Because ADD symptoms are so general and diagnosis so varied, there are a number of possible explanations for "bad" behavior. Before you label your child as ADD or ADHD, you should rule out any possible medical or phsycolgical problems. Some of these may include but are not limited to: low blood sugar, allergies and sensitivities, vision and/or hearing problems, and learning disabilities.
Here we will deal with low blood sugar and food sensitivities/allergies.

*Hypoglycemia
Symptoms may include but are not limited to: sleeplessness, tantrums, crying for no apparent reason, hyperactivity, uncontrollable bahavior, hostility, distractiblity, headaches, moodiness, problems with being still, craving sweets, shakiness/irritablity before meals, improved behavior after meals, and defiance.
How can it affect behavior? If there is not enough sugar in our blood stream, our brain releases a chemical called epinephrine. Epinephrine, more commomly known as adrenaline, can effect every part of our body and cause the symptoms listed above. Adults sometimes have trouble handling large amounts of adrenaline. We can hardly expect a child to be able to deal with it.
What causes hypoglycemia? It occurs when the bloodstream does not have enough sugar. One way this happens is by infrequent eating and another is by eating a lot of sugary foods (reactive hypoglcemia).
What can I do? Speak to your doctor first about how best to determine if your child has hypogycemia. If it is determined that the problem is hypogycemia, there are two possible solutions. First, make sure your child eats frequently. (Try to make it every every 2-4 hours). Second, for those with reactive hypogycemia, eliminate as much of the sugary foods as you can. This includes foods containing corn syrup and/or other sweeteners. Aspartame is one that should always be avioded.
Food Allergies & Sensitivities
Symptoms for this may include but are not limited to: bed and/or daytime wetting, hyperactivity, easily distracted, hard to control, learning difficulties, irritablity, and physical complaints such as vomiting, infections, skin rashes, headaches, sinus problems, constipation, diarrhea, and constant fatigue.
To determine if there is an allergy or sensitivity you can try several methods. I highly recamend an elimination diet. To do this, remove all foods that you suspect may cause problems for a period of at least 7 days and then then reintroduce them one at a time. Introduce only one food every couple of days for best posible results. Common food allergens include
peanuts, soy, dairy, shellfish, and eggs. Any food that is craved or eaten frequently should be included in your suspect foods list.
Please also read...
The Feingold Diet and My Family's Story.
This diet changed my life. Please do not skip this section.

Medications?
To medicate or not to medicate. That is a tough question. Medication may be the answer for your child (or yourself). However, I urge you to rule out natural solutions first. Listed here are some of the possible side effects for 2 of the more commonly used medications. Both are narcotic and have the potential for abuse. They have been sold as street drugs in some areas.
Ritalin: loss of appetite, irritability, insomnia, growth problems, tics, etc.
Rick could not sleep and was irritable while on this. It also affected his growth.
Adderall: loss of weight & appetite, dizzy sells, insomnia, tics, etc.
Rick lost weight and had no appetite..

This is a small selection of information from a paper called "Diet and Behavior: A Selection of Relavent Research Arcticles" published by The Feingold Association of the United States. Each selection is written word for word from this publication. (If you have not read the information on The Feingold Diet, please take the time to do that.) These studies were published by various organizations and publications. In each selection is the proper credit for the information.