New Study May Open Doors to Breaking the Link Between ADHD and Addiction
Researchers hope that more effective treatments catering to one’s specific genetic makeup will emerge in the future.
The connection between ADHD and addiction has been well established, but the underlying reasons for the link are still not clear. Is there an organic, brain-based relationship between the two disorders, or could it be that the children who are treated for ADHD with stimulant medication become dependent on the drugs and grow up to become addicts? Or are people with ADHD self-medicating with street drugs and then becoming addicted to those drugs?
According to epidemiological studies, 4% to 5% of people have severe ADHD. Within this population, 50% also suffer from some kind of addiction, including nicotine. Even with nicotine factored out, a 2007 survey “found that more than 15 percent of adults with the disorder had abused or were dependent upon alcohol or drugs during the previous year. That’s nearly triple the rate for adults without ADHD,” according to Carl Sherman, PhD. Despite the clear need to figure out the underlying mechanisms of these diseases in order to treat them effectively, doctors have been reluctant to diagnose and treat adults with ADHD who also have a comorbid substance use disorder.
Recently, Dr. Melanie White of Australia’s Queensland University of Technology began a research project in order to map the genetic markers associated with ADHD. "I'm looking at genetic markers of symptoms of ADHD in adulthood as well as whether people have used a range of different types of substances, and the interaction between these genetic markers and aspects of the environment," she said. Specifically, Dr. White is examining dopamine, a neurotransmitter associated with reward-motivated behavior. Although ADHD and addiction are separate disorders, they often share a deficit in the functioning of one of the dopaminergic circuits, making diagnosis and treatment difficult.
Dr. White's hope is that the results of her study will lead to more effective, customized treatments in the future. "We hope to be able to effectively say 'this medication would be more effective for you because of your genetic makeup', or conversely 'we don't believe this medication would be a good idea because it may increase some risks for you down the track,’” she said.