Omega 3 fatty acids are essential for the healthy functioning of the nervous system. These cannot be produced by the human body. They have to be ingested through various foods. Alcohol is known to trigger depression, even though it is actually used as means of escape from emotional problems. Caffeinated beverages and sugary foods provide a temporary lift, but once the effects subside, feelings of depression can resurge. According to diet therapy, a balanced diet consisting of all the essential vitamins and other nutrients is necessary to prevent depression. These nutrients are also important for the general functions of the human body. Vitamin B1 is required for the production of energy and for functioning of the nerve cells. Vitamin B6 is necessary for hormonal regulation. Vitamin C improves the functioning of the immune system.

Inadequacies in the diet can contribute to feelings of depression. Studies have shown that depressed individuals have higher levels of calcium in the cerebrospinal fluid, while those that are suicidally depressed tend to have lower levels of magnesium. Inadequate intake of polyunsaturated fatty acids, folate, vitamin B-12 and antioxidant vitamins are linked with depression. The B group vitamins are vital to mental health. The human body is unable to store these vitamins and as such they must be obtained from the daily diet. Refined sugars, alcohol, caffeine and nicotine destroy the B complex vitamins, thereby resulting in depressive feelings. Many other vitamin deficiencies are also known to result in symptoms of depression. Once these deficiencies are corrected, the depressive symptoms are often alleviated. Beneficial foods include fresh fruits, green vegetables, whole cereals, seed sprouts and soy protein. Processed foods and those products that contain artificial colors must be avoided.