Neurodevelopmental Disorders II: ADHD and Disruptive Behaviour

MKU MBChB Year 4 · Junior Clerkship · Week 7 · Clinical revision notes

Start here: ADHD explained from zero

Before memorising the medical words, understand the everyday examples.

What is ADHD?

Imagine a teacher asks a child to sit down, listen and finish classwork. The child repeatedly gets distracted, keeps moving, interrupts and leaves work unfinished. Similar problems happen at home and affect daily life.

ADHD means Attention-Deficit/Hyperactivity Disorder. It describes a persistent pattern of difficulty with attention and/or excessive activity and acting without pausing to think. It is not proof that a child is lazy, unintelligent or deliberately naughty.

The three words you must understand

1. Inattention = difficulty focusing

Example: the child starts homework, notices something else, forgets the instruction and leaves the work unfinished.

Think: “I find it hard to keep my mind on this task.”

2. Hyperactivity = excessive movement or activity

Example: the child fidgets, keeps getting out of their seat or struggles to play quietly when expected.

Think: “My body keeps moving.”

3. Impulsivity = acting before pausing to think

Example: the child shouts an answer before the teacher finishes the question or repeatedly interrupts others.

Think: “I act before I stop to think.”

Not every child with ADHD has all three kinds of difficulty. Some mainly struggle with attention; others mainly show hyperactivity and impulsivity; some have both groups.

Does every active or distracted child have ADHD?

No. Children can be active, tired, worried or distracted sometimes. Clinicians look for a persistent pattern that is not expected for the child's developmental level and that causes real problems in daily life.

For a child, remember these checks:

• Symptoms generally persist for at least 6 months.
• Several symptoms were present before age 12.
• Symptoms occur in at least two settings, such as home and school.
• Symptoms clearly affect learning, relationships or daily functioning.
• The clinician considers other explanations, including poor sleep, anxiety, learning difficulties, hearing problems or stressful experiences.

A teacher's report or checklist can help, but neither alone confirms ADHD.

Quick understanding check

A 9-year-old repeatedly answers before the teacher finishes asking a question. Which word describes this behaviour?

• Inattention: difficulty keeping focus.
• Hyperactivity: excessive movement or activity.
• Impulsivity: acting or speaking before pausing to think.

Answer: Impulsivity. The child is answering before stopping to think.

Start here: the big picture

ADHD mainly involves persistent problems with attention and/or hyperactivity-impulsivity that are greater than expected for the person's developmental level and interfere with functioning.

Disruptive behaviour disorders involve persistent patterns of behaviour that challenge rules, relationships or the rights of others. Two key diagnoses are oppositional defiant disorder (ODD) and conduct disorder (CD).

A child being active, stubborn or naughty occasionally does not automatically have a psychiatric disorder. Assess persistence, severity, developmental stage, impairment, context and alternative explanations.

1. Attention-deficit/hyperactivity disorder (ADHD)

Definition and core symptom groups

ADHD is a neurodevelopmental disorder with developmentally inappropriate and impairing symptoms in one or both groups:

A. Inattention

• Often misses details or makes careless mistakes.
• Struggles to sustain attention in play, lessons or tasks.
• Seems not to listen when spoken to directly.
• Does not finish instructions or tasks; may shift to another activity.
• Has difficulty organising tasks and activities.
• Avoids tasks requiring sustained mental effort.
• Frequently loses necessary items.
• Is easily distracted by unrelated stimuli.
• Is forgetful in everyday activities.

B. Hyperactivity and impulsivity

• Fidgets, taps hands/feet or squirms.
• Leaves the seat when remaining seated is expected.
• Runs or climbs in inappropriate situations; in older people this may feel like restlessness.
• Has difficulty playing or doing leisure activities quietly.
• Seems constantly “on the go.”
• Talks excessively.
• Answers before a question is completed.
• Has difficulty waiting their turn.
• Interrupts or intrudes on others.

Memory aid: Inattention = difficulty directing and sustaining focus; hyperactivity = excessive activity; impulsivity = acting before pausing to think.

Diagnostic essentials (DSM-5-TR framework)

For an exam, remember 6–6–12–2–impairment:

• 6 symptoms in a symptom group for at least 6 months for children up to age 16; for age 17 and older, at least 5 symptoms.
• Several symptoms were present before age 12.
• Symptoms occur in 2 or more settings (e.g. home and school).
• There is clear evidence that symptoms interfere with or reduce the quality of social, academic or occupational functioning.
• Symptoms are not better explained by another mental disorder or occurring only during psychosis.

A clinician must establish the full pattern; a checklist or teacher report alone is not enough. Symptoms should be inconsistent with developmental level and not simply reflect ordinary age-appropriate activity.

Presentations

• Predominantly inattentive presentation: inattention criteria are met, but hyperactivity-impulsivity criteria are not.
• Predominantly hyperactive/impulsive presentation: hyperactivity-impulsivity criteria are met, but inattention criteria are not.
• Combined presentation: criteria are met for both groups.

Presentation can change over time. ADHD can persist into adolescence and adulthood.

How it may present in clinic or school

A child may repeatedly lose books, forget instructions, leave their seat, interrupt others, fail to complete work despite understanding it, or perform inconsistently. Consequences can include poor school progress, family conflict, peer difficulties, accidents and low self-esteem.

Do not assume a child with ADHD lacks intelligence or is deliberately misbehaving. Ask what happens before and after the behaviour, and whether the child can manage better with structure or support.

2. Assessment of suspected ADHD

1. Clarify the concern: examples, onset, duration, frequency, severity and functional impact.
2. Take a developmental and school history: learning, language, milestones, attendance, classroom behaviour and academic progress.
3. Obtain information from more than one setting: caregiver and teacher reports are useful; compare settings rather than relying on one person's opinion.
4. Assess functioning and context: family stress, sleep routine, trauma, bullying, school environment, language of instruction and access to learning support.
5. Screen for coexisting conditions: learning/language disorders, autism, anxiety, depression, oppositional behaviour, conduct problems, tics and substance use in adolescents.
6. Consider physical and medical contributors: hearing or visual impairment, sleep disorders, seizures or other conditions suggested by the history; review medicines and relevant exposures.
7. Examination and investigations: perform a focused physical and developmental assessment. There is no single blood test, brain scan or routine laboratory test that diagnoses ADHD. Order tests only when clinically indicated.
8. Use rating scales as aids, not as the diagnosis: tools may support structured assessment, but clinical history, impairment and differential diagnosis remain essential.

Important differentials

• Normal developmental activity: behaviour is age-appropriate and does not cause persistent significant impairment.
• Sleep deprivation or sleep-disordered breathing: poor sleep can cause inattention and irritability.
• Anxiety or depression: concentration may be impaired by worry, low mood or loss of interest.
• Trauma, bullying or major stress: behaviour may be linked to threat or context.
• Learning or language disorder: the child may avoid work they cannot understand or complete.
• Autism spectrum disorder: social-communication differences and restricted/repetitive behaviours; ADHD can coexist.
• Hearing or visual impairment: may look like not listening or not following instructions.
• Seizures or other medical conditions: consider when history or examination points to them.

3. Management of ADHD

Management is individualised and usually combines practical support with treatment matched to age, severity and impairment.

Non-pharmacological support

• Explain ADHD in non-stigmatising language to the child and caregivers.
• Give clear, short instructions; ask the child to repeat them back.
• Break work into small steps and use predictable routines and visual reminders.
• Reduce avoidable distractions; allow planned movement breaks.
• Reinforce specific positive behaviours immediately and consistently.
• Work with teachers on seating, task length, feedback and reasonable learning adjustments.
• Support sleep routines, physical activity and family problem-solving.
• Offer evidence-based parent training/behavioural support when available.

Medication

Medication may be appropriate when ADHD is confirmed and symptoms cause significant impairment. Common options in guidelines include stimulants such as methylphenidate and non-stimulants such as atomoxetine; availability, approvals and protocols vary by setting.

Medication should be initiated and monitored by an appropriately trained clinician. Review benefit, appetite, sleep, growth, blood pressure, pulse, mood, adverse effects, adherence and relevant cardiac or psychiatric history. Do not self-medicate a child or borrow another person's medicine. Medication is not a substitute for school and family support.

4. Disruptive behaviour disorders

Oppositional defiant disorder (ODD)

ODD is a persistent pattern of angry/irritable mood, argumentative/defiant behaviour, or vindictiveness that is more frequent or severe than expected for developmental age and causes distress or impairment.

Examples include:

• Often losing temper or becoming easily annoyed.
• Frequently arguing with adults or authority figures.
• Actively refusing reasonable requests or rules.
• Deliberately annoying others or blaming others for mistakes.
• Being spiteful or vindictive.

Symptoms are generally assessed over at least 6 months, considering frequency, age and relationship context. For children younger than 5, the behaviour is typically present on most days; for those 5 and older, typically at least weekly, though frequency alone does not establish the diagnosis.

Key point: ODD does not by definition include the serious violation of other people's basic rights or major age-appropriate societal rules that characterises conduct disorder.

Conduct disorder (CD)

CD involves a repetitive and persistent pattern of behaviour in which the basic rights of others or major age-appropriate rules are violated.

The symptom groups include:

• Aggression toward people or animals: bullying, initiating fights, cruelty, using a weapon or forcing sexual activity.
• Destruction of property: deliberate fire-setting or other intentional serious destruction.
• Deceitfulness or theft: breaking into property, repeated lying to obtain goods or avoid obligations, stealing items of value.
• Serious rule violations: repeated staying out despite caregiver prohibitions, running away overnight or truancy beginning before age 13.

A single fight or isolated rule-breaking episode is not enough. Assess the pattern, duration, severity, context and safety of others. Ask about trauma, abuse, exploitation, peer influence, substance use, family stress and neurodevelopmental needs without assuming these automatically explain or excuse harm.

ODD versus conduct disorder

• ODD: defiance, argumentativeness, irritability and vindictiveness.
• CD: aggression, destruction, deceit/theft or serious rule violations.
• They may co-occur, and ADHD may also be present. These diagnoses are not labels for a “bad child”; they guide assessment and support.

5. Assessment and management of disruptive behaviour

What to ask

• What exactly happened? How often, how long, and in which settings?
• When did the pattern begin? Is it escalating?
• What tends to happen before and after the behaviour?
• Are there injuries, threats, weapons, cruelty, fire-setting, exploitation or risk to a vulnerable person?
• How are school, peers, caregivers and daily functioning affected?
• Ask about developmental history, learning difficulties, ADHD/ASD, mood, anxiety, trauma, substance use, sleep and family stress.
• Obtain collateral information from caregivers and school where appropriate, while considering safety, confidentiality and the child's age.

Management principles

• Safety first: assess immediate risk to the child and others; follow safeguarding and local emergency procedures when there is imminent danger.
• Build a collaborative, non-shaming plan with the child and caregivers.
• Use evidence-based parent-management training and behavioural interventions when available.
• Coordinate school support, predictable boundaries, consistent reinforcement and help with learning needs.
• Treat coexisting ADHD, mood/anxiety disorders, trauma-related problems or substance use when present.
• Consider family, social and child-protection services when indicated.
• Medication is not a routine treatment for ODD or CD themselves; it may be used by a qualified clinician for a diagnosed coexisting condition or a specific severe target symptom, with clear monitoring.

6. Clinical case: apply the framework

A 9-year-old is referred because they leave their seat, interrupt lessons, lose books and rarely finish classwork. The teacher reports these difficulties for 8 months. The caregiver reports similar problems at home. School performance is declining.

Approach

1. The symptoms suggest possible ADHD, but do not diagnose from this description alone.
2. Confirm symptom number, developmental appropriateness, onset before age 12, duration, presence in multiple settings and functional impairment.
3. Ask about sleep, learning, language, hearing/vision, mood/anxiety, trauma and medical history.
4. Obtain caregiver and teacher information; assess coexisting conditions.
5. Agree on school/family supports and arrange an appropriate clinical assessment and treatment plan.

Variation: If the child mainly argues, loses their temper and refuses requests, assess the pattern for ODD. If there is repeated aggression, serious destruction, theft or major rule violations, assess for CD and prioritise safety. Do not infer either diagnosis from one incident.

7. Quick exam checks

1. A 10-year-old has inattention for 2 months, only at school, after a recent family crisis. Is ADHD established?
No. The duration and cross-setting requirements are not met, and stress-related or other explanations need assessment.

2. What does “symptoms in two or more settings” mean?
The pattern occurs in at least two settings, such as home and school; a problem reported by only one observer needs further exploration.

3. Which pattern best describes ODD?
Persistent irritability, arguing/defiance and/or vindictiveness—not merely occasional disobedience.

4. Which pattern raises concern for CD?
A persistent pattern involving aggression, destruction, deceit/theft or serious rule violations.

5. Is there a blood test that confirms ADHD?
No. Diagnosis is clinical and based on developmental history, symptoms, impairment, information across settings and differential assessment.

6. What is the first priority when a child reports serious violence or cruelty?
Assess immediate safety and safeguarding needs, then arrange an appropriate comprehensive assessment.

Take-home points

• ADHD is about persistent, impairing inattention and/or hyperactivity-impulsivity—not simply being energetic.
• Use 6 months, before age 12, two or more settings, and impairment as the core diagnostic memory aid.
• ODD centres on defiance/irritability/vindictiveness; CD involves serious violations of rights or major rules.
• Assess the whole child and context, screen for coexisting conditions, and avoid stigmatising labels.
• Combine appropriate clinical treatment with family, school and psychosocial support.

References for further study

• American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), 2022.
• National Institute for Health and Care Excellence (NICE). Attention deficit hyperactivity disorder: diagnosis and management (NG87).
• World Health Organization. ICD-11: Clinical descriptions and diagnostic requirements for mental, behavioural and neurodevelopmental disorders.