Adult ADHD has a strong Genetic component, meaning it often runs in families. Studies have shown that individuals with a first-degree relative, such as a parent or sibling, who has ADHD are more likely to develop the condition themselves. Research suggests that the genetic basis for ADHD involves variations in several genes that are associated with the brain's dopamine system, which plays a crucial role in attention, reward, and motivation. These genetic factors likely contribute to the underlying neurobiological differences observed in people with ADHD. However, genetics alone is not the sole factor in the development of ADHD and environmental influences also play a significant role in shaping the disorder's expression.

While genetics contribute to the risk of developing Adult ADHD, environmental factors, such as prenatal exposure to toxins, premature birth, or lead exposure, can also influence the likelihood of developing the condition. Moreover, childhood experiences and home environments may interact with genetic predispositions to affect how ADHD manifests in adulthood. While family history can increase the risk, ADHD can also occur in individuals without a known family history, suggesting that a combination of Genetic and Environmental factors is responsible for its development.

As ADHD is increasingly understood as a lifelong condition, early identification and intervention are essential for managing the symptoms effectively throughout life.