Your brain needs fish.

In his book, The Omega-3 Connection, Harvard psychiatrist Andrew Stoll says Americans get little omega-3 fatty acid found in fish. Lack of omega-3 is linked to depression, bipolar disorder, postpartum depression, and suicidal tendencies.

Dr. Joseph Hibbeln, the National Institutes of Health psychiatrist who studied the subject, says heart disease and depression often occur at the same time, and now doctors may know why.

One bipolar patient studied became so delusional that he landed in a psychiatric ward. Stoll prescribed a quarter pound of salmon daily as part of the treatment and the patient recovered.