Genes and Meds

Someday we will be able to tell which patients will do well by which medications by looking at their genes. This will happen for ADHD patients as well as for many other kind of patients. When that information is available, instead of the current system of, “first we’ll try this, and if it doesn’t work then we will try that,” we will have a scientific and highly accurate plan. We will link up our illnesses with medications that we can count on to be helpful.

Sound like science fiction? It may — but we are closing in on being able to do it. Some Brazilian researchers have recently studied treating children and adolescents with ADHD with methylphenidate (Ritalin). They found that youngsters with ADHD who had a specific genetic alteration (the so-called ADRA2A-1291 C>G polymorphism) responded better with treatment using methylphenidate (Ritalin). (The full reference to this research is: Polanczyk G, Zeni C, Genro JP , et al: Association of the adrenergic alpha 2A receptor gene with methylphenidate improvement of inattentive symptoms in ADHD. Arch Gen Psychiatry 64:218-224, 2007.)

We know that this gene is important in determining how well the brain uses norepinephrine, or adrenaline. When there is an abnormality there, it may contribute to ADHD symptoms. The ADHD symptoms of patients who had this abnormality steadily improved with increasing doses of methylphenidate.

This clinical study just used one medication. Certainly other research needs to be done to see if other medications work as well if not better for patients with this genetic makeup.

What counts is the principle of the thing: linking specific genetic findings with specific effective medications. There will be increasing numbers of such studies as clinical researchers work to make treatment for ADHD and other disorders more specific and more effective.