When you have attention deficit hyperactivity disorder (ADHD), you often behave impulsively and are easily distracted, and you probably have difficulty concentrating and focusing on important tasks. These problems can take a toll on everyday life — if you’re a child with ADHD, your grades probably suffer, and if you’re an adult, you may find it difficult to perform well at work or sustain a healthy relationship. Sometimes estimates are that 5% of preschoolers and school-age children suffer from ADHD. For many of them, symptoms will continue into adulthood. It’s not completely clear what causes ADHD; researchers believe it may involve a chemical imbalance in the brain or possibly even physical differences in brain structure. It is clear that it runs in families: If you have a close relative with ADHD, your chances of developing it yourself are around five times greater than the regular population.
Celiac Disease and ADHD Linked in Studies
The evidence for an association between ADHD and celiac disease is fairly strong: children and adults with celiac disease do seem to have a higher risk of ADHD than the general population. In one study, researchers tested 67 people with ADHD for celiac disease. Study participants ranged in age from 7 to 42. A total of 15% tested positive for celiac disease. That’s far higher than the incidence of celiac in the general population, which is about 1%. Once they started on a gluten-free diet, the patients or their parents reported significant improvements in their behavior and functioning, and these improvements were backed up by ratings on a checklist physicians use to monitor the severity of ADHD symptoms. Another study investigated the incidence of ADHD symptoms in people newly diagnosed with celiac disease. It looked at 132 participants, ranging from toddlers to adults, and reported that “ADHD symptomatology is markedly overrepresented among untreated celiac disease patients.” Again, a gluten-free diet improved symptoms quickly and substantially—six months after starting the diet, most people had vastly improved ADHD symptoms.
Evidence Less Clear for ADHD and Gluten Sensitivity
Not everyone who has a problem with gluten has celiac disease—recent research has identified markers for non-celiac gluten sensitivity, a poorly understood condition that seems to involve a reaction to gluten but not the intestinal damage that characterizes the celiac disease. Gluten sensitivity may affect up to 8% of the population by some estimates. For people with gluten sensitivity, studies show it’s possible that gluten plays a role in ADHD symptoms, but it’s less clear how large a role it plays. In one large study, researchers looked at the effects of the gluten-free, casein-free (GFCF) diet on people with various autism spectrum disorders. They reported a statistically significant impact on certain symptoms including attention and hyperactivity but noted that they couldn’t say for certain that it came from the GFCF diet. They also couldn’t say if the effect might have stemmed from removing gluten or from removing casein from the participants’ diets. Anecdotally, parents of children with ADHD have reported improvements in behavior (some quite significant) when they placed their children on special diets, including a gluten-free diet. However, it’s difficult to definitely correlate those improvements with the dietary changes.
The Bottom Line
If you suspect gluten may be contributing to your or your child’s ADHD symptoms, what should you do? First, you should consider testing for celiac disease, especially if you or your child shows other celiac-related symptoms. Remember, not all symptoms involve your digestive system; celiac symptoms in children may involve something more subtle, such as short stature or failure to thrive. In most cases, your physician will use a blood test to screen for celiac disease, followed by endoscopy if the blood test is positive. If the tests are negative for celiac disease (or if you decide not to pursue testing), you may want to discuss dropping gluten from your diet or your child’s diet for a month or so to see if symptoms improve. To do this test properly, you’ll need to avoid gluten completely, not just cut back on it. If the symptoms are influenced by gluten ingestion, you should notice a change within that month.
