What is ADHD?

Attention Deficit Hyperactivity disorder (ADHD) is a neurodevelopmental disorder,  characterised by a wide range of behavioural symptoms which include hyperactivity, lack of attention or concentration and a tendency towards impulsive behaviours.

Image Credit: Billion Photos / Shutterstock
Image Credit: Billion Photos / Shutterstock

ADHD commonly also presents with other physiological and psychiatric symptoms including sleep disturbances and learning difficulties. Contrary to the popular belief, having ADHD does not necessarily lead to lower intelligence (IQ).

The cause of ADHD is largely unknown, although there is evidence to suggest heritability, suggesting a genetic link. Other factors that may potentially cause ADHD also include being born prematurely and having a low birthweight. Alcohol and drug abuse during pregnancy can also be a contributing factor in addition to other disorders.

How is ADHD diagnosed?

Diagnosis of ADHD is usually made in infants/children. Since many of the symptoms of ADHD are present to a mild degree in many children, diagnosis using set criteria is important.
Most patients are diagnosed between ages three and seven. ADHD may also manifest in adulthood. Due to the lack of age-appropriate criteria and symptomatology, diagnosis in adults may be more difficult.

Assessment is usually carried out by a specialist after referral from your GP. These specialists may be psychiatrists, paediatricians or occupational therapists with expertise in ADHD.

There is no simple biological or psychological test for ADHD, and specialists often have to perform a variety of assessments before a definitive diagnosis can be made. Once other causes of symptoms are ruled out, and assessment has taken over a 10-week period (to see if symptoms improve naturally), a formal diagnosis can be made, and children can be enrolled in specialist groups to manage their symptoms.

Some key criteria for a diagnosis must be that the symptoms must have been continuously presented for over 6 months, before the age of 12, and symptoms being presented both at home and at school (to rule out teacher/parental control).

Types of ADHD and Symptoms

There are classically three different types of ADHD. This classification is based on the strongest symptom showed by the child.

Predominantly Inattentive (ADD; Attention Deficit Disorder) – This includes major symptoms like lack of attention, purposefulness to complete a given task, follow instructions and conversation and pay attention to smaller details. Distraction is common in such people.

Predominantly Hyperactive & Impulsive – Persons with this type of ADHD often fidget and talk more than necessary. They find it difficult to sit still for work, meals or school. In toddlers this may manifest as constant running, jumping and extra physical movements. This condition also manifests as impulsivity. The person may speak out of turn, for example, or grab things from others. This impulsivity also makes the individuals prone to accidents and injuries, especially in later life, as they appear to have a little or no sense of danger at all.

Some people may have a combination of both types – these people show a mixture of symptoms of both types.

Children with ADHD are also prone to have other mental health related conditions and illnesses, such as anxiety, depression, autistic spectrum disorder and in some cases Tourette’s syndrome. Various learning disabilities are the most common, such as difficulty with spelling, reading (dyslexia), writing or math. Some children may show Oppositional Defiant Disorder which is characterized by stubborn nature or rebelliousness.

In some cases, children with ADHD may also have conduct disorders that cause them to do wilful harm to persons or properties (antisocial behaviour). These children run a risk of getting arrested for illegal activities. These mental health problems need to be diagnosed and addressed while treating patients with ADHD.

How many people does ADHD affect?

In the United Kingdom, ADHD affects approximately 3-9% of all school-going children and young people.

According to the American Psychiatric Association in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) 3-7% of school aged children in the United States have ADHD. However, studies have shown higher percentages in communities. ADHD affects 2% of the adult population worldwide. ADHD is also more common amongst males.

Impact of ADHD

The impact of ADHD on the child can be enormous. Children with ADHD have 3 times higher problems with their peers than those who do not have ADHD.

Parents of these children are 10 times more likely to report that the condition interferes with forming friendships. A study has shown that children with ADHD are more likely to suffer non-fatal injuries. In addition those with ADHD are also more likely to suffer major injuries, emergency department, hospital in or outpatient admissions.

When older, ADHD patients are at a higher risk of drink-driving, automobile accidents and violations of traffic rules.

Apart from this, ADHD also implies a heavy economic burden on the country. The cost includes not only those for ambulatory care visits but also other health care costs, costs of admissions, medications, therapy and cost of work loss for patient as well as family members and parents.

Those with ADHD have increased chances of having at least one day off for sickness per month compared to healthy workers. Studies estimate that ADHD is the reason for 143.8 million lost days of productivity annually.

Are there any cures for ADHD?

At present there are no definitive cures for ADHD. Around two thirds of the children with ADHD continue to have symptoms of the conditions at the age of 25, although adult ADHD is poorly researched and effects may persist through life.

Symptoms may, however, be controlled and learning difficulties may be overcome using medication, behavioural, psychological and social therapies from a young age.

Further Reading

Last Updated: Jan 21, 2019

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


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