Understanding the Causes of ADHD: Genetics, Risk Factors, and Key Contradictions

When parents hear that their child has ADHD, one of the first questions that arises is: “What caused this?” The answer is never straightforward. ADHD does not stem from poor parenting, bad behaviour, or too much screen time. Instead, research points to a complex interplay between genetics and environment. ADHD is one of the most heritable neurodevelopmental conditions, but it is also shaped by factors before, during, and after birth that influence how a child’s brain develops. Just as importantly, ADHD is full of contradictions — traits that can be frustrating one moment and inspiring the next.

Genetics: Inheriting ADHD Risk

Genetic studies, including those on families, twins, and adopted children, consistently show that ADHD is highly heritable. However, there is no single “ADHD gene.” Rather, the condition arises from the influence of multiple genes that together alter brain structure, neurochemistry, and connectivity.

Having a relative with ADHD is one of the strongest predictors. Psychiatrists Edward Hallowell and John Ratey note that when one parent has ADHD, their child has about a one in three chance of developing it. When both parents have ADHD, the likelihood increases to two in three. These numbers highlight why ADHD so often runs in families — and why parents who receive a diagnosis for their child sometimes begin to recognise traits in themselves.

Environmental Risk Factors

Genetics lay the foundation, but environment can shape whether and how ADHD emerges. Research has identified a range of prenatal and early childhood factors that can increase risk. These include smoking, alcohol use, or drug exposure during pregnancy, all of which have been linked to attentional difficulties later in life. Exposure to toxins such as lead or mercury also plays a role, particularly in early childhood.

Complications at birth — such as prematurity, low birth weight, or lack of oxygen — have been associated with ADHD, as have early brain injuries or infections, although most children with ADHD do not have a history of trauma. Maternal obesity during pregnancy has also been identified as a contributing factor. Beyond medical risks, social and relational factors matter too. Children who do not experience secure early attachment may later show signs of hyperactivity and inattention.

More recently, researchers have raised questions about the potential effects of electromagnetic fields from powerlines, Wi-Fi, and mobile phones. While the science is far from conclusive, it reflects how environmental influences remain an evolving area of ADHD research.

The Contradictions of ADHD

Beyond its causes, ADHD is best understood through its paradoxes. The condition often presents with traits that appear contradictory yet coexist in the same child. Take focus, for example. Many children with ADHD struggle to stay on task, drifting away during lessons or conversations. Yet the same child may spend hours intensely absorbed in drawing, coding, or gaming. This phenomenon, known as hyperfocus, reflects how ADHD is less about a lack of attention and more about a difference in how attention is regulated.

Academic performance reveals another paradox. A child may score highly on intelligence tests, demonstrating clear capability, yet chronically underperform in school due to disorganisation or incomplete work. Similarly, time management often swings between extremes. Children may procrastinate endlessly, appearing “lazy,” only to complete a major assignment in a last-minute burst of productivity.

Emotionally, ADHD can be just as contradictory. Some children radiate humour, charisma, and generosity, yet are intensely sensitive to criticism or rejection. This vulnerability, known as rejection-sensitive dysphoria, can leave them devastated by even small perceived slights. Socially, they may desperately want to connect with peers but struggle to do so because of impulsivity, awkwardness, or self-doubt.

Even traits like impulsivity, often seen as a weakness, can coexist with remarkable creativity. Quick decisions and restless energy sometimes fuel imaginative, out-of-the-box thinking that others would not have considered. Stubborn independence, too, can lead to both frustration and resilience: while children may resist help even when they are struggling, this determination can also translate into persistence when channelled positively.

ADHD or VAST? The Question of Modern Overstimulation

A related concept that has recently entered the conversation is Variable Attention Stimulus Trait (VAST). Proposed by Hallowell and Ratey, VAST is not a disorder but a description of how constant exposure to overstimulation in modern life — especially through technology — can produce ADHD-like behaviours. In many ways, VAST mirrors ADHD, from distractibility to impulsivity, though its roots are environmental rather than genetic. Interestingly, many of the same therapeutic approaches that help with ADHD, such as structure and mindfulness, are also effective for people experiencing VAST.

Conclusion

The causes of ADHD cannot be pinned down to a single factor. Instead, the condition arises from a dynamic interplay of genetics and environment, shaped by influences both biological and social. What makes ADHD unique, however, is its paradoxical nature. The same brain that struggles with attention may also produce moments of brilliance; the same child who procrastinates may also demonstrate bursts of productivity and creativity.

For parents, understanding these complexities is empowering. ADHD is not a flaw or a failure but a different way of being in the world. With the right support, children can learn to manage the challenges and harness the strengths that come with their neurodivergence.

At Psyche Vitality, we help families navigate these complexities through remote ADHD assessments, therapy, and parent support. Book a consultation today to gain clarity and start your child’s journey toward confidence and resilience.