What is ADHD?

ADHD is a complex neurobiological condition caused by an imbalance of some of the neurotransmitters in the brain. The condition is present from early childhood although diagnosis is not usually made until after the age of 5. It is pervasive (i.e. occurs in more than one setting) and often persists into adolescence and adulthood.

The exact causes of ADHD are unknown, but current research evidence suggests a complex interaction between genetic pre-disposition (or risk) and environmental factors. Many children with ADHD will have parents who have adult ADHD.

ADHD is common condition affecting approximately 5% of the population. It significantly interferes with everyday life. Although research is still continuing, findings show that -

  • There are differences in the development of the brain, particularly in the areas of the brain which affect alertness, executive function and the ability to control shifts from one activity to another.
  • Blood flow to the brain is often reduced to some areas at the front of the brain. These areas control functions such as attention, impulsivity (the ability to stop and think before acting), sensitivity to rewards and punishment, emotions and memory.
  • There are difficulties with the genes that regulate attention, learning and appropriate behaviour.
  • Problems with neurotransmitters (dopamine and norepinephrine for example) can cause the brain to be under active or inefficient in people with ADHD. It is neurotransmitters, which allow the chemical messages to move through the brain - so if there is too little or too much, messages are unable to complete their journey throughout the body. This can cause lack of attention, irritability, inappropriate and argumentative behaviour, difficulty with schoolwork - problems comprehending what is read, poor memory, poor organisation, sleepiness in class, and problems retrieving information from stored memory.

Previous page: Membership
Next page: Diagnostic Criteria