An inattentive brain

The human brain is an intricate organ with approximately 86 billion interconnected neurons. These neurons continuously transmit electrical impulses, enabling us to perform multiple daily tasks. It is common to experience that multitasking during a conversation can overwhelm neural connections, leading to distractions, loss of focus, and an increased likelihood of mistakes.

Imagine a condition where attention to detail becomes challenging, leading to careless mistakes in schoolwork, issues with focus, and task avoidance. It also involves forgetfulness, hyperactivity, and impulsiveness. In India, about 5-6% of school-going children are affected by this condition, with a slightly higher prevalence in boys than girls. Known as Attention Deficit Hyperactivity Disorder (ADHD), this neurobehavioural neurodevelopmental disorder typically starts to impact individuals before the age of 12.

People with ADHD often struggle with focus and self-control, affecting their daily lives. In children, it can impact academic success, while in adults, it can create challenges in the workplace and personal relationships.

The earliest reference to ADHD-like symptoms dates back to Hippocrates (460–375 BC), who described patients with short attention spans and quick reactions, attributing it to an “overbalance of fire over water.” Centuries later, in 1798, Scottish physician Sir Alexander Crichton wrote about a “disease of attention,” noting mental restlessness and difficulty focusing. Around the same time, philosopher John Locke also described students who struggled to keep their minds from wandering.

Understanding attention

Dr Sridharan Devarajan, Gore Subraya Bhat Chair Associate Professor of Digital Health at the Centre for Neuroscience, Indian Institute of Science (IISc), Bengaluru, has been studying the components of human attention and how they are regulated within the brain.

Dr Sridharan’s research explores how the brain focuses on a specific object while ignoring distractions in the background. According to him, when we pay attention to something, the brain processes and extracts valuable content from it, a process known as “sensitivity.” The brain also prioritises certain information over others when making decisions, which is referred to as “bias.”

For example, in heavy traffic, your brain focuses on the car ahead to track its movements closely (sensitivity), while ignoring adjacent vehicles (bias). These components of attention guide eye movements and visual navigation. Recent peer-reviewed studies from his team have identified brain regions involved in these attention components. Two 2024 studies revealed how diverse groups of neurons in the brain, particularly in area V4, signal attention and eye movements independently. Further research identified the right posterior parietal cortex (rPCC), a brain region damaged in patients with “neglect,” as regulating attention bias. The latest study found that “attentional blink” (when a person fails to notice a second object that quickly follows the first) results from a network connecting the frontal and posterior parietal cortices.

Understanding the pathways and components of attention is essential for pinpointing which specific parts of the brain fail in attention disorders like ADHD.

The wiring problem

Researchers suggest that ADHD symptoms may stem from disrupted neural connections between the frontal cortex, which controls attention and behaviour, and subcortical regions involved in learning, movement, and emotion. The frontal cortex supports executive functions such as working memory and task management, and in ADHD, these connections are impaired, affecting cognitive control. The amygdala, responsible for processing emotions, also contributes to impulsivity and over-reactivity when its connections are disrupted.

Can ADHD go unnoticed?

Dr Eesha Sharma, Associate Professor at the Department of Child and Adolescent Psychiatry, NIMHANS, explains that diagnosing ADHD may require multiple sessions with the child and parents for a thorough clinical evaluation, rather than a single structured assessment.

The Covid-19 pandemic may have led to more ADHD diagnoses. With the shift to online learning, children had fewer opportunities for physical movement, making inattention, hyperactivity, and impulsivity more noticeable.

Traditional classroom adjustments and support were lost, and coping mechanisms like breaks or peer interactions were no longer available. Similarly, long virtual meetings with adults may have highlighted previously unnoticed inattention issues.

Unlike other mental disorders with persistent symptoms, ADHD may go unnoticed if the context does not demand specific developmental abilities. Additionally, its core components — inattention, hyperactivity, and impulsivity — can vary across different situations. Dr Eesha notes that ADHD symptoms typically emerge by age 12. However, they may go unnoticed until higher academic demands reveal underlying difficulties, leading to a diagnosis.

ADHD also has a strong genetic component, with several families having multiple affected members.

Treatment approaches

ADHD often begins in childhood but can be chronic, continuing into adolescence and adulthood with varying levels of impairment.

Treatment should include components like psychoeducation, academic support, school accommodations, symptom management, parental practices, and the treatment of co-occurring disorders. As the patient matures, treatment approaches are likely to evolve.

The recommended treatment for children under six years old begins with behaviour management, such as parent training, and medication may also be used. Psychostimulant drugs, like Methylphenidate, are commonly prescribed. Before starting medication, it is essential to discuss potential benefits and side effects with parents.

Dr Eesha advises that early intervention and a supportive environment can significantly enhance a child’s development and well-being, as ADHD is a developmental condition.

Activities that support brain development also enhance attention and self-control. Parents should allow children ample free play, as it fosters natural brain growth and development. Over-coaching every activity can hinder self-directed learning and independence.

 Provide more human time and delay the introduction of gadgets.

 Encourage outdoor playtime daily.

 Ensure the intake of nutritious, home-cooked food.

 Maintain a healthy and happy home environment.

(The author is a consultant haemato-oncologist with a special interest in stem cell transplantation at Royal Wolverhampton NHS Trust, UK. He can be reached at [e-mail].)