Nutritional counselling in adults promoting adherence to the Mediterranean diet as adjuvant in the treatment of major depressive disorder (INDEPT): a randomized open controlled trial study protocol

• Published in: BMC psychiatry 2023-04, Vol.23, p.1-11
• Main Authors: Sousa Santos, Nuno, Fialho, Mónica, Madeira, Teresa, dos Reis Clara, Cátia Andreia, Veiga, Sofia, Martins, Raquel, Barros, Neuza, Santos, Gabriela, Santos, Osvaldo, Almeida, Carolina, Ganança, Licínia, Campos, Rui C., Camolas, José, da Silva, Alda Pereira, Guarino, Maria Pedro, Heitor, Maria João
• Format: Article
• Language: English
• Subjects: Depression; Inflammation; Major depressive disorder; Mediterranean Diet; Randomized Controlled Trial
• ISSN: 1471-244X

Funding This study is funded by Portuguese national funds provided by Fundação para a Ciência e Tecnologia (FCT) UI/05704/2020, PTDC/SAU-NUT/3321/2020, and FCT202008719BD. MPG was funded by CEECINST/00051/2018. The study sponsor and funder of this trial are not directly involved in any of the following procedures: study design; collection, management, analysis, and interpretation of data; writing of the report; or the decision to submit the report for publication. The ultimate authority over any of these activities is the responsibility of the responsible investigator for the project (PhD Maria João Heitor). Background Major Depressive Disorder (MDD) is a leading cause of disability worldwide. Approximately one-third of patients with MDD do not respond to treatment, and often exhibit elevated inflammation biomarkers, which are associated with worse prognosis. Previous research has linked healthier dietary patterns, such as the Mediterranean Diet (MedDiet), with a lower risk of MDD and symptoms of depression, potentially due to their anti-inflammatory properties. The aim of this study is to evaluate the effectiveness of a nutritional counselling intervention promoting MedDiet to alleviate symptoms of depression in adults recently diagnosed with MDD and presenting with elevated inflammation biomarkers. Methods This study is a randomized controlled trial (RCT) that will recruit adults from outpatient clinics, between the ages of 18 and 70 years who have been diagnosed with MDD and are currently receiving treatment with the first prescribed antidepressant, and who exhibit elevated inflammation biomarkers (interleukin-6 and/or C-reactive protein). The control group will receive treatment-as-usual (TAU) only. The primary outcome of the study will be the change in symptoms of depression, as measured by the Beck Depression Inventory 2 (BDI-II), after 12 weeks of intervention. Data analysis will follow an intention-to-treat approach. Secondary outcomes will include changes in inflammation biomarkers, quality of life, adherence to the MedDiet, and cost-effectiveness of nutritional counselling. All outcomes will be assessed at baseline, after the 12-week intervention, and at 6- and 12-months post-baseline. Discussion This study will be the first RCT to evaluate the effect of a nutritional intervention with anti-inflammatory properties, as an adjuvant in the treatment of MDD, in individuals diagnosed with MDD and elevated inflammation biomarkers. The results of this s