My friend has been having nightmares for a year now and it's getting worse. she has headaches too. any ideas?

Yes: Almost certainly lousy diet, especially all sweeteners.

See a counselor or: And/or psychiatrist. Although it would be best to start with the pcp. Often stress is the cause of nightmares. Anxiety and depression may be an issue. Headaches can be a manifestation of depression. A thorough history should also be obtained by this persons primary physician to assess for other factors such a excessive alcohol consumption.