Celebrity designer Ty Pennington is known for inspiring people with remodeled dream homes and providing tips for functional, stylish decor.

He is also one of millions of Americans who struggle with attention deficit hyperactivity disorder (ADHD). Other stars like game show host Howie Mandel and Olympic swimmer Michael Phelps have also wrestled with the condition throughout their lives.

But for every person at the top of their game who successfully manages their ADHD, there are countless others who aren't able to. In fact, some with the condition may  find themselves at the bottom of society — in prison.

The same mental process evident in people with ADHD may also be associated with a tendency to criminal behavior, some experts say. While the link between the two is not well understood, some researchers are calling for more attention to this problem. Otherwise, there may be high costs to society, they say.

"If ADHD is left untreated, there is a serious risk that long-term problems will maintain substance use, consolidate antisocial attitudes and lifestyles and reduce the potential for rehabilitation," wrote researchers Susan Young and Emily Goodwin in an editorial last month in the journal Expert Reviews of Neurotherapeutics.

"Given that ADHD is a treatable condition with interventions available ... the enormity of this problem and its associated costs are too great to bear," the researchers said.

ADHD in prisons

ADHD is characterized by impulsive behavior, hyperactivity and inattention, making it difficult to function at home, school or other settings. In the United States, about 5.4 million children ages 4 to 17 were diagnosed with ADHD, and about 66 percent of those children were receiving treatment, as of 2007, according to a recent report by the Centers for Disease Control and Prevention.

Treatments for the condition include behavioral counseling, parent and/or school training and medications like the stimulant drugs Ritalin, Adderall and Vyvanse.

Boys suffer from the condition at higher rate than girls — 13.2 percent of boys have it, compared with 5.6 percent of girls, according to the CDC.

Recent studies of adult prisoners have shown that not only is ADHD more prevalent among those in prisons than in the general population, but also that within prisons, it's those with ADHD who seem to cause the most trouble, Goodwin and Young said.

Offenders with ADHD commit more violent acts and have higher levels of substance abuse than other prisoners, according to a study published in June in the Journal of Psychopharmacology. The study also found that having ADHD symptoms were the strongest predictor, followed by alcohol dependence, for violent behavior among the prisoners.

And the trouble may start early. Children with ADHD symptoms have a greater likelihood of committing criminal acts than other children, according to a 2009 study in the Journal of Mental Health Policy and Economics led by Jason Fletcher, an assistant professor of public health at the Yale University School of Public Health.

What makes some people with ADHD more prone to crime

There is no certainty that an adult with ADHD will engage in criminal acts, Fletcher said.

"Many people with ADHD do not commit crimes, so it is not deterministic," he  said.

However, ADHD does seem to be a risk factor for committing violent acts, Fletcher said.  In addition, for some adults with the condition, environmental triggers such as poverty could lead to similar criminal conduct among family members.

"Risky behaviors, including criminal behaviors, do seem to be associated within [families of people with ADHD]," Fletcher told MyHealthNewsDaily. "But the cause is unclear."

It may be that criminal behavior is more common among those with ADHD because they tend to have other personality disorders along with the condition. Oppositional deviant disorder (ODD) and conduct disorder are conditions often associated with ADHD, said Susan Smalley, a professor of psychiatry at the University of California, Los Angeles, and director of the Mindful Awareness Research Center there. People with conduct disorder may have antisocial behaviors, including criminal behaviors, she said.

In fact, several studies suggest that adults with ADHD who also have other conditions such as conduct disorder have a higher risk of criminal actions. Researchers at King's College London found that ADHD offenders were also more likely than others to have antisocial personality disorder, in which a person manipulates or violates the rights of others, according to a study published in October in the journal Expert Review of Neurotherapeutics.

What can be done for those prone to follow this path

Smalley and other researchers have suggested that expanding access to health care services for those with ADHD and other mental disorders would help.

Also, intervening when kids are young may be a key, Smalley said. It is important to accurately diagnose ADHD and then use a "strength-based" approach to treating it: Build on the child's strengths, while treating the challenging aspects of the condition.

It is critical, she said, to recognize that just like everyone else, people with ADHD have strengths and weaknesses. "I believe this moves the challenge of ADHD into the community more, so that we work on ways to shift our educational systems, etc., to better deal with the large variety of learning styles among our children."

Fletcher and his colleagues recommend the use of intervention programs and evaluations for steering susceptible individuals away from crime.

"I think the need to increase access to treatments for those with ADHD symptoms would be a valuable policy goal," he said. "Access can come through schools, typically. But some schools might not have the resources to assist all children with ADHD symptoms."

Many children with the condition function normally most of the time, but experience high levels of impulsiveness sporadically, Fletcher said. "Treatments can be very effective if they are followed as prescribed and augmented with parental supervision and support."

Pass it on: Left untreated, ADHD may increase a person's tendency to criminal behavior.

This article was provided by MyHealthNewsDaily, a sister site to LiveScience.