Dietary Causes of Depression by Mona Jauhar (Functional Medicine, Dietician Nutritionist), she explains the correlation between food and depression through a case study example of one of her patients.

A 46-year-old female had been suffering from depression for 20 years. As she had been on antidepressants for such a long period, the effects of the medication had reduced upon her and her condition was growing progressively worse. She had stopped going out, and because of her Gastrointestinal (GI) problems, she was having antacids. Additionally, she started to develop intolerances towards foods which was a new symptom.

Mona Jauhar then examined her history and conducted some diagnostic tests on her. The results revealed that the patient had casomorphin and diamorphine in her urine which are the causes of gluten and casein not being digested properly. Through this Mona derived that her patient’s body is reacting to gluten and casein in her diet. Additionally, owing to her chronic use of antacids for GI issues, the patient was also deficient in vitamin  B12. Finally, because depression prevented her from going out she was not getting enough sunlight and so, was deficient in Vitamin D.

So, for this patient, Mona Jauhar recommended removing gluten and casein which is dairy out of her diet and supplemented her with Vitamin D and B12. With this dietary change, the patient’s symptoms started progressively resolving.