Cause: Blood Type

... we have isolated that schizophrenia is largely linked to Blood Type O. Genetic predisposition to alcoholism runs in Blood Type A. There is continuous on-going research, but links are being identified.

You can see manifestations of this clumping in the emotions: depression in Blood Type O, for instance. Often they are not eating enough protein, and when they start eating more protein they begin to feel much better. Most notably, mental functioning improves, whether on or off medication.

Read the full article: Blood Types and Nutrition