Then his mother read my 1998 book, “Change Your Brain, Change Your Life,” which applies brain science to everyday life. She brought Sam to our clinic. After taking his history and doing a noninvasive brain scan, I diagnosed him with ADD, to be sure–but a kind of ADD largely ignored by doctors. Sam has what I call “overfocused ADD,” one of several variants of the disorder. Sam did need medication to get better, but he needed the right medication. As we balanced his brain, his behavior improved.

Unfortunately, ADD is generally treated as a single disorder. Our research, which has yet to win broad acceptance, suggests that there are six distinct types of ADD, each with its own treatment options. Used by themselves, standard treatments such as Ritalin can actually make four of these types worse.

Most doctors who treat ADD make the diagnosis based on symptoms. They rarely look at brain function, which–with three ADD children of my own–I came to regard as critical. While directing a large clinic in Fairfield, Calif., I began using an imaging technique called SPECT, which measures brain blood-flow and activity patterns. Over the past 11 years we’ve built a database of 10,000 brain images related to behavioral problems.

Right away we saw that the ADD brain is different. Typically, when people with ADD try to concentrate there is decreased activity (rather than the expected increase) in the part of the brain that helps with sustained attention, short-term memory and forethought. In theory, stimulants increase brain activity in this region. But in looking at our ADD patients, we found different brain patterns; those who departed from the norm were the ones for whom traditional ADD treatment did not work. Eventually, we classified these differences into six distinct types.

Type 1: Classic ADD–primary ADD symptoms (distractibility, disorganization) with hyperactivity, restlessness and impulsivity. It is usually recognized early and can best be treated with stimulant medications such as Adderall or Ritalin. My patients also benefit from higher-protein diets.

Type 2: Inattentive ADD–primary ADD symptoms with low energy and motivation. Type 2 is diagnosed later in life, if at all. It is more common in females. People with this condition are often labeled lazy or spacey. Like Type 1, it reponds well to stimulant medication and a higher-protein diet.

Type 3: Overfocused ADD–primary ADD symptoms with cognitive inflexibility and difficulty with shifting attention. Sufferers often display negative thoughts and behaviors. They worry, bear grudges and are argumentative. This type is often seen in families with addiction problems or obsessive-compulsive tendencies. By themselves, stimulants usually make this type worse; patients really focus on what bothers them. For this type of ADD, I prescribe an antidepressant (Effexor or a selective serotonin-reuptake inhibitor [SSRI] such as Prozac), combined with a stimulant and a higher-carbohydrate diet.

Type 4: Temporal-lobe ADD is marked by primary ADD symptoms with a short fuse, periods of anxiety, memory problems and difficulty reading. There may be a history of head injury, or a family history of learning or temper problems. Taken alone, stimulants usually make these people more irritable. In my experience, Type 4 is effectively treated with a combination of an anti-seizure drug like Neurontin, a stimulant and a higher-protein diet.

Type 5: Limbic ADD involves primary ADD symptoms, together with mild sadness, low energy, low self-esteem, irritability, social isolation and poor appetite and sleep patterns. Stimulants alone often exacerbate the moodiness and irritability. So I prescribe a stimulating antidepressant such as Wellbutrin, with aerobic exercise and a balanced diet.

Type 6: I call this “ring of fire” ADD. It features primary ADD symptoms with extreme moodiness, anger outbursts, inflexibility, fast thoughts and excessive talking. Patients tend to be sensitive to sounds and lights. I gave this variant its name because of the intense ring of overactivity that I saw in the brains of affected people. This type is usually made much worse by stimulants. My patients have done better on anticonvulsants such as Neurontin, combined with an SSRI or a new antipsychotic medication such as Risperdal or Zyprexa. Aerobic exercise also seems to help.

ADD, then, is a multifaceted illness that usually responds to well-targeted treatment. However, without a vast change in the way doctors look at ADD, millions will be left untreated or mistreated by the very people they depend on. I believe this?as a doctor, a researcher and a parent.