The Science of ADHD: Research Update

ADHD has been in the news quite a bit this past week. Today we will discuss scientific current events relating to suicide and stimulant medication, drug addiction and ADHD, and the link between the disorder and childhood exposure to anesthesia. This is an opportunity for us to delve more deeply into the neurobiological nature of ADHD, to move beyond armchair psychology and into the nuts and bolts of scientific evidence.

Suicidal Ideation and Focalin

A few cases of suicidal ideation among teens taking the ADHD stimulant medication, Focalin, have prompted some experts to advocate putting a warning label on the drug. Before you throw your medication in the trash, there are a few things you need to know. During a 6-year period, there were 8 reports of suicidal ideation among children or adolescents who took the drug. Four of these appeared to be linked to use of the drug, since symptoms resolved once the medicine was stopped. The 4 patients were all boys and between the ages of 8 and 11. Approximately 1.8 million children had this medication prescribed over a 6-year period. So, while suicidal ideation is an incredibly serious issue, in this context it is also an incredibly rare one. No cases of actual suicide have been reported. What this situation does reinforce, however, is that many ADHD medications are incredibly powerful. Parents need to research side effects and watch out for them. Medicating your child should not be taken lightly.

Self-Control, Drug Addiction, and ADHD

A study in Science finds that cocaine addicts have abnormalities in areas of the brain involved in self-control. And these abnormalities appear to predate any drug abuse. Researchers discovered abnormalities in fronto-striatal brain systems implicated in self-control in both cocaine-dependent individuals and their biological siblings who have no history of chronic drug abuse; these findings support the idea of an underlying neurobiological component for stimulant drug addiction. This particular brain circuit seems to be involved in a lot of common disorders, such as ADHD, in which individuals struggle to control their response to stimuli that distract them . With this new evidence, the link between untreated ADHD and substance abuse becomes even clearer. Once again, research continues to mount that difficulties in ADHD derive from differences in the brain!

ADHD and Childhood Exposure to Anesthesia

Two recently-reported studies appear to show a link between the administration of anesthesia to children and an increased risk for developing ADHD. The data for these studies came from the Rochester Epidemiology Project. Researchers analyzed school records of children who were born between 1976 and 1982 in Minnesota. Out of the 341 cases reviewed in the studies, children with no anesthesia exposure or just a single exposure to anesthesia had ADHD at a rate of about 7.3 percent. Children who had two or more exposures had ADHD at a rate of 17.9 percent. Researchers also tried to adjust for other risk factors, such as gestational age, sex, birth weight, and comorbid health conditions. To put this information in context, ADHD risk appears to increase with numerous other experiential risk factors, including: fetal alcohol exposure, low birth weight, cerebral palsy, as well as early exposure to lead and other toxicants. Since ADHD is a neurobiological condition, it should come as no surprise that substances that impact the neurobiological environment carry the potential to play a role in the development of ADHD. However, these experiential factors are all rather uncommon. The greatest “risk factor” for developing ADHD is having a parent or sibling with the disorder.