Contents
Background
ADHD is a neurodevelopmental disorder that begins in childhood, and is formed of the following core features:
1. Inattention:
- difficulty finishing tasks
- difficulty focussing on one task
- forgetting or misplacing things
- not paying attention to details
- being easily distracted and constantly ‘daydreaming’
- difficulty following multi-step instructions
- struggling to concentrate
2. Impulsivity and hyperactivity:
In younger children:
- fidgeting excessively
- running around and climbing furniture
- being unable to wait their turn
In school-age children/adolescents:
- interrupting others and talking excessively
- displaying a lack of consideration of risks- e.g. dangerous driving
- children and adolescents may seem like they are constantly “on the go”, either in a physical sense or when they are thinking/talking/planning
Some individuals may have a predominantly ‘inattentive’ subtype of ADHD, or predominantly ‘impulsivity-hyperactivity’ symptoms. ‘Hyperkinetic disorder’ is a term previously used in ICD-10 but has now been replaced by ADHD.
People with ADHD may have co-existing psychiatric and physical conditions including conduct disorder, oppositional defiant disorder, mood disorders, anxiety disorders, autism spectrum disorders, substance-use disorders, sleep disorders, epilepsy, and movement disorders.
Aetiology
Various theories have been proposed concerning the aetiology of ADHD, which are described below:
- Genetics: twin studies demonstrate a high heritability rate for ADHD
- Neurochemistry: possible dysfunction of neurotransmitters e.g. noradrenaline and dopamine release, demonstrated by a response to stimulants
- Neuroimaging: studies using functional MRI studies and neuroimaging have found some differences in brain structure and activity in parts of the brain including a reduction in basal ganglia grey matter
- Neuropsychology: executive dysfunction may arise from dysfunctional frontal-subcortical circuitry
- The risk of getting ADHD is likely increased by a combination of genetic and environment factors; the risk is most strongly linked to low birth weight and smoking during pregnancy.
Epidemiology
- The prevalence of ADHD in children is estimated to be around 2-7% globally, with a male: female prevalence of 2-5:1.
- Many individuals may have some ongoing symptoms in adulthood, especially symptoms relating to inattention, however symptoms relating to impulsivity and hyperactivity may recede over time.
Diagnosis
For a diagnosis of ADHD, symptoms usually (as per ICD-11):
-start before 12 years old (and are ‘age-inappropriate’)
-are present for >6 months (persistent)
-are present in more than one location (pervasive), for example in home and school
-cause ‘at least moderate’ impairment to social/academic/psychological functioning
-are not due to another mental disorder
-are not secondary to substances/withdrawal- e.g. cocaine use
Assessment
A comprehensive assessment of ADHD is composed of multiple components. A diagnosis can only be confirmed by a specialist psychiatrist, psychologist, or paediatrician.
If children present to primary care with ADHD symptoms, physicians should consider the wider impact of symptoms, for example children’s functioning at school, ability to maintain friendships and relationships, involvement with the police, and drug and alcohol use. Assessment should also include assessing parents’ or carers’ mental health and coping skills.
- History
an initial history of individuals with ADHD should include:
-collateral history from parents
-collateral history from school- including interactions with peers, academic abilities
-past psychiatric history- ODD/conduct disorders/mood disorders
-family history- of ADHD or other psychiatric illnesses
-developmental history- birth history, pregnancy, development
-past medical history- e.g. history of central nervous system infections
-social history- family interactions, peer relationships, forensic involvement, substance use
-risk- ability to avoid dangers and reduce risk, e.g. reckless driving, reduced contraceptive use
- Mental State Examination- note that individuals’ behaviour may be different during a consultation to behaviour at home/school.
- Assessment tools: the ‘Conners’ Rating Scale’ is an integral part of the assessment of patients presenting with possible ADHD and can help identify behavioural symptoms of ADHD.
- Neuropsychological assessment: not necessary for ADHD diagnosis but may be used to identify comorbidities. Individuals with ADHD may demonstrate difficulties in executive functioning and memory on neuropsychological testing (which assesses various brain functions- for example memory/concentration/attention/language skills).
Management
Management of ADHD involves holistic treatments to address difficulties in functioning at school and in the home environment. The general principles of management are outlined below, and should encompass psychological, social and academic/occupational needs.
- Psychoeducation for parents and families is key in ensuring a good understanding of the condition. This may also involve thinking about the ‘positive’ impacts of the diagnosis including individual strengths. Provide reassurance that ADHD is not caused by ‘bad parenting’ and challenge stigma.
- Signpost to parental support groups/organisations for peer support.
- Provide support for parents in terms of managing challenging behaviours, reinforcing positive behaviour, providing structure and boundaries like ‘time-outs’. Consider referring parents to ADHD-specific group parent-training programmes.
- Involve schools and universities to ensure adequate educational support.
- Behavioural interventions, including CBT, to manage social skills, impulsivity, dealing with feelings.
- Medication (only for >5-year-olds): discuss benefits and side effects, explore compliance.
Medication considerations and cautions
If excessive weight loss: encourage additional snacks, high-calorie nutritious foods, consider a treatment break.
If height is affected: consider a break in treatment during school holidays.
If sustained tachycardia/ hypertension: reduce dose and refer to a specialist.
As well as stimulant medications, medications such as clonidine and guanfacine (alpha-2-adrenergic agonists) may be used to manage sleep issues and challenging behaviours.
Be mindful of medication misuse for weight loss or concentration benefits, and illicit purchase of medications over the internet.
Controversies and grey areas
- There is widespread media interest in the ‘overdiagnosis’ and ‘overtreatment’ of ADHD. A review by Kazda et al. attributed this to factors such as: increasing awareness of the condition, changing diagnostic criteria, and ‘medicalisation’ of ‘normal’ behaviour in children that may be young for their school year. Furthermore, long waiting lists for ADHD assessment in the NHS has led to many undergoing private assessments. It is worth considering the preconceptions that patients, caregivers, and healthcare professionals themselves may have about ADHD as a condition and the pharmaceutical management.
- Although there are theoretical links between hyperactivity and synthetic food additives in the literature, NICE guidelines do NOT recommend that healthcare professionals specifically advise parents to cut out artificial additives or colourings from children’s diet to help with ADHD symptoms.
There are various theories explaining the differences in ADHD prevalence in girls versus boys. Some of these theories are summarised below:
-females may have more symptoms of the ‘inattentive’ subtype of ADHD, which may be less overt than ‘hyperactivity’ symptoms and therefore more difficult to diagnose
-females may appear to have less severe symptoms, or have fewer disruptive behaviours
-females may be better at masking symptoms or may appear to ‘function’ better
-ADHD rating scales may disadvantage females with ADHD
-people may have gender biases and misconceptions about the ‘typical’ ADHD patient
Key take-home points
-ADHD is a neurodevelopmental condition that is characterised by symptoms of hyperactivity and/or impulsivity-inattention.
-Symptoms usually start before the age of 12 years old, persist for over 6 months, occur in more than one location, and cause at least moderate impairment to functioning.
-Assessment includes: a comprehensive history including a collateral history, examination including an MSE, assessment with ADHD rating-scales, and may include neuropsychological testing.
-Alongside psychoeducation, behavioural interventions, and parental support, medications such as methylphenidate may be trialled in children >5 years old.
References
NICE GUIDELINES – ADHD: DIAGNOSIS AND MANAGEMENT, https://www.nice.org.uk/guidance/ng87
NICE CKS, https://cks.nice.org.uk/topics/attention-deficit-hyperactivity-disorder/
ICD-11
OXFORD HANDBOOK OF CLINICAL SPECIALITIES, Baldwin A.
PREVALENCE: HTTPS://WWW.THELANCET.COM/JOURNALS/LANPSY/ARTICLE/PIIS2215-0366(17)30167-0/FULLTEXT#%20
OVERDIAGNOSIS AND CONTROVERSIES: HTTPS://JAMANETWORK.COM/JOURNALS/JAMANETWORKOPEN/FULLARTICLE/2778451
HTTPS://WWW.BBC.CO.UK/NEWS/HEALTH-65534448
FOOD ADDITIVES AND ADHD: HTTPS://PUBMED.NCBI.NLM.NIH.GOV/35484553/
ADHD IN FEMALES: HTTPS://WWW.NCBI.NLM.NIH.GOV/PMC/ARTICLES/PMC7422602/
Written by:
Dr Anya Baig (FY2)
Reviewed by:
Dr Aleksandra Szczap (ST6 Child and Adolescent Psychiatry)
