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.
Signs and symptoms
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:
Predominantly hyperactive-impulsive type symptoms may include:
and also these manifestations primarily of impulsivity:
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 1/3 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.
The specific causes of ADHD are not known. There are, however, a number of factors that may contribute to, or exacerbate ADHD. They include genetics, diet and the social and physical environments.
To make the diagnosis of ADHD, a number of other possible medical and psychological conditions must be excluded.
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.
As with other psychological and neurological issues, the relationship between ADHD and sleep is complex. 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 externalizing 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.
Methods of treatment often involve some combination of behaviour modification, life-style changes, counselling, and medication. A 2005 study found that medical management and behavioural treatment is the most effective ADHD management strategy, followed by medication alone, and then behavioural treatment. While medication has been shown to improve behaviour when taken over the short term, they have not been shown to alter long term outcomes. Medications have at least some effect in about 80% of people.
The evidence is strong for the effectiveness of behavioural treatments in ADHD. It is recommended first line in those who have mild symptoms and in preschool aged children. Psychological therapies used include psych educational input, behaviour therapy, cognitive behavioural therapy (CBT), interpersonal psychotherapy (IPT), family therapy, school-based interventions, social skills training and parent management training.
Methylphenidate (Ritalin) 10 mg tablets
Stimulant medication is the medical treatment of choice. There are a number of non-stimulant medications, such as atomoxetine, that may be used as alternatives. There are no good studies of comparative effectiveness between various medications, and there is a lack of evidence on their effects on academic performance and social behaviours. While stimulants and atomoxetine are generally safe, there are side effects and contraindications to their use.