Attention deficit hyperactivity disorder (ADHD) is one of the most common mental health disorders in children, affecting 7.2% of people under the age of 18 worldwide. Many of these children will still have ADHD in their teens and into adulthood.
ADHD is diagnosed based on the DSM-5 criteria, which include symptoms of inattention, hyperactivity, and impulsivity. But it’s becoming increasingly clear to researchers that the condition is also linked to self-control problems that affect the ability to regulate emotions.
For example, 2.1% of children diagnosed with ADHD also have a mood disorder such as depression, and 27.4% have an anxiety disorder. Many also experience outbursts of verbal or physical aggression.
These previously unstudied aspects of the condition are now providing new insights into what goes on in the brain of someone with ADHD, raising hopes for new and improved treatments.
If ADHD is not treated effectively, it can have a significant impact on a child’s mental health and well-being, as well as academic achievement. It can also affect parents and siblings, as well as other children in the classroom.
So what is the neural connection between ADHD and emotion? In our new study, published in Nature Medicine, together with colleagues from Fudan University in China, we have identified a common brain basis we call the neuropsychopathological factor (NP factor) that underlies the symptoms of many mental health disorders, from depression to ADHD.
Using a combination of neuroimaging, cognitive, and genetic data, we discovered that many mental health conditions can be linked to a single, genetically determined problem of “synaptic pruning.”
This process usually occurs in childhood and removes extra synapses (brain structures that help brain cells transmit electrical or chemical signals) to keep our brains functioning and connections between regions optimal.
This pruning problem may be a major reason why children with ADHD often have other mental health disorders. Ultimately, this leads to delayed development of the prefrontal cortex, which is responsible for the “cognitive control” of our emotions and behavior. This means that people with ADHD can struggle with their emotions.
Delayed development of the prefrontal cortex may also explain why children with ADHD often have cognitive impairments, such as problems with executive functions (such as planning, self-control, and working memory). But then so are children with depression and anxiety. So what is ultimately the root of the problem? One recent large study of 11,876 9- to 12-year-olds provides a clue. At the University of Cambridge, we found that cognitive impairment in children with more ADHD symptoms was related to attention problems rather than emotions.
Children with symptoms of anxiety and depression showed these deficits only if they also had attention problems. So it seems that one possible way to help cognitive development in children with ADHD or mood disorders is to focus on improving their attention.
Treatment Another way to learn more about ADHD is to study the effects of medications used to treat it. The main pharmacological treatment for ADHD is called methylphenidate or Ritalin.
Methylphenidate works roughly by increasing three chemicals in the brain: dopamine, serotonin, and noradrenaline. Dopamine can improve attention, learning, working memory, and motivation, while noradrenaline reduces impulsivity and increases focus. Serotonin is known to improve symptoms of anxiety and depression.
We know a lot about which areas of the brain these drugs target. Indeed, the dopamine system affects several regions of the brain.
One study found that methylphenidate treatment improved attention and that this was associated with an increase in dopamine in the brain’s ventral striatum (an area associated with reward and motivation). This means that the dopamine reward/motivation circuit in the brain is probably important in ADHD.
Another study showed that methylphenidate improved working memory, which is known to be affected by dopamine, and increased blood flow to the prefrontal and parietal cortex, which are important for executive function. This study suggests that cognitive control involving frontal regions can be improved by methylphenidate.
This also supports our finding that ADHD is associated with delayed development of the prefrontal cortex, making it more difficult to control cognitive function.
In addition, a follow-up study found that methylphenidate significantly improved emotional symptoms in adults with ADHD. However, we still do not know whether methylphenidate controls emotion in a top-down manner via the prefrontal cortex, whether it directly affects emotion processing itself, or a combination of both.
Moreover, it is now becoming clearer that a problem with emotion regulation is a core symptom of ADHD and not just a co-occurring problem. Thus, emotional dysregulation is an important treatment goal.
Cognitive behavioral therapy is effective in treating self-control problems and low mood. It should be offered to children with ADHD along with pharmacological treatment.
ADHD is is on the Rise As ADHD diagnoses are on the rise worldwide, so are methylphenidate prescriptions. In fact, according to the National Health Interview Survey, the prevalence of diagnosed ADHD among children and adolescents aged 4–17 years in the United States has increased from 6.1% to 10.2% over the past 20 years.
A study conducted in the United Kingdom showed that since 2000 until 2015, the use of ADHD medication has increased by almost 800%.
With the increasing use of technology and remote learning and working, more than ever, we are multitasking and dividing our attention rather than focusing it on one task at a time. It is possible that the prevalence of ADHD will increase further in the future as coping strategies become less effective and people seek help and eventually receive a diagnosis.
Ironically, some solutions may be technology-based, such as cognitive training using game apps on iPads or cell phones, such as Decoder, which has been shown to improve attention in young adults.
The more we learn about the brain basis of ADHD, the easier it is to treat it.
(This story was not edited by Devdiscourse staff and was automatically generated from a syndicated feed.)