Many kids have trouble sitting still or paying attention for long periods of time. But when required, they are able to focus and complete tasks simply, such as chores and homework. A small percentage of children have difficulty focusing at all and are considered to have ADHD. ADHD stands for attention deficit hyperactivity disorder. People with ADHD handle neurotransmitters in the brain differently, making it hard to perform tasks like organizing, following rules, and holding interest.

ADHD starts in early childhood as the brain is developing, although sometimes it is not diagnosed until adulthood. Up to five percent of children are affected.

The Cortex

ADHD is a condition believed to start in the brain. The human brain can be broken down into three sections; the forebrain, the midbrain, and the hindbrain. The cortex is in the forebrain and is believed to play an important role in ADHD. The cortex is a thin layer of tissue, also known as gray matter, that covers most of the brain. It is responsible for the higher functions of humans such as learning, memory, and judgment.

Forebrain

Not only is the forebrain the largest part of the brain, it is also the most intricate. The forebrain consists of the cerebrum, thalamus, hypothalamus, and the limbic system. The cerebrum is important to mental health because it holds the essential parts of our personality, including emotion, personality, intelligence, and memory. The cerebrum is split into left and right halves known as hemispheres. The left side is believed to be the logic side, while the right side is the creative side.

Each hemisphere has a surface known as the cerebral cortex, or grey matter. Information gathered by your senses travels from the spinal cord to the cerebral cortex. This information is then transmitted to proper parts of the nervous system that help you react to a situation.

Inside the forebrain, the thalamus acts as a relay of information from the senses to the cerebral cortex. The hypothalamus deals with many automatic functions, such as appetite, sleeping, pulse, and temperature. Finally, the limbic system controls emotions, memory creation, learning, and decision-making.

Research suggests that the size of the cortex is related to ADHD. Children with ADHD seem to have a smaller cortex by seven percent in both volume and surface area. In addition, there were fewer folds in the cortex. 

The posterior temporal cortex and inferior parietal cortex control attention and impulse. The gray matter density in this area was measured in studies to determine its correlation to ADHD. The results showed the levels to be lower in children with ADHD. White matter levels were also reduced in ADHD children who did not receive treatment.

Neurons are cells in the nervous system that carry information through an electrical process. They are responsible for giving the brain the necessary information to regulate the body. Inside a neuron is a neurotransmitter, which ‘excites’ a nearby neuron through electrical impulses. The space between neurons, or synapse, allows neurotransmitters to pass from neuron to neuron. This transfer of neurotransmitters allows information to move through the nervous system.

Dopamine and ADHD

The key culprit for ADHD is believed to be the neurotransmitter dopamine. Dopamine not only helps the brain control the body’s movement, it also regulates information in the brain.

Dopamine also acts as a “reward” system by releasing during a pleasurable activity to signify enjoyment. People with ADHD have shown a lower level of dopamine in the brain. Because dopamine is linked to reward and motivation, it is believed the reduced levels interfere with a person’s ability to concentrate.