Nutritional interventions are scarcely used in the prevention and treatment of mental disorders.<br/> AIM: To summarize scientific evidence on the relation between nutrition and mental health, across the life span.<br/> METHOD: An overview of the literature based on recent knowledge syntheses, meta-analyses and original studies.<br/> RESULTS: Healthy dietary patterns are associated with a lower risk for depressive symptoms among adults and potentially also among children and adolescents. Dietary interventions can be effective in reducing depressive symptoms among high-risk groups and can have a beneficial effect in the treatment of depression. Meta-analyses of randomised studies have shown that omega-3 fatty acid supplements can be of added value in the treatment of adhd in children and of depression in adults.<br/> CONCLUSION: Promotion of healthy dietary patterns in line with National guidelines for healthy diets is important in the entire spectrum from good mental health to a chronic disorder. More attention for improving healthy dietary patterns among patients with mental disorders can lead to important health gains.