At the first sign of attention deficit hyperactivity disorder (ADHD) — a messy backpack, fidgety in nature, slipping grades boys are medicated with Ritalin, Adderall or a similar variation. But what about girls? When the roles are reversed, it's often not quite so simple.

Until recently, little research had been done on how gender affects ADHD. New statistics reveal the vast discrepancy between the number of males with diagnosed ADHD and the number of diagnosed females.

According to a 2013 CDC report, 11 percent of school-aged children both boys and girls are affected by the mental disorder. You'd think such a prevalent disorder would be recognizable, right?

Boys are often diagnosed between the ages of 7 and 12 due to energetic and distracting behavior in the classroom, but recent studies show that symptoms in girls manifest as disorganization, inattentiveness and a tendency for daydreaming, rather than hyperactivity. The symptoms also manifest later in girls than in boys.

An Express Scripts study reveals the number of women who utilize ADHD medication after age 25 actually surpasses the number of men. In fact, between 2008 and 2012, the number of women aged 26 to 34 who utilized medication rose 85 percent.

"This is not about having trouble with their homework," clinical psychologist Dr. Ellen Littman told Quartz. "The outcomes for girls are horrendously negative compared to boys."

From a young age, girls are taught that successful women are planners, and planners must be organized. Strong women are depicted as "having it all together." It's understood that mothers are the calendar-keepers of the family who know when all the birthdays and appointments are, when bills are due, when it's time for an oil change, etc. When girls cannot achieve these ideals, they internalize their symptoms as personal flaws, and their self-esteem is affected tremendously.

The disorder can also be a red flag for other mental illnesses like anxiety and depression. Research shows anxiety and depression turn into low self-esteem and self-loathing, and the risk for self-harm and suicide attempts is four to five times higher for girls with ADHD.

According to a 2014 survey, nearly 50 percent of mothers of tween girls who have been diagnosed with ADHD reported that they first attributed their daughters' behavior to "normal" adolescent struggles. Another 59 percent reported that they initially hesitated to seek help from a doctor.

"We have a lost generation of women who are diagnosed with ADHD later in life, who have had to manage the condition on their own and deal with it on their own for the majority of their lives," Michelle Frank, a clinical psychologist and ADHD expert, told Quartz.

Oddly, while awareness of ADHD in women grows, evidence suggesting huge overdiagnosis in boys is being presented. That's not to say that millions of boys and men don't suffer from ADHD.

"It's important to remember that while we have to focus on increasing awareness and services to girls and women, boys and men are also profoundly affected by ADHD. We have a long way to go in addressing the immense stigma and gross misunderstanding that surrounds this diagnosis," Frank said.

Littman works with, and has studied, the impact of ADHD on high-IQ men and women, many of whom spent years masking their symptoms with their high abilities. As she tries to target whether ADHD is the issue, she asks whether they are "constantly in a state of being overwhelmed and frantic about coping with day-to-day basic things." Most burst into tears.

"These are the people least likely to be acknowledged and because of the shame of feeling smart, they don't feel they are entitled to help," she told Quartz.

Though medication is not a miracle fix, advances in therapy and medicine have made it possible for ADHD to be treated and managed.

Maria Yagoda wrote in the Atlantic about being diagnosed as a junior at Yale: "Medication is certainly not a cure-all, but when paired with the awareness granted by a diagnosis, it has rendered my symptoms more bearable — less unknown, less shameful."