For professionals
Co-occurring autism and ADHD is common, under-recognised in adults, and newly relevant to primary care as state prescribing reform lands. This page holds the working set: presentation patterns, practical screeners, MBS mechanics, the state rules, and the two national guidelines that anchor the rest.
Last checked 8 August 2026
Written for GPs, psychologists and allied health. It summarises and links primary sources; the guidelines and the state regulators are the authorities, and this page carries the date it was last checked.
Consider co-occurrence when a presentation will not resolve into one frame: ADHD treatment that steadies attention while sensory overwhelm and rigidity persist; an autistic patient whose disorganisation and impulsivity exceed the autism; anxiety or depression that recurs on adequate treatment in a patient with lifelong social exhaustion and interest driven attention. The combination frequently hides behind mood labels for years.
Late diagnosed adults, women especially, tend to present at load transitions, promotion, parenthood, perimenopause, and the better the patient's camouflage the less the room shows. A developmental history reaching childhood, and a direct question about masking, retrieve what observation misses; the patient facing pages on this site cover the missed cohort and camouflage in plain language.
DSM-5 has permitted the dual diagnosis since 2013. Both national guidelines, linked below, recommend screening for the other condition when one is found.
ASRS v1.1, six items, for ADHD. AQ-10 for autistic traits, with the RAADS-R as the longer follow up. CAT-Q where camouflage is suspected, which in practice means most adult presentations that reached this page. Screeners gate the referral conversation; none diagnose.
Positive screens support a referral letter that actually helps the assessing clinician: developmental history, functional examples across settings, differentials already considered, current mental state, and the patient's own account of masking. That letter measurably shortens the assessment, and the assessment section of our resources page describes what a defensible report contains, which cuts both ways.
Where cost is the barrier, university psychology clinics run supervised assessment at reduced fees and are listed with links in the money section.
The telehealth psychiatrist assessment item 92435 rebates $467.45, once per patient per 12 months, with in person assessment attracting the same rebate. Under 25, the complex neurodevelopmental condition items fund structured assessment. Better Access covers psychological treatment on a mental health treatment plan; chronic condition items can fund allied health where criteria are met.
Prescribing is where geography decides: stimulants are Schedule 8, state law governs authority, and the reform wave is live. Queensland opened GP diagnosis and initiation for adults on 1 December 2025 with no additional training gate; South Australia runs a trained GP model; Victoria and New South Wales are training cohorts now with prescribing expected around September and October 2026; the remaining jurisdictions retain psychiatrist led initiation with continuation arrangements varying.
The current rule for every jurisdiction, with each regulator's page linked, is maintained on the state register, and each state guide links the controlling health department source directly.
Two national guidelines carry this field in Australia, and both are free. Everything on this site defers to them.
The NHMRC approved national guideline, developed by AADPA: assessment, diagnosis and management across the lifespan.
What to know. Free online in full. The support and treatment recommendations assume the co-occurrence question has been asked.
Autism CRC's national guideline for autism assessment in Australia, the standard adult and child assessment processes are measured against.
What to know. Free with registration. Its comprehensive-assessment model is the benchmark to quote when a report looks thin.
The professional body behind the ADHD guideline, running professional development and the practitioner community.
What to know. Its state prescribing summaries pair well with the plain language register on this site.
The public register of practitioner registration, the reference this site tells patients to check before paying anyone.
What to know. Patients arriving from this site have been told to verify names here; expect the question.
For ADHD, the six item ASRS v1.1 screener. For autistic traits, the AQ-10; the RAADS-R is longer and commonly used in adult pathways. The CAT-Q screens for camouflaging, which is the usual reason adult presentations, particularly in women, look subclinical in the room. All are screening aids, not diagnostic instruments.
Yes, since DSM-5 removed the exclusion in 2013, and co-occurrence is common enough that each condition's guideline recommends considering the other. Where both are plausible, a combined assessment reduces cost and the risk of attributing the whole picture to whichever condition presents loudest.
Queensland GPs can diagnose and initiate for adults since 1 December 2025; South Australian GPs can after additional training; Victoria and New South Wales expect trained GP prescribing from around September and October 2026; other jurisdictions retain psychiatrist led initiation, with several allowing GP continuation. The register on this site tracks the current state of each.
Three things dominate what patients tell us: a referral letter that records the developmental history rather than a one line request, a willingness to run shared care or continuation where state rules allow, and not being dismissed for arriving with self recognition, which the evidence on late diagnosed adults suggests is frequently accurate.