ADD and ADHD kids are virtually always allergic. Expense is only one drawback. As a dramatic example, in one case, road dust from a dirt road near one patient's home caused deep depression.
Cures are permanent, whereas some allergens can change.
In fact, we recommend that at the same time the biofeedback training is done, a simple allergy search test can be done at home as well. This will often help, and in some cases, it will lower the number of sessions considerably. This simple test is outlined on Allergy Testing web page. You can translate any page on this website into any one of several languages by using the translate button at the bottom of each page. The translation will be literal, and will have some mistakes, but it should be readable for those who do not speak English.