In Ayurveda (comes from hindu sages, invented yoga etc) they say that some forms of depression come from the gut brain axis. THere are 3 types of body type and eating the wrong foods for each body type can make your mind inbalanced. Whilst in comparision western nutrionists/dieticians say have a balanced diet, Ayurveda says eat foods depending on your body type its not as simple as calories, protein, carbs. It depends on the food itself.