DEAR DR. DONOHUE: Our great-grandson, who is 4½ years old, has been diagnosed with ADHD (attention deficit hyperactivity disorder).

We are in our 80s and cannot recall your ever mentioning it. We have been told that he inherited it from his father. His doctors are considering medicine for him. What does the future hold? – E. and B.L.

ANSWER: Let’s get the genetic part out of the way. About 25 percent of children with ADHD have a parent (mother or father) who has or had it.

More boys than girls have it. Maybe that’s why your source indicted the father, but it could be the mother.

Or, as is the case 75 percent of the time, neither parent has or had it.

ADHD is a common problem, with anywhere from 3 percent to 10 percent of children having it. Affected children are in perpetual motion. They find it difficult to focus on a task for any length of time. They’re impulsive, blurting out information when they’re not asked for it and jumping out of their seats to do things that should not be done.

The reason ADHD is so hard on a child is because it prevents the child from learning to his or her full capacity, and it disrupts a classroom.

There are a number of ways to control ADHD. Parents learning how to administer rational, calm discipline and how to overlook some of the child’s behavior can bring about changes in the way the child reacts.

Teachers can do the same. Sometimes medicines are needed. It’s believed that ADHD results from a botched-up release of two brain chemicals – dopamine and norepinephrine.

Ritalin can stimulate the brain to release those chemical messengers to help the child gain control.

Ritalin is only one example of an ADHD medicine.

The future looks bright for your great-grandchild. Symptoms often improve with time, although ADHD can persist into adulthood in some people.

Dealing with it now will make things better for the child as he grows older.

DEAR DR. DONOHUE: I am 87 and was told by an eye doctor that I have the slow type of macular degeneration. I can still drive and read.

I met a lady who told me she has had eye treatments with Visudyne and that they have helped her. I wonder if it’s best for me to take these treatments now. – J.G.

ANSWER: Many people your age have the beginnings of dry macular degeneration (the slow kind), and most of them will live their life without losing their sight.

Visudyne is treatment for wet macular degeneration, the kind that happens only to 10 percent of those with this illness. “Wet” means that new but fragile vessels sprout on the retina and macula, and leak fluid, which interferes with sight. Wet macular degeneration can progress rapidly.

Visudyne is a drug injected into a vein. It then concentrates in the newly sprouted, fragile eye blood vessels. The doctor turns a laser on those vessels, and they dry up. This treatment is not meant for you.

DEAR DR. DONOHUE: In 2003 I was diagnosed with genital herpes. Can I still have kids? Before I got the infection, I had a little baby boy. I know this disease is not curable, but I still want more children. Is that possible? – G.

ANSWER: Certainly it’s possible for you to have more, healthy children. Genital herpes rarely produces infertility.

The herpes virus cannot be eliminated from the body, but it can be controlled.

DEAR DR. DONOHUE: I wish to contribute to your article on peptic ulcers. In my opinion, a recently surfaced culprit – Bacterium computerensis – has a major role in causing them. It causes frequent pangs of stomach tightening, and it affects the nervous system. The only cure is eliminating it from one’s life. – L.K.

ANSWER: For readers who don’t catch L.K.’s meaning, he’s referring to computers. They often give me the symptoms he so graphically describes.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com