Surprising findings about ADHD may help girls who are struggling

Researchers at NTNU have found new correlations between ADHD and anxiety, which are two major health issues among adolescents. The two disorders often co-occur in individuals, and recent findings now reveal that the relationship between them appears to be different in girls and boys.

There are several types of ADHD, and the researchers’ findings are related to one specific type called the inattentive type. A higher percentage of girls have this type of ADHD. Boys often have a different type of ADHD called the hyperactive-impulsive type. Some people can have both.

“First and foremost, we have identified a link between anxiety and inattentive type ADHD, and we find that this only applies to girls,” said Professor Lars Wichstrøm at the Department of Psychology. The research is published in the Journal of Child Psychology and Psychiatry. The study is part of Mojtaba Habibi Asgarabad’s doctoral work and is part of the Trondheim Early Secure Study (TESS).

This is the first time researchers have investigated—and demonstrated—that the relationship between ADHD and anxiety differs according to sex, and that it is linked to inattention.

“We assumed there were differences between the sexes, but we did not expect them to be so significant,” said Wichstrøm.

He emphasizes that they have studied inattention as a symptom of ADHD, rather than ADHD as a disorder.

The two disorders seem to reinforce each other. In girls, the prevalence of inattention increases the likelihood of more severe symptoms of anxiety disorders during childhood and adolescence. In addition, anxiety during adolescence increases the likelihood of the inattention worsening.

The researchers found no such correlation between inattention and anxiety in boys. However, they found that increased hyperactivity-impulsivity in the first few years of school increased the likelihood of developing anxiety.

Earlier detection

Anxiety disorders increase significantly during adolescence, especially for girls. The NTNU study concludes that early detection and effective treatment of inattention symptoms in girls can reduce the risk of anxiety later on in life. Similarly, interventions or treatment for anxiety can reduce the likelihood of attention deficit difficulties becoming more severe in young girls.

It is well known that ADHD and anxiety often co-occur in individuals. According to Wichstrøm, only a small part of this comorbidity can be explained by shared genetics between ADHD and anxiety. We also know that the intensity of ADHD symptoms and anxiety can vary over time.

However, we do not know why this is the case.

On average, 5% of children and adolescents have ADHD, both in Norway and in other countries where this has been studied.

Girls with inattentive type ADHD are often perceived as shy, introverted, absent-minded and daydreaming—or even lazy. As children, they often go under the radar because they rarely cause any trouble or disturb others. The only symptom they have is inattention, and it can be difficult to distinguish this from simply being “normally” distracted, disorganized, or forgetful.

This means that girls often receive the diagnosis later on in life. As a result, they miss out on interventions that might help limit the later development of anxiety, according to Wichstrøm.

Hyperactive-impulsive type ADHD is most prevalent in boys. It is easier to see and hear individuals who struggle with restlessness and hyperactivity, who cannot sit still or wait their turn. Thus, they tend to be identified earlier, receive a diagnosis, and get help more quickly.

Children who struggle with basic skills can experience exclusion, bullying and other stressful challenges.

“Personal and social challenges can easily lead to rumination, worry, anxiety and catastrophizing. It seems that girls are more vulnerable when they are exposed to negative life events or bullying. They are more likely to respond with depression than boys,” explained Wichstrøm, who has done extensive research on anxiety and depression among adolescents.

Researchers still do not know if there are any common factors underlying and influencing why some individuals develop both anxiety and ADHD. What they do know is that the older an individual is when diagnosed, the more common it is for them to have inattentive type ADHD.

“Generally, as young people approach puberty, the prevalence of anxiety increases significantly—especially among girls, and it is only at that point that their ADHD is also detected,” explained Wichstrøm.

Looking for early signs

The NTNU researchers hope their findings can demonstrate the importance of early detection of ADHD in children.

“Anxiety increases significantly in children as early as 12 years old. If we can identify inattention problems before that age, possibly as young as 8 years old, we may be able to reduce or prevent them from developing into anxiety,” said Wichstrøm.

The NTNU researchers emphasize the need for more knowledge about the intricate connections between sex, ADHD and anxiety. An additional step could be to confirm the findings they have made in an even larger study. Wichstrøm would like to see further research on the very youngest girls.

Wichstrøm is fully aware of the debate about the overdiagnosis of ADHD. He says it is quite possible that too many people may end up with a diagnosis.

“But we must still strive to actually detect ADHD where it exists and help those who have it,” he said.

The NTNU study is an observational study. It is based on information from 1,000 children born in 2003 and 2004 and their parents. The participants have been followed up every other year from the time the children were 4 years old until they turned 18. They are now young adults, turning 22 this autumn.