxiety and depressive disorder (F41.2)
Patients are allocated in a 1:1 ratio to the two arms (Om3 and Om6) according to a computer-generated random sequence using block randomisation with a block-size of four. The randomisation was performed by the independent statistician. Patients are enrolled and assigned sequentially to adjuvant interventions by the physician. The allocation sequence is not available to any member of the research team until the databases had been completed and locked.
Intervention group: Participants receive 20ml of an omega-3 FA rich fish oil emulsion (Om3), which provides 2400 mg of total omega-3 FA; 1000 mg EPA and 750 mg DHA, EPA:DHA ratio = 1.33:1, for 12 weeks in addition to their standard antidepressant therapy, followed by a 4 week wash out period.
Control group: Participants receive an identically looking comparator omega-6 sunflower oil emulsion containing min 2467 mg of omega-6 linoleic acid provided by Cultech Ltd, Port Talbot (UK) for 12 weeks in addition to their standard antidepressant therapy, followed by a 4 week wash out period.
Clinical examinations take place at the beginning of the project (week 0), and every 2 weeks for 3 months (weeks 2, 4, 6, 8, 10, 12) and after following 4 week wash-out period, at week 16. Ratings aree made using the self rated scale Children's Depression Inventory (CDI). Biological samples (blood, urine, saliva) are taken at the week 0, 6, 12 and 16.
Primary outcome measures
Clinical symptoms of depression are determined using Children's Depression Inventory score (CDI) at baseline, 2, 4, 6, 8, 10, 12 and 16 weeks.
Secondary outcome measures
1. Basic biochemical marker levels (glucose, uric acid, lipid profile (total cholesterol, LDL-CH, HDL-CH, TAG), creatinine, CRP, liver enzymes ALT, AST) are measured by testing blood samples taken at baseline, at the week 6 and 12 of intervention and after wash-out period, at the week 16
2. Markers of oxidative stress (antioxidant enzymes SOD, GPx, CAT in Er, PON1 in serum, markers of lipid damage - lipoperoxides, 8-IsoP, protein damage - AOPP, serum protein carbonyls, nitrotyrosine, DNA damage in lymphocytes by comet assay, total antioxidant status-TEAC) are measured by testing blood samples taken at baseline, at the week 6 and 12 of intervention and after wash-out period, at the week 16
3. Markers of inflammation (CRP, calprotectin, cytokines and eicosanoids, thromboxanes) are measured by testing blood samples taken at baseline, at the week 6 and 12 of intervention and after wash-out period, at the week 16
4. Hormones in saliva (cortisol, aldosteron) are measured by testing saliva samples taken at baseline, at the week 6 and 12 of intervention and after wash-out period, at the week 16
5. Erythrocyte (Er) membrane fluidity is measured by spectrofuorimeter at baseline, at the week 6 and 12 of intervention and after wash-out period, at the week 16
6. Composition and content of serum fatty acids (FA) are measured by gas chromatography at baseline, at the week 6, 12 of intervention and after wash-out period, at the week 16
8. Length of DNA telomers in buccal cells is measured by qPCR at baseline and at 12 week intervention
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Children and adolescents who met diagnostic criteria for depressive disorder or mixed anxiety and depressive disorder according to ICD 10
2. No signs of chronic somatic disease
3. Normal eating habits
4. Parents/guardian are willing to provide a signed informed consent
5. Children and adolescents are willing to provide the blood, urine and saliva samples
Target number of participants
60 = 30 in omega-3 group and 30 in omega-6 group
Participant exclusion criteria
1. Chronic somatic diseases (endocrine, metabolic, autoimmune)
2. Dietary restrictions (vegetarians, lactose intolerance, celiac disease)
3. Psychotic disorders
4. Eating disorders
5. Addiction to psychoactive compounds
6. Personality disorders
7. Organic mental disorders
8. Pervasive developmental disorders
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Institute of Medical Chemistry, Biochemistry and Clinical Biochemistry Faculty of Medicine Limbova 1
Trial participating centre
Comenius University and Child University Hospital
Department of Child and Adolescent Psychiatry Limbová 1
Slovak Research and Development Agency (Agentúra na Podporu Výskumu a Vývoja)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journals of papers discussing:
1. Clinical symptoms – results of pilot study - 2017
2. Markers of oxidative stress – pilot results -2017
3. Markers of inflammation – pilot results 2018
4. Fluidity of membranes and fatty acid composition - 2019
5. Telomere length – 2019
6. Mutual relation between clinical symptoms and markers of oxidative stress and inflammation - 2020
IPD Sharing plan:
The datasets generated during and/or analysed during the current study will be available upon request from firstname.lastname@example.org and email@example.com
Intention to publish date
Participant level data
Available on request
Results - basic reporting