For the longest time, with focus on hyperactivity, ADHD was considered to be a boys' disorder. The initial criteria used to diagnose ADHD focused on hyperactivity until the late 1960's, when inattentive and impulsive behaviors were added. As we know, girls have a higher prevalence of inattentive behaviors. However, until recently, major research studies, especially those following ADHD across the life span, have focused on boys.

As a result, our information on how ADHD impacts girls is evolving, slowly but surely.

Rates of Diagnosis for Males and Females

So, what is the difference in diagnosis of ADHD between males and females?  The answer varies, depending on the source of the data and how it was collected. According to the Center for Disease Control website, parents reported that approximately 9.5% of children 4-17 years of age (5.4 million) were diagnosed with ADHD as of 2007. Boys (13.2%) were more likely than girls (5.6%) to have been diagnosed with ADHD.

However, and perhaps surprisingly, over time the ratio of males to females with ADHD evens out to 1:1. Why? Because females are more likely to be diagnosed during adolescence and adulthood.

Boys with ADHD tend to be easier to identify, as their boundless energy often disrupts activities and exhausts their teachers and parents.

Girls, however, tend to be quieter and better able to mask the kinds of difficulties ADHD causes. As a result, ADHD in girls is often overlooked – sometimes until middle school, high school or even adulthood.

In addition to differences around diagnosis, there are distinct differences in the way that ADHD shows up in boys versus girls. This is an area of emerging research, so always be on the lookout for new information.

While these are not hard and fast rules to the way that ADHD symptoms appear, a review of the literature of the differences in ADHD in girls and boys is reflected in this chart.

Girls

• More often demonstrate Inattentive tendencies
• Diagnosed at older ages
• Greater likelihood of internalizing problems
• Have more difficulties with friendships
• May have increased feeling of self-doubt
• Societal expectations of girls may result in less tolerance from adults
• Estrogen may impact effects of medication
• Symptoms often become worse in adolescence
• May work harder to “hide” their symptoms in an effort to meet expectations
• May exhibit more covert behavior like lying
• Are more likely to engage in self-harm, like cutting or suicide
• Higher rates of co-existing disorders like depression

Boys

• More frequently demonstrate Hyperactive tendencies
• Easily spotted at younger ages
• More externalizing, acting out problems
• More easily accepted by peers
• Self-concept may not be as affected
• Behaviors caused by ADHD may be tolerated because they are typical “boy” behaviors
• Less obvious impact of hormones
• Maturation may result in improvement in symptoms
• Less concerned about what others think
• May exhibit more overt, aggressive behaviors
• Less likely to internalize difficulties
• Higher rates of co-existing disorders like Oppositional Defiant Disorder and Conduct Disorder

Effects of Maturation

Maturation effects boys and girls with ADHD differently. Girls often have more problems during the teenage years, but the reasons are still unclear. It's not news that girls begin to develop earlier than boys. They have more unpredictable moods and behaviors based on hormonal changes. It is possible that increased estrogen and other hormonal fluctuations during the menstrual cycle can affect serotonin and dopamine, the feel-good neurotransmitters in the brain, and result in oversensitivity and emotionality (this is still under study). When that is coupled with the complex social dynamics of adolescent girls, the results can aggravate symptoms of ADHD. Also, since girls tend to be diagnosed later, and early interventions are not as common, their challenges are often not addressed before puberty.

On the other hand, maturation sometimes results in improvement in boys with ADHD because their physical hyperactivity seems to lessen with age. However, while boys' ability to attend may improve with age, they may show some increased risk-taking behaviors and feelings of invincibility in adolescence, possibly due to testosterone increasing with age.

Social Interactions

The research tells us that girls with ADHD are often rejected by other girls, both with and without ADHD.  Girls already may feel awkward and out of place among peers because of ADHD, and puberty can make those feelings more pronounced.  Girls with ADHD are often plagued with the feeling that they don't fit in, and have a far greater need than boys for relationship and emotional connection. Girls are expected to navigate social relationships based more on communication. If a girl has trouble attending to and responding to the complex give and take of conversation among girls, she may feel more and more disconnected.

Boys' interactions usually don't have the same level of complexity as girls'.  Boys often connect with other boys through sports and activities, so the social impact of ADHD is lessened.

Co-occurring Disorders

Often children with ADHD have additional diagnoses, like learning disabilities, depression or oppositional defiant disorder.  While studies vary on their findings, there are some general trends. Girls tend to have more internalizing disorders, like depression, eating disorders, and anxiety. Boys tend to have more externalizing disorders, like oppositional defiant and conduct disorders. In particular, girls are at higher risk for developing self-mutilation disorders, such as cutting or burning.

Regardless of the differences in the presentation of ADHD in boys compared to girls, one thing is certain. ADHD is a chronic disorder, requiring monitoring, treatment and management into adulthood.