Girls undiagnosed with ADHD can be self-destructive by their mid to late teens. They’re also more likely to present with co-morbid, complex conditions at this late stage. So, why are so many girls ‘flying under the radar’ when early intervention for this childhood neuropsychiatric disorder leads to positive outcomes?

Child psychiatrist Dr Alberto Veloso says girls are less likely to be diagnosed with ADHD because they don’t often exhibit behaviour that draws attention.

“Boys are more likely to exhibit externalising behaviours which attract the attention of teachers and other carers. Boys are also more likely to be hyperactive [due to] a developmental process that relates to the number of dopamine receptors boys have at a certain age. 

“By nature, girls are more likely to exhibit internalising symptoms such as withdrawing from their environment. Their inattention may cause them to miss information in class, be easily distracted, be forgetful and show difficulties with planning skills or strategy. These are subtle symptoms that are easily missed.”

Unrecognised and untreated, girls without a diagnosis can experience anything from subtle difficulties at school to major mental health conditions and damaged relationships, says Dr Veloso.

“Mental health problems develop because the young person often feels that they're not as good as their peers, especially if their academic results drop. This can lead to self-esteem problems which can become a depressive disorder. 

“The other great problem is that these young people are often seen as ’not trying hard enough’ and comments like ‘if they would only apply themselves’ are commonly used.  This message of ‘you’re not good enough’ becomes internalised by the young person and can become their definition of themselves.  This can cause major problems in the relationships they form later in their life.” 

According to paediatric psychologist Deirdre Brandner, many factors lead to underdiagnosis in girls, including outdated diagnostic criteria, stereotypes and societal expectations.

“We know that only girls with very extreme symptoms are diagnosed, and it is more likely if it is presenting [with] another disorder, such as autism or anxiety.

“This may occur because the diagnostic criteria are based on observed boy’s behaviour. Much research has focused on diagnosed ADHD, but if fewer girls are diagnosed, inclusion data is limited.”

When we consider stereotypical symptoms, inattention is usually missed in boys and girls. But girls are more likely to have inattentive type ADHD, says Brandner.

“These symptoms are more internalised and easily missed. They may include difficulty focusing, daydreaming, forgetting things or being poorly organised. We may describe these students as being ‘all over the shop.’”

As a result, girls are diagnosed late (or not at all), leading to an increased risk of comorbid mental health conditions and, at best, a lifetime of underachievement and frustration.

“Girls with both the hyperactivity and inattentive type of ADHD that is not being managed can become quite self-destructive during their mid to late teens.  This can lead to anxiety and depression.

“Studies have shown that undiagnosed ADHD girls may present with substance use disorder, eating disorders or borderline personality disorders.

“If a child has had a lifetime of not being understood or not having insight into how their brain works, there can be negative outcomes. We can see young girls with great cognitive and creative potential that never gets realised.

“Adult females may present with low self-esteem; they develop coping strategies to compensate, but these are not always logical. They can also find it hard to identify their wins in life as attributable to internal factors, instead considering luck or being in a good job with others as the reason behind achievement.”

Jocelyn Brewer, diagnosed with ADHD at 34, can relate, saying she was often bored and struggled to pay attention as a child and still doesn’t feel like she’s achieved a lot, despite her success.

“I have always been acutely aware of time – my first experience of it dragging was from the ticking clock on 60 minutes. For a kid, 60 Minutes is the world's most boring show.

“I was annoyed to learn there are 60 minutes in an hour and that yes, the adults' show would be going for another 59 circuits of the second hand and no, I could not change the channel. Why couldn't they just say all their boring things faster?

“People who know me laugh when I say I don’t feel like I have achieved much. It’s true - that’s what I feel.”

A sentiment felt, despite running one of the biggest debating programs in Australia, producing eight theatre shows in five years, writing a thesis on internet addiction, completing a psychology registration, travelling overseas several times and starting a whole new career.

“But I don’t have a huge sense of accomplishment. It’s just stuff I’ve done and only a fraction of what I want to do.”

After diagnosis and treatment, Brewer says she’s more focused, productive and present for people.

“I can work with more direction and purpose; my task completion has skyrocketed … I listen more authentically to people and relate better and more deeply. I’m not a zombie, nor a speedhead.

“I look forward and get excited by what’s next. I get very excited. But now, it’s a different kind of excitement – the kind I feel like I can sustain. Now I’m the turtle, not the hare.”

Neurodiversity expert Dr Jillian Stansfield says the stigmatising and misleading notion that ADHD is a ‘naughty boy’ condition is finally beginning to wane.

“There is an increase in the number of females being diagnosed with ADHD than previously due to better understanding and education.

[We’re also seeing] “female celebrities, such as Australian comedian Celeste Barber, sharing their ADHD diagnosis to reduce the stigma and increase awareness of the condition.”

ADHD is part of the neurodiversity model and has traits that overlap with autism, which can mask symptoms and make diagnosis more difficult in girls, says Dr Stansfield.

“ADHD presents differently in females at a young age. Like autism, traits of ADHD-presenting girls may be masked by the co-existing symptoms of depression, anxiety and trauma.

“It’s no wonder there are links between ADHD and autism. The ratio of males and females diagnosed with ADHD is similar into adulthood, close to 1:1.”

Education is crucial for all caregivers, educators and health professionals if we are to diagnose girls earlier, explains Dr Stansfield. 

“Continuing professional development (CPD) opportunities of the different clinical presentations in girls and women will assist mental health providers, teachers, and parents in identifying ADHD at an earlier age.

“We need to work collaboratively to share understanding and awareness through education to counteract the stigma and the myths associated with ADHD.”