Multi-country Project on the Role of Diet, Food-related Behavior, and Obesity in the Prevention of Depression

Research has shown that nutrition may be an important way to promote mood and health, but so far researchers do not know which aspects of nutrition and behaviour are most important. The study is collaboration between the United Kingdom, Germany, Netherlands and Spain, funded by the European Commission. The trial compares different nutritional and lifestyle strategies that might promote mood and health in people who are overweight. For this purpose the design is a two-by-two factorial randomized controlled prevention trial with two intervention conditions: a multi-nutrient supplement and a food-related behavioural change (FBC) intervention. A total of four intervention groups are created: control condition (placebo, no FBC intervention), placebo with FBC intervention, multinutrient supplement with no FBC intervention, multi-nutrient supplement with FBC intervention.Recruitment: 1000 subjects will be recruited at four study sites in different EU countries (United Kingdom, Germany, Netherlands and Spain). Participants will be randomized with equal probability to the four intervention arms using a blind computerised randomization procedure.The multinutrient supplement and the placebo needs to taken every day during one year. The multinutrient supplement pill will contain omega 3 fatty acids, vitamin D, folic acid, selenium and calcium. FBC will consist of 21 behavioral activation sessions to adopt healthy diet behaviours that are known to explain the association between food intake and depression.

Follow-up assessment will be conducted by researchers unaware of the randomization status at 3, 6, and 12 months for primary and secondary outcomes. Data will first be analyzed according to the intention-to-treat principle, using (mixed model) analysis of covariance with primary and secondary endpoints, testing for the effects of the two nutritional strategies separately as well as combined (following the 2x2 factorial design of the trial). Per-protocol analyses and mediation analyses will be conducted to examine to what extent compliance and potential mediating mechanisms explain the impact on the primary and secondary endpoints. Data collection at the different sites will be conducted according to the strictest European code of ethics and conduct as well as codes for Good Clinical Practice, and local/national and international laws and regulations, including the Declaration of Helsinki. In a random subsample of trial participants (n=50 per intervention arm) blood samples will be collected at baseline, and after 3 and 12 months to measure blood levels of the nutrients provided with the multi-nutrient supplement.

Inclusion criteria

• Age 18- 75 years
• Body Mass Index 25-40
• PHQ-9 score ≥ 5

Exclusion criteria

• Current (in past 6 months) clinical Major Depressive Disorder Episode (according to psychiatric DSM-IV criteria as determined with The Mini-International Neuropsychiatric Interview 5.0 (M.I.N.I. 5.0)
• Current (in past 6 months) use of antidepressant drugs or psychological interventions.
• History of psychosis, bipolar disorder, substance dependence or other severe, psychiatric disorder that requires specialized clinical attention. No eating disorders. This will all be measured with a brief self-report questionnaire.
• History of bariatric surgery and no current severe, life-threatening disease (assessed using self-report), and no severe cognitive impairment limiting the conduct of the study, as assessed through research staff- evaluation of feasibility of conducting the screening instruments in an adequate manner.
• Currently adhering to supervised behavioural interventions that intervene with MoodFood interventions. If persons are on specific dietary supplements that are competing with the MoodFood intervention, than persons must be willing to stop what they were using before the start of this study
• Non pregnant or breast feeding