top of page
Doctor and Patient



What is Attention Deficit Disorder/ Hyperactivity (ADHD) ?

According to DSM V diagnostic criteria, Attention Deficit Disorder/ Hyperactivity (ADHD), symptoms of ADHD include inattention symptoms and hyperactivity. The symptoms should have been observed for at least 6 months and noticed before the age of 12, across at least 2 different settings (such as home and school). The symptoms may affect school, work and social functioning

1) Inattention:

  • Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.

  • Often has trouble holding attention on tasks or play activities.

  • Often does not seem to listen when spoken to directly.

  • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).

  • Often has trouble organizing tasks and activities.

  • Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).

  • Often loses things necessary for tasks and activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).

  • Is often easily distracted

  • Is often forgetful in daily activities.


2) Hyperactivity and Impulsivity:

Often fidgets with or taps hands or feet, or squirms in seat.

  • Often leaves seat in situations when remaining seated is expected.

  • Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).

  • Often unable to play or take part in leisure activities quietly.

  • Is often “on the go” acting as if “driven by a motor”.

  • Often talks excessively.

  • Often blurts out an answer before a question has been completed.

  • Often has trouble waiting their turn.

  • Often interrupts or intrudes on others (e.g., butts into conversations or games)


Based on the types of symptoms, ADHD is further classified into 3 groups /presentations:

  1. Combined Presentation

  2. Predominantly Inattentive Presentation

  3. Predominantly Hyperactive-Impulsive Presentation


These symptoms often affect child’s daily activities, school and social relationships. These may lead to emotional problems and low self-esteems in some patients. The symptoms can last into adulthood, which might cause problems at work, conflicts with others, and impulsive behaviors such as fighting and substance abuse. In the past era when public awareness of ADHD was lacked, these children often being labelled as ‘lazy’ or naughty’. With the increased awareness of the symptoms, early recognition and prompt intervention often has good outcome.

Is ADHD a common disorder?

Around 9.4% of children was affected by different extent of ADHD according to data from CDC (Centre of Disease Control and Prevention) in 2016. Boys are more frequently affected than girls (boys 12.9%, girls 5.6%). In Hong Kong, the ratio of boys to girls in new cases of ADHD in Child Assessment Service is around 3 to 1.

What causes ADHD?

ADHD is caused by a combination of different factors, while genetic cause is part of it. The chance of ADHD is higher for those with close family members such as parents or siblings having ADHD.

Many researchers found variation in brain structures or function in persons with ADHD. They are more often to have smaller brain volume, altered function of forebrain and cerebellum, smaller volume of basal ganglia, and imbalance in neurotransmitter such as dopamine. These variation in brain structures or functions have crucial effects to our executive function and memory. These accounts for the symptoms of inattention/hyperactivity, behavioral and emotion problems, weak organization skills and executive functions.

Parenting and nurturing environment would not cause ADHD, but they would affect the severity of symptoms and outcome.

How would ADHD affect my child?

  • Childhood:

    Children affected by ADHD may have problems in learning and are more prone to injuries due to accidents. They may have problems in making friends and have more interpersonal conflicts due to their impulsiveness. Emotion problems such as anxiety and depression are more common among them due to difficulties and failure in school and social relationships. Other developmental problems such as dyslexia, developmental coordination disorder can occur at the same time and makes their learning and daily functions more challenging.

  • Adulthood:

    If the symptoms of ADHD were not well managed or ADHD was undiagnosed, the symptoms will persist into adulthood, and they are at higher risk of having conflict with others, substance abuse and impulsive behaviours.


What are the treatments for ADHD?

Many studies had demonstrated combined treatments (medication and behaviour therapy) are more effective than either of it.

Children above 6 years of age with disabling symptoms may benefit from medication, which has shown to improve attention and reduce hyperactivity problems. Learning problems and oppositional behaviours should be managed by cognitive behaviour therapy, combined with effective parenting skills and school supports.

For children below the age of 6 years, behavioral therapy is the mainstay of treatment. The aim of behavioral therapy is to reinforce good behaviors, empower emotional control, educate on problem solving skills and social skills training. Effective parenting skills is crucial, and consistent supports from school and family are also important. Teaching strategies such as clear instructions, smalls steps for tasks with breaks, are usually effective. Positive reinforcements and avoiding environmental distractions can help reduce inattention symptoms. Medication for this age group might be consider for individual case, usually reserved for those with disruptive symptoms that cannot be effectively managed by behavioral therapy, since there are limited data for effectiveness and safety for children below age of 6 years.

There are 2 main groups of medication for ADHD: stimulants and non-stimulants. Stimulants are the first line treatment, which increase the level of dopamine in our brain, causing improved attention. Many studies had shown that around 75% of patients reported improved attention and reduced hyperactivity or impulsive symptoms with treatment. Some of the stimulants have long lasting effects while others are short lasting. Doctors will prescribe the medication according to child’s needs.

Common side effects of stimulants include poor appetite, difficulty in falling asleep or staying asleep, stomach pain, nausea, vomiting, diarrhoea, weight loss, headache, nervousness and irritability etc. These side effects are usually mild and short lasting and can be improved with adjustment of dosage.

Another group of medication is non-stimulants, which usually used as second line treatment for those without improvement of symptoms or experience significant side effects after taking stimulants.

What shall parents do if suspected their child has ADHD?

If parents worry their child has ADHD, they can bring their child to seek opinion and arrange appropriate assessment by paediatrician or psychiatrist. For those diagnosed ADHD, appropriate management including behavioural therapy will be advised and medication will be prescribed if indicated. Preschool children who also diagnosed with other co-existing developmental conditions such as dyslexia, developmental delay can be referred to Social Welfare Department for Preschool Rehabilitation Services, which includes Early Educational Training Centre (EETC), Integrated Programme in Kindergarten-cum-Child Care Centre (ICCC), On-site Pre-school Rehabilitation Services(OPRS) or Special Child Care Centre( SCCC).

Education Bureau provides support for school age children with special educational needs (SEN).

Seeking professional advice early and appropriate intervention promptly usually can get a better outcome. Children whose symptoms inadequately managed in childhood could persistently suffer during adulthood. If parents have doubt, they should seek advice from their doctors early.


The cause of ADHD is not fully understood yet, but it is generally believed to be related to genetics. The disease runs in family, with a higher prevalence in boys.

bottom of page