There are thirty kids in your child’s class, fifteen girls and fifteen boys. Of the fifteen boys, it seems like half of them have diagnosed ADHD, as opposed to only one of the girls. Why is this so? You may have heard that boys are more likely to have ADHD than girls. Alternatively, you may have heard that girls are just as likely to have ADHD but much less likely to be diagnosed because they don’t share the same “hyperactive” symptoms as boys. Which of these is true?

According to Russell Barkley, Clinical Professor of Psychiatry and Pediatrics at the Medical University of South Carolina, both are somewhat true…and at the same time, neither one is fully accurate.

 “It used to be that girls were less likely to be diagnosed with ADHD,” Barkley explains. “They weren’t making as much ‘trouble,’ so they didn’t get referred for a diagnosis.” Nowadays, however, the gap has closed. More and more girls are being referred and diagnosed with ADHD, and it’s harder for them to slip through the cracks.

At the same time, in some ways the quote is correct. Even though referral and diagnosis of ADHD in girls has improved tremendously, there still do seem to be more boys diagnosed with ADHD than girls, at least during childhood. Young boys are four times more likely to have ADHD than their female counterparts; adolescent boys are still more likely than adolescent girls to receive a diagnosis; but surprisingly, adult men and women seem to have about an equal chance of having ADHD.

Why is that? The answer is unclear. Dr. Barkley did describe one fascinating possibility that may explain the discrepancy between males and females when it comes to ADHD.

ADHD: A Sex-Linked Disorder?

As we all learned in high school biology, males are essentially missing part of a chromosome. Females have two full “X” sex chromosomes, whereas males have only one full “X” chromosome in addition to a stumpy “Y” chromosome. The Y chromosome, in evolutionary thought, is considered somewhat defective. “Biologically, females are the norm and males are the deviation from the norm,” explains Dr. Barkley.

This explains more than just ADHD. In fact, many childhood disorders – including autism and learning disorders – appear more in boys than in girls. That may be explained by the fact that many of these disorders are partially sex-linked, which means that the defective Y chromosome makes them more likely to appear in boys.

So how does that explain the fact that the gap between males and females closes as we reach adulthood? According to Dr. Barkley, it could be that the genes for the phenotype of ADHD – its external symptoms – are sex-linked, even if other ADHD-related genes are not. “It’s important to understand that ADHD, like any of these disorders, is not just dependent on a single set of genes,” explains Dr. Barkley. If the genes that actually allow the ADHD to be expressed are on the Y chromosome, it may cause them to be expressed more quickly if they were on an X chromosome.

What Parents Can Do

So what can parents do if they think that their daughter has ADHD? Dr. Barkley suggests a five-step plan:

1)      Get a diagnosis. “Don’t self-diagnose your child,” warns Dr. Barkley. “Don’t decide that your child has ADHD based on information that you find online or anywhere else. Only a qualified professional can diagnose your child with ADHD accurately.” Of course, make sure that the professional you approach is qualified to give the diagnosis and has done extensive work with children who have ADHD.

2)      Consider medication. “Many people are scared of medication,” Dr. Barkley notes. “But giving your child medication for ADHD is no different than giving your child medication for asthma.” It is true that there is a small percentage of children with ADHD that do not need medication, and you can feel free to try alternative methods of treating the disorder. Keep in mind, however, that your child may need medication in order to function most effectively, and medicating is a completely legitimate route if necessary.

3)      Get to know your child. What works for another child may not work for yours, especially if the other child does not have ADHD. Once you understand how your child’s ADHD affects her, you can figure out how to help her with her struggles.

4)      Get support. All parents need a support network, but parents of girls with ADHD will find it especially helpful. Looking for other parents whose daughters have similar problems, or find an online support group. You can ask them for advice, encouragement, or references for professionals who they found helpful.

5)      As Steven Covey’s bestselling book says, it’s important to “sharpen the saw” – which means taking care of yourself. Take a break when you need it to refresh yourself, and do something that you enjoy. A refreshed, happy parent will find it much easier to help a young girl with ADHD reach her full potential.