ADHD & Oppositional Defiant Disorder
Written 12th April 2020 - Last Update 27th September 2026
ADHD & Oppositional Defiant Disorder
ADHD affects attention, hyperactivity and impulse control, and can impair learning, social skills and family functioning. Highly heritable; one of the most common childhood conditions; underdiagnosed — around 1 in 4 affected children may go undiagnosed. Affects 6–10% of Australian children, more common in boys. See also behavioural problems in childhood and tic disorders (comorbidity).
Presentation
Inattention: rushes work, skips steps, makes careless errors, misses social cues from rushing, poor listening/“selective hearing”, mind elsewhere, single-minded, starts but doesn’t finish tasks, needs single-step instructions.
Organisation/persistence: can’t prioritise, poor time management, messy, over-commits socially, seen as defiant/lazy.
Distractibility: daydreaming, off-topic thoughts, doodling, sensory behaviours, disjointed storytelling; forgets chores/tasks.
Hyperactivity/impulsivity: always “on the go”, rushes everything, “class clown”, fidgets, appears self-centred, can’t wait their turn, talks incessantly.
DSM-5 criteria
Three presentations — predominantly hyperactive/impulsive, predominantly inattentive (most common), and mixed. Symptoms must be present before age 12 and often persist into adulthood.
Hyperactive/impulsive (≥6 of 9): fidgets/squirms; leaves seat when expected to remain seated; runs/climbs excessively (or subjective restlessness in older patients); can’t play quietly; “on the go”; talks excessively; blurts answers before questions finish; difficulty awaiting turn; interrupts/intrudes on others.
Inattentive (≥6 of 9): careless mistakes/misses detail; difficulty sustaining attention; doesn’t seem to listen when spoken to; doesn’t follow through/finish tasks (not from defiance or misunderstanding); difficulty organising tasks; avoids sustained-mental-effort tasks; loses things; easily distracted; forgetful in daily activities.
Mixed — meets both sets of criteria.
Diagnosis: symptoms must be evident in more than one environment (e.g. home and school) and are usually raised by parents, sometimes prompted by a teacher/early-childhood-worker query; often becomes apparent as academic demands rise (school entry, or around age 7–8). Diagnosis should only be made by an appropriately experienced psychologist, paediatrician or child psychiatrist, using information from parents, teachers and other key adults — functional impairment across ≥2 settings, not symptom counts, is the key to diagnosis.
Who to screen
ADHD prevalence is higher than the general population in several groups worth opportunistic screening: children in out-of-home care or diagnosed with ODD/conduct disorder; children and adolescents with anxiety disorders, epilepsy, or a substance use history; and people of any age with other neurodevelopmental disorders (autism, intellectual disability, tic or learning disorders), a close family member with ADHD, preterm birth, low birth weight, or a sleep disorder. ADHD can be under-recognised in girls and women — they are less likely to be referred for assessment, more likely to have undiagnosed ADHD, and more likely to be misdiagnosed with an anxiety or depressive disorder instead. Universal population-level screening (e.g. in schools) is not recommended; targeted screening within these higher-risk groups is.
Initial assessment
Screen: hearing, vision, sleep (ask specifically about OSA — if snoring >2 nights/week, consider lateral airway X-ray for adenoids, or a sleep study). Check iron, B12, TSH, coeliac serology. Trial melatonin for sleep if needed. Also consider other conditions that can mimic or exacerbate ADHD symptoms (hearing/vision impairment, thyroid disease, anaemia) and medications with psychomotor side effects — cognitive dulling from mood stabilisers, or psychomotor activation from decongestants, asthma medication, or non-prescribed stimulants like caffeine.
Assessment tools: SNAP-IV, Vanderbilt — get both parents and teachers to complete these. An Adult ADHD Self-Report Scale (ASRS v1.1) — an 18-item WHO-developed tool (6-item short form often used first) — is the standard brief screen for adult ADHD in general practice, useful for triaging who needs full assessment (a screen, not a diagnostic instrument on its own).
Management
Multimodal — pharmacological and non-pharmacological treatment concurrently.
Behavioural strategies (offer to all children, even sub-threshold)
| Domain | Strategies |
|---|---|
| Verbal instructions | Keep brief and clear; say the child’s name or tap their shoulder first; keep eye contact |
| Written work | Highlighters; asterisks/CAPS/bold for emphasis |
| Learning | One-on-one teaching where possible; class “buddies”; hands-on activities; do the hardest work when concentration is best (usually morning); checklists; sit front-and-centre, away from friends; clutter-free, distraction-free homework space; organised bag/diary/desk/locker; a regular homework time |
| Reduce overactivity/fatigue | Regular rest breaks; physically active breaks (e.g. delivering notes) |
| Structure | Fixed routine; predictable activities; visible schedules/rules (home + school, multiple places); advance warning of changes; countdowns (e.g. 5-min warning); minimal choices |
| Self-esteem | Achievable goals; acknowledge achievements and effort (written + verbal); ensure participation and positive feedback; address specific learning difficulties promptly |
| Social skills | Small groups over large; reward appropriate social behaviour; teach problem-solving for provocation; supervised socialisation (sport, Scouts); discuss consequences of actions; visual prompts (STOP, THINK, DO) |
| Home–school communication | A formal channel (diary, online portal), used regularly for both positive and negative behaviours |
Parenting education/support, improved understanding of ADHD, and psychologist-led behavioural strategies (better than medication in children <6) are all part of the non-pharmacological arm. Schools should provide an individualised education plan (IEP) for diagnosed children. Cognitive-behavioural interventions should be offered to adolescents and adults with ADHD, and could be offered to children — younger children benefit most from a foundation of emotional literacy and problem-solving, older children and adults from more sophisticated behavioural/cognitive-restructuring techniques; when delivered to children, a parent should be involved alongside. ADHD coaching (individual or group, via an appropriately credentialled coach or allied health professional) could also be considered for adolescents and adults. Lifestyle guidance — asking about and addressing sleep, diet and physical activity — should be offered to everyone with ADHD, alongside these other non-pharmacological options.
Sleep difficulties in ADHD are common and range from insomnia to delayed sleep phase and irregular patterns. Eating disorders, particularly binge eating disorder, are more common in ADHD than in the general population. Adults with ADHD are more likely than the general population to report adverse childhood experiences and exposure to trauma, so a trauma load should be considered in their care.
For adults, useful strategies include a regular sleep–wake routine (watch for “revenge bedtime procrastination”), movement breaks or an exercise buddy, and meal planning with shared lists or visual planners. Energy budgeting helps individuals recognise fluctuations in their internal resources and respond with intentional regulation strategies rather than binge eating, screens or gambling. CBT strategies for executive function include breaking tasks into smaller steps, the Pomodoro Technique and body doubling. DBT skills (distress tolerance, emotion regulation) help emotional dysregulation and rejection sensitivity. For children, GPs can write letters to school outlining the diagnosis and supports to underpin an individual learning plan.
GPs can support access to non-pharmacological care. Where ADHD is the main issue, a mental health treatment plan gives access to Medicare-funded psychological treatment (up to 10 sessions per year). Where ADHD causes chronic functional impairment, a GP chronic condition management plan (GPCCMP) supports coordinated care with up to five allied health sessions per year.
Medication
First-line: methylphenidate, dexamfetamine, or lisdexamfetamine, used within the multimodal approach where ADHD causes significant impairment. Atomoxetine, guanfacine or clonidine are alternatives if stimulants are contraindicated, not tolerated, or ineffective — parent/family training should be offered alongside medication for children (more intensive programs where ODD or conduct disorder co-occurs).
- Methylphenidate (Ritalin, short-acting, 3–4 hrs) — start with this immediate-release form; slow-release options: Ritalin LA (6–8 hrs), Concerta (10 hrs).
- Dexamfetamine, lisdexamfetamine (Vyvanse — long-acting), atomoxetine (Strattera) are other options.
- Generally avoid stimulants under age 4. Who may initiate or continue a stimulant now depends on the state or territory and the GP’s training — see Regulation, PBS and medicolegal below.
- Mechanism: increases synaptic noradrenaline/dopamine.
- Common side effects: reduced appetite, poor weight gain.
- Uncommon: headache/dizziness, stomach aches, insomnia, irritability/ emotional lability.
- Slight growth stunting (rarely clinically significant); slight increase in heart rate/BP (not usually an issue without underlying cardiac disease). An ECG is not routinely needed before starting stimulants, atomoxetine or guanfacine, unless specific cardiac risk features are present.
- ~1–2% of Australian children are prescribed stimulants at some stage; ~8/10 show significant improvement in concentration, impulse control and overactivity. Public/media concern about addiction is largely unfounded, though side effects (mostly non-serious) do occur.
- Fish oil: sometimes suggested, evidence for benefit is unclear.
Start at a low dose and titrate gradually, usually at 1–2 weekly intervals, guided by clinical response rather than a predetermined target dose. For stimulants, benefit can be judged relatively quickly, whereas non-stimulants typically need 4–12 weeks before full benefit can be assessed. If response to one stimulant is suboptimal, it is generally appropriate to trial the alternative stimulant class before moving to non-stimulants. Medication holidays are not recommended for the non-stimulants, which require continuous administration to maintain benefit. Current evidence from large population studies does not indicate an increased risk of serious cardiovascular events in individuals without known cardiac disease.
Choosing a first medication
Stimulants demonstrate the greatest effect sizes for core ADHD symptoms. Most patients will respond to at least one stimulant, although the optimal choice and dose cannot be predicted in advance. Frame the first prescription as a trial, and discuss possible medication diversion before starting.
| Stimulant (S8) | Duration (h) | Suggested max daily dose | Doses/day | Timing |
|---|---|---|---|---|
| Lisdexamfetamine (Vyvanse) | 10–13 | 70 mg | 1 | Before 9 am |
| Dexamfetamine | 4 | 40 mg | 2–3 | Last dose before 4 pm |
| Methylphenidate IR (Ritalin) | 4 | 60 mg | 2–3 | Last dose before 4 pm |
| Methylphenidate SR (Ritalin LA / Concerta) | 8 / 12 | 72 mg | 1 | Morning |
Atomoxetine is a common first choice when concentration and attention issues are the primary concern. Clonidine is considered more sedating and can cause hypotensive episodes; guanfacine is longer acting and may suit emotional regulation and impulsivity. Taper guanfacine (and sometimes clonidine) when stopping, to avoid rebound hypertension.
| Non-stimulant (S4) | Adult starting dose and titration | Consider if | Trial length |
|---|---|---|---|
| Atomoxetine | 40 mg daily; increase every 3 days to target 80 mg; max 100 mg | Stimulant intolerance, misuse/diversion concern, co-occurring anxiety | 4–8 weeks |
| Guanfacine | 1 mg at bedtime; review at 1 week; increase 1 mg weekly; max 7 mg | Emotional dysregulation, impulsivity, hyperarousal, sleep difficulty. Monitor BP and sedation | 4–8 weeks |
| Clonidine (off label) | 25–50 microgram; increase by 50 microgram every 3 days; max 300 microgram (1–2 doses/day) | Sleep-onset difficulty, hyperarousal, aggression. Monitor BP | 2–4 weeks |
Paediatric dosing: see the AADPA Prescribing Guide.
Short- vs long-acting stimulants
Neither is preferred. Short-acting forms are easier to titrate, their quick on/off effect helps confirm the diagnosis, side effects wear off sooner (with more rebound), and they are cheaper. But they need dosing at school or work. Efficacy of SA methylphenidate is currently required for PBS subsidy of long-acting forms.
Example paediatric protocol: dexamfetamine 5 mg or methylphenidate IR 10 mg tablets at breakfast and lunch.
| Weight | Week 1 | Week 2 | Week 3 | Week 4 |
|---|---|---|---|---|
| 20 kg | ¼ + ¼ | ½ + ½ | ¾ + ¾ | 1 + 1 |
| 30 kg | ½ + ½ | 1 + 1 | 1½ + 1 | 1½ + 1½ |
| 40+ kg | ½ + ½ | 1 + 1 | 1½ + 1½ | 2 + 2 |
At each review ask: is day-to-day function better, what difficulties remain, are side effects manageable, and does the duration of effect fit the day? Benefit is often noticed first by family or friends. If a dose increase does not improve function, some practitioners drop back to the lower dose. If cover wears off too early, add a single afternoon short-acting dose; low-dose evening clonidine may help poor sleep.
When it isn’t working
Before switching, check the dose is optimised, the duration of action fits, adherence is consistent and expectations are realistic. Also look for mood disorder, perimenopause/menopause, drug and alcohol use, poor sleep or skipped meals. Switching between stimulant classes typically involves ceasing one medication and initiating the alternative at a low dose, followed by re-titration. Once an effective IR methylphenidate dose is established, Ritalin LA can usually be dose-matched. There is no universally accepted dose equivalence between dexamfetamine and lisdexamfetamine — treat that switch as a new titration. Clonidine and guanfacine are commonly co-prescribed with stimulants. Escalate to a paediatrician or psychiatrist for diagnostic uncertainty, significant comorbidity or poor response.
Stimulant “holidays” can be used — mainly to protect appetite — though evidence of benefit is unclear. After stable dosing, doses can be skipped on days they aren’t needed.
Review
School and home progress; sleep; appetite; mood; BP/HR/weight/height (±SNAP scores); duration of medication cover (may need a short-acting top-up for evening activities). GP Shared Care arrangements are available through some regional programs.
Arrange frequent follow-up until medication is titrated and stabilised, then move to individualised chronic-disease-model monitoring — frequency depends on comorbidities, adverse effects, response and social supports. Encourage the person (or parent/carer) to keep their own record of adverse effects, and use a standard symptom/adverse-effect rating scale at each review. Everyone on ADHD medication should have height measured every 6 months (children/adolescents) and weight at 3 and 6 months after starting then 6-monthly, plotted on a growth chart; monitor heart rate and BP before and after each dose change and at least 6-monthly. If weight loss or poor weight gain is a concern, try dosing with or after food, extra high-calorie snacks early/late in the day, or a planned treatment break; a significant drop in height growth velocity may warrant a holiday-period treatment break or a change of medication. Watch for tics, seizures, sexual dysfunction, worsening mood/anxiety, and the risk of stimulant diversion, in addition to the usual adverse effects. Review medication at least annually, covering: benefit throughout the day, adverse effects, whether the dose is optimised, impact on education/employment/participation, and the person’s own preference for continuing, stopping or changing — trial periods off medication or at a reduced dose are reasonable when the overall balance of benefit and harm is unclear. Taper rather than stop abruptly for any medication known to cause discontinuation symptoms.
Regulation, PBS and medicolegal
ADHD stimulants are Schedule 8 (S8) medicines. The non-stimulants atomoxetine, guanfacine and clonidine are Schedule 4 medicines. Atomoxetine and guanfacine are TGA-approved for ADHD. Clonidine is off label for ADHD: document informed consent and the reason for unapproved use in the record. TGA-approved age ranges also matter — prescribing outside them is off label too (e.g. dexamfetamine 3–17 years, IR methylphenidate 6–17, lisdexamfetamine 6–55, Concerta and atomoxetine 6–65).
State rules (as at June 2026 — changing fast, check before prescribing). State laws differ substantially — Queensland is the least restrictive, while Victoria and the NT have the most onerous requirements.
| State/territory | GP stimulant prescribing |
|---|---|
| NSW | Since 1 September 2025, GPs may apply for a continuation prescriber authority number: endorsed training, >12-month relationship, patient ≥6 y, stable on specialist-started treatment, not drug dependent, within dose caps; check SafeScript NSW. Otherwise co-management with a psychiatrist or paediatrician and an individual application. GP initiation after further training is being rolled out |
| Qld | Since 1 December 2025, no approval needed for anyone aged ≥4 y within maximum daily doses (dexamfetamine 40 mg, lisdexamfetamine 70 mg, methylphenidate 80 mg). No extra training or specialist co-management required |
| ACT | Trained GPs who notify the CHO can continue specialist-started treatment (≥6 y, stable); GP initiation planned later in 2026 |
| SA | From 28 Feb 2026, RACGP-trained GPs can diagnose and apply for initial authority |
| Tas | Trained GPs can diagnose and initiate |
| WA | Continue (not initiate) under shared care with the specialist, within dose limits and specialist review intervals |
| Vic | Permit per patient, usually needing specialist diagnosis/review; GP training program started June 2026 |
| NT | Approval per patient with specialist co-management; no changes proposed |
Since 1 September 2025, GPs may apply to the Ministry of Health for a continuation prescriber authority number in NSW. In Queensland, GPs do not need to apply for approval for anyone aged 4 years or older within set maximum daily doses. Checking real-time prescription monitoring is mandatory in the NT, Qld, SA, Tas, Vic and WA; in NSW and the ACT it’s mandatory only for GPs prescribing under the new trained-GP pathways.
PBS. Stimulants are Authority Required, with limits on dose, quantity, repeats and age at diagnosis. For all modified release forms, patients must have responded to immediate release forms without adverse reaction. For long-acting methylphenidate capsules and lisdexamfetamine started after age 18, the PBS needs a documented retrospective diagnosis: childhood-onset symptoms supported by an interview with, or evidence from, a parent, teacher, sibling or other third party. Under the PBS, guanfacine and atomoxetine cannot be initiated by GPs, but can be continued once a specialist has commenced PBS-subsidised treatment. For PBS subsidy, guanfacine and atomoxetine require an ADHD diagnosis before the age of 18 years.
Telehealth. Consider whether an online consultation is enough to verify identity, assess risks and justify the medication. Asynchronous questionnaire-based prescribing is discouraged by the Medical Board. Vic and WA require identity verification before any S8 prescription. Prescribing across state borders may need to meet both states’ rules — ask your MDO.
Medicolegal risks include repeat scripts without adequate review, not assessing response, side effects and function, and not reassessing ongoing need. Suspected forged or stolen S8 scripts may be disclosed to police under privacy law if unlawful activity is reasonably suspected.
Driving. ADHD and its stimulant treatment only require reporting to driver licensing authorities if they impair behaviour, cognition, insight or perception in a way that affects safe driving. Mandatory GP reporting applies only in SA and the NT (and heavy-vehicle licences in the ACT). Document stimulant use in any fitness-to-drive report.
Consent in children. First ask whether the child is Gillick competent — get a psychiatric opinion if relying on that to settle a parental dispute. SA law sets 16 years, or two doctors’ agreement under 16. Where parents disagree about a child’s ADHD treatment, Australian law presumes either parent can consent, unless parenting orders or suspected family violence say otherwise. File any parenting orders and seek MDO advice.
Oppositional defiant disorder (ODD)
An ongoing pattern of anger-driven disobedience and hostile/defiant behaviour toward authority figures, beyond normal childhood limits. Common (5–10% incidence), often undiagnosed, with high ADHD co-diagnosis (~40% of primary-school children with ADHD also have diagnosable ODD) — many symptoms overlap between the two.
Risk factors: child temperament (difficult to soothe as an infant, high motor activity, extreme emotional reactivity); parental factors (mental health problems, harsh/neglectful/inconsistent parenting, multiple caregivers); environment (low socioeconomic status, parental substance use).
DSM-5 criteria
A pattern of angry/irritable mood, argumentative/defiant behaviour, or vindictiveness lasting ≥6 months, with ≥4 symptoms from any category, shown with at least one non-sibling individual:
- Angry/irritable mood: often loses temper; touchy/easily annoyed; angry and resentful.
- Argumentative/defiant: argues with authority figures/adults; actively defies/refuses requests or rules; deliberately annoys others; blames others for own mistakes.
- Vindictiveness: spiteful or vindictive at least twice in 6 months.
Onset is usually gradual, evident before age 8. Higher rates of child abuse, school dropout and long-term mental health problems. May progress (without early intervention) to:
- Disruptive mood dysregulation disorder (DMDD) — severe, recurrent temper outbursts grossly out of proportion, >3/week for >12 months.
- Conduct disorder — behaviour violating others’ rights or societal norms (aggression to people/animals/property), often callous, lacking empathy.
If behaviour or mood puts the patient or others at risk of harm, this is an emergency-level situation in either disorder.
Management
Diagnosis follows the same multi-informant, specialist-led approach as ADHD.
- Parents: improve positive parenting skills; problem-solving/conflict- resolution/communication skills.
- Child: communication, problem-solving and anger-management skills.
- Family: counselling and support around relationships/home environment; address risk factors.
- School: social-skills/conflict-resolution training via teacher/school counsellor.
Psychological strategies and interventions have strong evidence for reducing ODD’s impact — earlier is better — and can prevent progression to DMDD/conduct disorder.
Medication: little evidence for medicating ODD alone. In mixed ADHD+ODD, trials of atomoxetine (Strattera) or clonidine (Catapres) have shown overall behavioural improvement. Seek specialist advice for any medication step-up in ODD.