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Attention Deficit Hyperactivity Disorder

What is ADHD?

Attention Deficit Hyperactivity Disorder (ADHD) is a diagnosis that is classified according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). To diagnose ADHD we look at three symptoms: inattention, hyperactivity and impulsivity. These symptoms must be at a level that causes impairment for the child, adolescent or adult in their daily life for the diagnosis to be made. The occurrence of these three symptoms determines the type of ADHD diagnosed. Children and adults who have hyperactive and impulsive symptoms are referred to as ADHD, primarily hyperactive-impulsive subtype; those who exhibit mainly inattention are referred to as ADHD, primarily inattentive subtype (often still referred to as ADD); and those who have all three symptoms are referred to as ADHD, combined subtype. This is the type diagnosed most often.

Attention Deficit Hyperactivity Disorder (ADHD) is the most common psychiatric disorder diagnosed in children. It affects 5-9% of school-aged children. Approximately 8-10% of males and 3-4 % of females under the age of 18 years have ADHD. For those with ADHD in childhood, the symptoms will continue to be severe enough to qualify for a diagnosis in 80% of adolescents and in over 50% of adults the core symptoms will continue to cause impairment. Although there are some differences in symptoms and the occurrence of related disorders between males and females, the impact of the disorder on patients and their families is fairly consistent.

The symptoms and subtypes of ADHD and associated disorders change dramatically throughout the life cycle. Hyperactivity and impulsivity may decrease as patients get older, but the demands on their attention and other thinking skills may increase. Due to this, the primarily inattentive subtype of ADHD may not have been diagnosed in childhood, because symptoms are not as easy to spot as in the other subtypes, but may become more obvious in adolescence or adulthood. Many of these patients are females, which suggests that the prevalence rates may be higher in females during childhood than we previously recognized.


The History of ADHD

ADHD, or other disorders with similar symptoms, have been described for more than a century.  In the early 1900s, children with ADHD symptoms were labeled “brain damaged”. The symptoms of ADHD were thought to be caused by central nervous system injuries such as trauma or infection. By the 1960s, the term “minimal brain damage” was used to describe the disorder. The term “Attention Deficit Hyperactivity Disorder”, now used, more closely describes the symptoms of the condition. At this time, ADHD is recognized throughout the world as a condition that can be assessed, diagnosed and treated.

ADHD may seem to be more common today than in the past but this is largely due to the increase in research and media scrutiny. Research has encouraged awareness within the professional community, leading to better diagnoses. Media coverage, although not always accurate, has heightened public awareness of the condition.


How Do We Diagnose ADHD?

Contrary to popular belief, every child entering a doctor’s office presenting symptoms of inattention, impulsiveness and/or hyperactivity does not immediately receive a diagnosis of ADHD. A physician’s ability to evaluate other possible causes through observation and testing is very important. The diagnosis of ADHD is made by ruling out other reasons for the symptoms as well as looking at data that would support a diagnosis of ADHD.

The diagnosis of ADHD is based upon the ability to observe symptoms that seem to occur consistently enough that they could not be a coincidence. The physician will use parent symptom rating scales that will help him or her to diagnose the disorder with some level of certainty. Your child’s teacher will also be asked to complete these scales. The symptoms need to be observed in two different environments for ADHD to be diagnosed. For the diagnosis to occur, there must be at least some symptoms present before the age of seven and they must be present for at least six months. Your child should always have a physical exam performed, as well as a hearing and eyesight test, to rule out any physical reasons for the symptoms. It is also recommended that a psychoeducational assessment be done to determine whether other learning disabilities may coexist with the ADHD or be the cause of the symptoms. Once treatment is started, the symptoms should be monitored to evaluate the level of improvement.


The Cause of ADHD

ADHD is suspected to be a problem related to the hard wiring of circuits within the brain. There is most likely a chemical imbalance occurring, similar to other psychiatric disorders. Unfortunately, given the current tools that are available, we are not able to measure these chemicals nor  determine how the circuits are connected.  Since the blueprints used to determine these circuits are genetically created, we do know that ADHD is hereditary. Specific genes associated with ADHD have been discovered: dopamine transporter gene (DAT1) on chromosome 5 and dopamine receptor D4 gene (DRD4) on chromosome 11.

Research is pointing to a possible dopamine deficiency in certain parts of the brain. It is unclear whether individuals with ADHD do not produce enough dopamine, are unable to use it properly, or if they require more dopamine than the average person. The chemical serotonin may also be involved in some way. This chemical is very important in the brain’s ability to detect and possibly regulate the other chemicals. Noradrenaline, a substance that may act on our brain’s ability to adapt to stress, has also been implicated.  It may regulate our bodies’ “flight or fight” response.


The Treatment of ADHD

The treatment of choice is a combination of medication, special education put in place in the school system, and psychosocial interventions including individual, group, and family counseling. Psycho-education, or education about ADHD, is one of the most effective ways of treating ADHD. This may be the most important factor when looking at the effectiveness of long-term treatment and whether the patient will continue with their treatment. The more educated the family and the patient are about ADHD, the better they will be at implementing the treatment. The best approach to treating ADHD includes the following: regular follow-up visits with a medical practitioner; continued support for families with information about ADHD and its management; patient, parent and teacher training; special educational accommodations; and behavioral interventions combined with medication.

In uncomplicated cases of ADHD, medication management is fairly straightforward and typically effective with minimal side effects. The medication that is most often used to manage ADHD is stimulant medication. These drugs have been around for fifty years with thousands of research papers on their safety and efficacy. However, in the last five years, the development of time–released versions of this medication – that only need to be taken once a day – has significantly improved these same medications. These time-released capsules or tablets help prevent medication levels fluctuating during the day and carry the child through the whole school day and into the early evening. Some children do metabolize these medications more quickly than others and may not have coverage for as many hours. These medications are in a form that is difficult to abuse, and children often feel less stigmatized if they do not have to take medication at school. There is also a new medication available that is a noradrenergic agonist and not a stimulant medication that may also be considered by the physician. Doctors are now able to improve the main symptoms of ADHD in a very short period of time. However, a three-tier treatment approach is always recommended.