What types of ADHD are there?

There are three subtypes of ADHD

ADHD – inattentive
(commonly known as ADD) – characterised with difficulties staying focused and attending to daily, mundane tasks. Individuals may be easily distracted by irrelevant sights and sounds, bouncing from one activity to another or becoming bored quickly.

ADHD – hyperactive
inattention may not be as much as a problem, but behaviour will be more impulsive with hyperactivity commonplace.

ADHD – combined
this subset of ADHD is as the name suggests a combination of inattention and hyperactivity

What causes ADHD?

There is much debate as to the cause of ADHD and most experts would say ADHD is caused by several factors which include:

Biological:
MRI scans have shown that the brain functions are different in someone with ADHD. Children with ADHD show a delay (of about three years) in the development of the part of the brain that is involved in thinking, paying attention and planning.

There are also overall delays in the maturation of the outermost layer of the brain, known as the cortex and some abnormal growth in the corpus callosum, which is the brain structure that is important for the communication between the two halves of the brain.

Hereditary:
The genetic makeup of an individual can make someone more susceptible to ADHD. Research has shown that ADHD can run in families.

Environmental Factors:
Cigarette smoking, alcohol and drug usage during pregnancy has been linked to ADHD in children. There are also some studies linking ADHD in children to lead exposure¹. These factors impact on the way the brain develops as an embryo and in infancy.

There are also thoughts that early childhood trauma, such as a chaotic family life, neglect or abuse can impact on the way a child’s brain develops and this can increase the likelihood of ADHD developing.

Brain Injuries:
A very small percentage of ADHD cases are linked to brain injuries.

If you would like to talk to someone about arranging an ADHD assessment please call one of our experienced team on 0203 326 9160. We can often arrange an assessment within a few days and you do not need a GP referral.

¹ Nomura, Y et al Prenatal exposure to maternal and paternal smoking on ADHD symptoms and diagnosis in offspring. J Nervous Mental Disorder 2010 September; 198 (9): 672-8 PubMed PMID: 20823730; PubMed Central PMCID: PMC3124822