Inattention:
- Difficulty sustaining attention in tasks or play.
- Frequently making careless mistakes in school or work.
- Trouble organizing tasks or activities.
- Easily distracted by external stimuli.
Hyperactivity:
- Fidgeting or tapping hands and feet.
- Inability to stay seated in situations where it is expected.
- Talking excessively.
- Difficulty playing or engaging quietly in leisure activities.
Impulsivity:
- Interrupting others or blurting out answers before questions are completed.
- Difficulty waiting for one’s turn.
- Engaging in activities without considering the long-term consequences.
The exact cause of ADHD is not fully understood, but research suggests a combination of factors:
- Genetics: ADHD tends to run in families, indicating a hereditary component. Family studies indicate that ADHD is highly heritable, with genetics thought to account for a significant portion of the risk. Specific genes related to dopamine regulation and neurotransmitter function are often implicated in ADHD, though it’s typically influenced by multiple genes rather than a single one.
- Brain Structure and Function: Differences in brain anatomy, especially in areas controlling attention and impulse control. Brain imaging studies have shown differences in the size and activity of certain brain regions, particularly those involved in executive functions like planning, decision-making, and self-control. The prefrontal cortex, basal ganglia, and cerebellum are frequently cited in ADHD research, as these areas help regulate attention and impulse control.
- Environmental Factors: Exposure to certain toxins during pregnancy, premature birth, or low birth weight may increase risk. Certain prenatal and early-life factors appear to contribute to ADHD risk. These include exposure to nicotine, alcohol, or other toxins during pregnancy, as well as birth-related complications like low birth weight or premature delivery. Additionally, exposure to high levels of lead in early childhood has been associated with an increased risk of developing ADHD.
