ADD/ADHD occurs in an average of 5-12% percent of all children worldwide. ADHD is predominantly childhood-onset and can persist into adolescence and adulthood. It is characterized by a continuous and combined pattern of inattentive, hyperactive and impulsive behavior, and is often comorbid with other psychiatric disorders. Roughly half of all people with ADHD also have symptoms of anxiety, depression, OCD, learning disabilities, or another related condition.

Patients with ADHD have impaired academic, executive and social functions. Research indicates the strong genetic influence on ADHD with estimated heritability ranging from 75% to 91%. 40-50% of children with ADHD have at least one parent with ADHD and 30% have a sibling with the condition.

ADD and ADHD are complex neurobiological disorders in which neurotransmitters, the chemical messengers of the brain, do not function properly. Researchers believe this is because there is a deficit of the neurotransmitters norepinephrine, dopamine, and serotonin.

Researchers at The National Institute of Mental Health (NIMH) have used PET scans on adults with ADHD and found there is reduced blood flow and activity levels in these brains when they were working on thinking tasks. In addition the white matter that carries messages between neurons, is also smaller. But there is no indication of brain damage.

NIMH researchers have recently reported a three year delay in the brain maturation of those with ADHD, leading them to think and act like much younger people. This delay is most prominent in regions at the front of the brain’s outer mantle (cortex), important for the ability to control thinking, attention and planning.Sometimes referred to as the "CEO of the brain", these cognitive skills are known as executive functions.

The executive functions are:
-non-verbal working memory
-verbal working memory
-emotional self-regulation
-planning and problem solving

Anyone who exhibits the classic symptoms of ADHD will have difficulty with all or most of the seven executive functions. For example, problems with inhibition for someone with ADHD lead to impulsive actions and a lack of emotional regulation leads to inappropriate outbursts.

There are three types of ADHD:
-ADHD predominantly hyperactive and impulsive
-ADHD predominantly inattentive, without hyperactivity (often referred to as ADD)
-ADHD combined type (hyperactive, impulsive and inattentive)

Symptoms are different in each person, ranging from mild to severe leading to variability in skills and maturity levels.

25% of those with ADHD will find it does not cause them major problems in adulthood, often because they choose a career that is compatible with their personality, their symptoms become less severe with age or the adult learns to compensate. 50% will cope most of the time, but their ADHD will cause problems at times. 25% will experience serious lifelong challenges.

What are the signs of ADHD?

Inattentive symptoms:
• Difficulty paying attention to details/makes careless mistakes
• Has difficulty sustaining attention
• Often does not seem to listen when spoken to directly
• Often unable to follow through on tasks
• Avoids tasks that require sustained mental effort
• Easily distracted
• Forgetful

Hyperactive/Impulsive symptoms:
• Fidgets or squirms
• Has trouble staying seated
• Excessive running or restlessness
• Often talks too much
• Blurts out answers
• Difficulty awaiting turn
• Interrupts conversations

ADHD may look differently in adults than children and teenagers:
• Difficulty paying close attention at work
• Struggle to organize daily activities and miss deadlines
• Have difficulty initiating and completing projects
• Not seem to listen when spoken to
• Have poor time management so they are often late
• Be forgetful, lose important belongings such as house keys
• Feel restless
• Frequently interrupt conversations with colleagues, friends and family
• Make impulsive decisions
• React in an overly sensitive way to criticism?
• Overpromise and underdeliver?
• Get bored easily?
• Constantly chatter, even when inappropriate?