Attention Deficit Hyperactivity Disorder (ADHD or ADD)

ADHD is the most commonly studied and diagnosed psychiatric disorder in children, affecting about 3 to 5 percent of children globally and diagnosed in about 2 to 16 percent of school aged children. It is a chronic disorder with 30 to 50 percent of those individuals diagnosed in childhood continuing to have symptoms into adulthood. Adolescents and adults with ADHD tend to develop coping mechanisms to compensate for some or all of their impairments. 

ADHD is diagnosed two to four times more frequently in boys than in girls, though studies suggest this discrepancy may be partially due to subjective bias of referring teachers. ADHD management usually involves some combination of medications, behaviour modifications, lifestyle changes, and counselling. Its symptoms can be difficult to differentiate from other disorders, increasing the likelihood that the diagnosis of ADHD will be missed. 

ADHD and its diagnosis and treatment have been considered controversial since the 1970s. The controversies have involved clinicians, teachers, policymakers, parents and the media. Topics include the actuality of the disorder, its causes, and the use of stimulant medications in its treatment. Most healthcare providers accept that ADHD is a genuine disorder with debate in the scientific community centering mainly around how it is diagnosed and treated.

Hyperactivity is commonly seen in ADHD. Inattention, hyperactivity, and impulsivity are the key behaviours of ADHD. The symptoms of ADHD are especially difficult to define because it is hard to draw the line at where normal levels of inattention, hyperactivity, and impulsivity end and clinically significant levels requiring intervention begin. To be diagnosed with ADHD, symptoms must be observed in two different settings for six months or more and to a degree that is greater than other children of the same age. 

The symptom categories of ADHD in children yield three potential classifications of ADHD—predominantly inattentive type, predominantly hyperactive-impulsive type, or combined type if criteria for both subtypes are met. 

Predominantly inattentive type symptoms may include: 

• Be easily distracted, miss details, forget things, and frequently switch from one activity to another 
• Have difficulty maintaining focus on one task 
• Become bored with a task after only a few minutes, unless doing something enjoyable 
• Have difficulty focusing attention on organising and completing a task or learning something new or trouble completing or turning in homework assignments, often losing things (e.g., pencils, toys, assignments) needed to complete tasks or activities 
• Not seem to listen when spoken to 
• Daydream, become easily confused, and move slowly 
• Have difficulty processing information as quickly and accurately as others 
• Struggle to follow instructions 

Predominantly hyperactive-impulsive type symptoms may include: 

• Fidget and squirm in their seats 
• Talk nonstop 
• Dash around, touching or playing with anything and everything in sight 
• Have trouble sitting still during dinner, school, and story time 
• Be constantly in motion 
• Have difficulty doing quiet tasks or activities. 

and also, these manifestations primarily of impulsivity: 

• Be very impatient 
• Blurt out inappropriate comments, show their emotions without restraint, and act without regard for consequences 
• Have difficulty waiting for things they want or waiting their turns in games 

Most people exhibit some of these behaviours, but not to the degree where such behaviours significantly interfere with a person’s work, relationships, or studies—and in the absence of significant interference or impairment, a diagnosis of ADHD is normally not appropriate. The core impairments are consistent even in different cultural contexts. 

Symptoms may persist into adulthood for up to half of children diagnosed with ADHD. This rate is difficult to estimate, as there are no official diagnostic criteria for ADHD in adults. ADHD in adults remains a clinical diagnosis. The signs and symptoms may differ from those during childhood and adolescence due to the adaptive processes and avoidance mechanisms learned during the process of socialisation. 

A 2009 study found that children with ADHD move around a lot because it helps them stay alert enough to complete challenging tasks. 

Inattention and “hyperactive” behaviour are not the only problems in children with ADHD. ADHD exists alone in only about one-third of the children diagnosed with it. Such combinations can greatly complicate diagnosis and treatment. Many co-existing conditions require other courses of treatment and should be diagnosed separately instead of being grouped in the ADHD diagnosis. 

Anxiety and depression are some of the disorders which can accompany ADHD. Academic studies and research in private practice suggest that depression in ADHD appears to be increasingly prevalent in children as they get older, with a higher rate of increase in girls than in boys, and to vary in prevalence with the subtype of ADHD. Where a mood disorder complicates ADHD, it would be prudent to treat the mood disorder first, but parents of children who have ADHD often wish to have the ADHD treated first, because the response to treatment is quicker. 

Medical conditions that must be excluded include hypothyroidism, anaemia, lead poisoning, chronic illness, hearing or vision impairment, substance abuse, medication side effects, sleep impairment and child abuse, and cluttering (tachyphemia) among others. 

The relationship between ADHD and sleep is complex, as with other psychological and neurological issues. In addition to clinical observations, there is substantial empirical evidence from a neuroanatomic standpoint to suggest that there is considerable overlap in the central nervous system centres that regulate sleep and those that regulate attention/arousal. Primary sleep disorders play a role in the clinical presentation of symptoms of inattention and behavioural dysregulation. There are multilevel and bidirectional relationships among sleep, neurobehavioral functioning and the clinical syndrome of ADHD. 

Behavioural manifestations of sleepiness in children range from the classic ones (yawning, rubbing eyes), to externalising behaviours (impulsivity, hyperactivity, aggressiveness), to mood lability and inattentiveness. Many sleep disorders are important causes of symptoms which may overlap with the cardinal symptoms of ADHD; children with ADHD should be regularly and systematically assessed for sleep problems. 

As part of the diagnostic process for ADHD, the health care professional must determine whether there are any other conditions affecting the individual. Often, the symptoms of ADHD may overlap with other disorders. The challenge for the professional is to figure out whether a symptom belongs to ADHD, to a different disorder or to both disorders at the same time.