ADHD is one of the most common disorders diagnosed in children. Children show signs of this disorder before age seven, though some with ADHD remain undiagnosed until adulthood. There are significant differences in how the condition manifests in boys and girls, and this can affect how ADHD is recognized and diagnosed.

As a parent, it is important to watch for signs of all types of ADHD and to not base treatment decisions on gender alone. Never assume that the symptoms of ADHD will be the same for each child—two siblings can have ADHD yet exhibit different symptoms and respond to different treatments.

ADHD Behaviors in Boys and Girls

Research has shown that, in general, boys with ADHD have more “externalizing” symptoms (running, hitting, impulsivity), while girls with ADHD have more “internalizing” symptoms and side effects (depression, anxiety, low self-esteem). Studies also show that boys tend to be more physically aggressive, while girls tend to be more verbally aggressive (teasing, name calling, constant talking) (Rucklidge, 2010).

A 1997 study found that girls with ADHD had greater intellectual impairment, but lower rates of hyperactivity and externalizing symptoms compared to boys with ADHD (Gaub & Carlson, 1997). In addition, a 1999 study published in the Journal of the American Academy of Child and Adolescent Psychiatry found that girls with ADHD were more likely to have behavioral problems, mood and anxiety disorders, and impairment in social, family, and school functioning than non-ADHD girls (Biederman et al., 1999). These girls were also at an increased risk for substance abuse, panic disorders, and obsessive-compulsive disorders. However, they also found that rates of behavioral problems were lower in girls with ADHD than in boys with the condition, which may account for the lower rate of diagnosis in girls.

Recognizing ADHD in Girls

According to a survey by the U.S. Department of Health and Human Services, boys are twice as likely to be diagnosed with ADHD as girls (National Resource Center on AD/HD, 2010). It’s not that boys are necessarily more susceptible to ADHD, but rather that girls with ADHD are more difficult to identify. Girls with ADHD often have the inattentive type, whereas boys more often have the hyperactive/impulsive or combination type. The hyperactive/impulsive type is easy to identify at home and in the classroom because the child cannot sit still, fidgets, or behaves in an impulsive or dangerous manner. However, the symptoms of the inattentive type of ADHD are often more subtle. A girl with inattentive ADHD is unlikely to be disruptive in class, but will miss assignments, be forgetful, or just seem “spacey.” This can be mistaken for laziness or a learning disability.

Another reason why diagnosis is difficult in girls is the way they appear in relation to their peers. A study conducted by Michigan State University found that, when compared to the behavior of girls with ADHD, ADHD boys’ behavior tended to stand out more amongst their peers. Girls with ADHD were less likely to be identified as “different,” and thus less likely to be diagnosed.

Recognizing ADHD in Boys

Though ADHD is often under-diagnosed in girls, it can be missed in boys as well. Traditionally, boys are seen as energetic, so if they run around and bounce off the walls, it may be dismissed as simply “boys being boys.” In studies of children with ADHD, boys do report more impulsivity than girls, but it is a mistake to assume that all boys with ADHD are hyperactive or impulsive (Hasson & Fine, 2012). Boys with the inattentive type of ADHD may not be diagnosed because they aren’t physically disruptive.