Developing new drugs is a lengthy process, but the discovery a new drug to treat ADHD actually began almost 80 years ago. That's when scientists at Yale began studying the prefrontal cortex, the region of the brain that is crucial to controlling our attention, actions and emotions.
More recently, Amy Arnsten, PhD, became fascinated by the prefrontal cortex when she realized that malfunctions in this brain region were the cause of many forms of mental illness, a field that had long interested her. Arnsten knew from work by other Yale researchers that the blood pressure drug clonidine helped patients with Tourette's syndrome, but it's a powerful sedative – too powerful for children. So she and her colleagues studied guanfacine, another high blood pressure medicine, to find out how it might affect the prefrontal cortex. They found that guanfacine helped neurons in the prefrontal cortex to communicate better by inhibiting certain chemical messages. Because it's more selective than clonidine – guanfacine prefers a single receptor site that's important for prefrontal cortex function – it has fewer side effects.
Doctors already knew that guanfacine was safe, but they didn't know if it would alleviate the symptoms of ADHD, one of the most common childhood disorders. To find out, Dr. Robert Hunt, then at Yale, tested it in a few adults. When it seemed safe and effective, he tried it in some of his pediatric patients with ADHD, where it also showed promise. This was good news because the few medications used to treat ADHD don't always work well and sometimes cause side effects. Because children metabolize guanfacine very quickly, an extended release version known as Intuniv was developed and tested in larger trials involving children. Today, it is helping ADHD patients to be less distracted and have better self control. Without the participation of young patients and their families, this promising new treatment would not have been possible.