Recently my freind was diagnosed with parasites (hookworm and cryptospordium.) She clenched and grinded her teeth at night and also chewed her nails.
This research paper below has only two main symptoms listed in the worm infection study, and they were onychophagia(nail biting) and wheezing(asthma.)Note how it said that nail biting was quite prevalent among those infected. The study shows infection rates of other countries, but we should never assume that just because we live in America we are somehow exempt from them. (case in point, my freind was infected with TWO). Although we might have less because of our sanitation, we still get parasites. They are rarely ever considered by modern medical doctors, although many years ago doctors used to deworm all thier patients every 6 months.(Maybe that is how the 6 month checkup came to be?) My freind had to go to a natural doctor to get the lab work ordered from medimetrix.
http://www.tparazitolderg.org/text.php3?id=295
http://www.nutritional-solutions.com/asp/parasites.asp
I have a 12 DD who bit her nails. I went online last week and ordered Humaworm for her. She has other health issues too, so I am going to see if it helps her.
Nervous / anxiety disorders can be helped by minerals and vitamins. Magnesium deficiency causes high adrenaline. Magnesium supplementation can help with anxiety, compulsive disorders, depression, etc. Vit B also supports the nervous system. I give my kids liquid b complex (sublingual) under the tounge daily.
Serotonin is responsible for mood and disruptions in serotonin level or delivery (bacteria hijacks the receptors) can initiate mood and anxiety problems. 80% of your seratotonin resides in your gut, the same place where bacteria, worms, and other parasites reside as well. Magnesium and b6 help make serotonin. Interesting huh?
Another thing that can cause phychological/stress and anxiety symptoms is Mercury and heavy metal poisoning. look up symptoms online.
You should use this information as a springboard for your own research and consult your doctor for proper diagnosis and treatment.