Combined-Type ADHD in Adults: Signs and Diagnosis

Short answer: Combined-type ADHD, formally ADHD combined presentation, is diagnosed when a person meets the symptom thresholds for both inattention and hyperactivity-impulsivity,¹ with symptoms that have been noticeable for at least the past six months.² In adults it can look like distractibility, disorganisation and forgetfulness alongside restlessness, impatience, interrupting and blurting things out.³ It’s assessed against the same criteria as the other presentations, and the Australian ADHD Guideline’s treatment recommendations don’t differ by presentation.⁴

What is combined type ADHD?

ADHD is usually diagnosed using the DSM-5 criteria, which split the 18 ADHD symptoms into two groups: inattention and hyperactivity-impulsivity.⁵ A person’s presentation depends on which group, or groups, meet the symptom threshold:

• inattentive presentation: the threshold for inattention is met
• hyperactive-impulsive presentation: the threshold for hyperactivity-impulsivity is met
• combined presentation: the thresholds for both are met.¹

For people aged 17 and over, the threshold is five symptoms in a group; for children it is six.² So an adult with combined-type ADHD has at least five frequent symptoms of inattention and at least five of hyperactivity-impulsivity.

In DSM-IV these were called subtypes. DSM-5, published in 2013,⁶ replaced them with presentations that map directly onto the old subtypes,⁵ so “combined type”, “combined subtype” and “combined presentation” all describe the same thing. See ADD vs ADHD for how the names have changed.

What does combined ADHD look like in adults?

Adults with combined-type ADHD have symptoms from both groups. Everyone has some of these at times. In ADHD they are frequent, several were present before age 12, and they cause problems in at least two areas of life, such as home and work.²⁷

Inattention

• making careless mistakes at work, or finding it hard to sustain attention
• not seeming to listen when spoken to directly
• not following through on instructions or finishing tasks
• finding it hard to organise tasks, and avoiding tasks that need sustained mental effort
• losing things such as keys and paperwork
• being easily distracted and forgetful in daily activities³

Hyperactivity and impulsivity

• fidgeting, or finding it hard to stay seated
• feeling restless or driven to stay busy
• impatience, and trouble waiting your turn
• talking more than intended
• interrupting conversations or speaking before others have finished³

In adults, hyperactivity can be more subtle than in children, such as feeling restless and unable to relax.¹ Impulsivity means acting or deciding without thinking through the consequences,² and in adult life it can look like overspending, risk-taking or conflict with other people.⁸ Adults with ADHD may also have rapid changes in mood and sleep difficulties, and may find it harder to keep a job or maintain relationships.³ Difficulty regulating emotions is common in ADHD at every age and adds substantially to the problems it causes.⁹

At work, the two sides can show up together: starting several tasks and finishing few, losing track of deadlines, and finding a long meeting hard to sit through without fidgeting or jumping in before others have finished. For a fuller list of symptoms, see ADHD symptoms in adults.

How common is combined-type ADHD?

The Australian ADHD Guideline notes that the inattentive presentation is the most prevalent,¹ so combined-type ADHD is less common than inattentive ADHD overall.

Hyperactive and impulsive symptoms are the most visible symptoms of ADHD, and many children and adults with ADHD may not show them.⁴ Inattention, by contrast, can be less obvious.² So people whose ADHD includes hyperactivity and impulsivity, including those with the combined presentation, may be noticed more readily than people with inattention alone.

There are no national survey figures for how common each presentation is in Australian adults. Australia’s national adult mental health survey didn’t measure ADHD,¹⁰ and the Australian ADHD Guideline says adult ADHD in Australia is likely to be similar to international estimates of 2–6% of adults.¹

Can your ADHD presentation change?

Yes. Presentations aren’t fixed. A child’s presentation can change as they grow and their circumstances change,¹¹ and in adults hyperactivity and impulsivity may decrease or show up as extreme restlessness, while inattention may persist.²

So someone diagnosed with combined-type ADHD as a child may meet the criteria for the inattentive presentation as an adult. That doesn’t mean their ADHD has gone. Inattention can still make it hard for adults to manage their time and stay organised.⁷

Inattention can also become more noticeable over time. It tends to become more evident as academic and cognitive demands increase,¹ and inattentive symptoms may not be identified until secondary school or later, when organisation and independent study or work become more demanding.⁴ Read more in inattentive ADHD in adults.

How is combined-type ADHD diagnosed?

The process is the same for every presentation. A clinician will look for:

• at least five symptoms in each group for people aged 17 and over, occurring frequently and noticeable over at least the past six months²
• several symptoms present before age 12⁵
• symptoms in at least two settings, such as home and work, that interfere with daily functioning¹²
• no other condition that better explains the symptoms.¹¹

There is no single test for ADHD: diagnosis involves a comprehensive assessment, which can include a medical and family history, questions about how symptoms affect your relationships and work, and interviews with people who know you well.³ Because ADHD starts in childhood, you may be asked for school reports.⁷

Other conditions are common: up to 80% of adults with ADHD have at least one other mental health disorder, most often depression, bipolar disorder, anxiety or a substance use disorder.¹ An assessment should also look for those, and for alcohol or drug use that might be contributing to your difficulties.³ If you’re struggling in the meantime, Lifeline (13 11 14) offers crisis support and the National Alcohol and Other Drug Hotline is 1800 250 015. In an emergency call 000.

How is combined-type ADHD treated?

There isn’t a separate treatment for combined-type ADHD. The Australian ADHD Guideline’s recommendations apply to every presentation,⁴ and include:

• Education about ADHD (psychoeducation): information on what causes ADHD, its possible consequences, and the treatment options.⁴
• Psychological strategies: cognitive behavioural interventions should be offered to adults with ADHD, and ADHD coaching can be considered as part of a treatment plan.⁴
• Lifestyle support: asking about sleep, diet and physical activity, and offering strategies or a referral where needed.⁴
• Medication: stimulant medicines are recommended as the first-line medicine when ADHD symptoms are causing significant impairment. Non-stimulant medicines can be offered to adults when stimulants aren’t suitable, aren’t tolerated or haven’t worked.⁴

Practical supports can help with the day-to-day effects too, such as coaching for organisation, time management and planning, and workplace adjustments like flexible work practices.³

The guideline recommends combining approaches, with a plan that fits the person’s preferences, needs and goals.⁴ Your doctor or pharmacist can explain the options, including possible side effects. Don’t start or stop a medicine without talking to your doctor. For non-medication approaches, see how to manage ADHD without medication.

Frequently asked questions

What is combined type ADHD?

It’s the presentation of ADHD diagnosed when a person meets the symptom thresholds for both inattention and hyperactivity-impulsivity, with symptoms noticeable over at least the past six months. DSM-5 calls it the combined presentation.

What does combined ADHD look like in adults?

A mix of inattention, such as distractibility, disorganisation and forgetfulness, with hyperactivity and impulsivity, such as feeling restless and unable to relax, impatience, interrupting and acting without thinking things through.

Is combined type ADHD the most common type?

Not overall. The Australian ADHD Guideline notes that the inattentive presentation is the most prevalent. Hyperactive and impulsive symptoms are more visible, though, so they may be noticed more readily.

Can combined ADHD turn into inattentive ADHD?

It can. Presentations can change over time, and in adults hyperactivity and impulsivity may decrease or show up as restlessness while inattention may persist. A change in presentation doesn’t mean ADHD has gone.

How is combined type ADHD treated?

The same way as other presentations. The Australian ADHD Guideline recommends education about ADHD and a plan that fits the person, which can include cognitive behavioural strategies, coaching, lifestyle guidance and medication where appropriate.

Next steps

Read ADD vs ADHD and how to get an ADHD assessment in Australia, or start with the free ADHD self-assessment.

This article is general information only and is not medical advice. Only a qualified health professional can diagnose ADHD. ADHD GP is a private telehealth clinic staffed by AHPRA-registered Australian GPs.

Book your ADHD assessment

References

1. Australian ADHD Professionals Association. About ADHD (Australian ADHD Guideline). 2022. adhdguideline.aadpa.com.au — ADHD affects 6–10% of Australian children and 2–6% of adults; heritability 70–80%; symptoms begin before 12 though diagnosis may come later; 60–86% persist into adulthood; inattentive presentation most prevalent; up to 80% of adults have another mental health condition; describes executive-function, brain-maturation and dopamine differences.
2. American Psychiatric Association. What is ADHD?. 2022. www.psychiatry.org — ADHD is one of the most common mental disorders affecting children; symptoms must be present before age 12; an estimated 8.4% of children and 2.5% of adults have ADHD.
3. Better Health Channel (Victorian Government). ADHD — adults. 2026. www.betterhealth.vic.gov.au — About 7 in 10 children continue to experience ADHD symptoms as adults; treatment can include education, psychological support, coaching, practical strategies and medication.
4. Australian ADHD Professionals Association. Australian ADHD Guideline — summary of recommendations. 2022. adhdguideline.aadpa.com.au — Medication is the most effective treatment for core symptoms, with non-medication treatments adding support (3.1.1); diagnosing clinicians should be registered and trained in ADHD assessment (2.1.1); the diagnosis must be confirmed before starting medication (5.1.2); CBT should be offered to adults (4.2.11); stimulants are first-line for impairing adult ADHD, with heart rate, blood pressure, weight, sleep, mood and anxiety monitored during titration; co-occurring conditions get best-practice treatment.
5. American Psychiatric Association. Highlights of Changes from DSM-IV-TR to DSM-5. 2013. www.psychiatry.org — DSM-5 kept the same 18 ADHD symptoms but replaced subtypes with presentation specifiers, required several symptoms before age 12 (previously 7) and set a five-symptom threshold for adults.
6. American Psychiatric Association. DSM History. 2026. www.psychiatry.org — DSM-III was published in 1980, DSM-III-R in 1987, DSM-IV in 1994, DSM-5 in 2013 and DSM-5-TR in March 2022.
7. healthdirect (Australian Government). Attention deficit hyperactivity disorder (ADHD). 2025. www.healthdirect.gov.au — ADHD is a neurodevelopmental condition that begins in early childhood; around 1 in 20 people in Australia has ADHD; it is partly genetic; an adult diagnosis requires evidence that symptoms began in childhood; learning difficulties can occur alongside it.
8. Healthy Male (funded by the Australian Government). Adult ADHD diagnosis in Australia: What you need to know. 2026. healthymale.org.au — In adults, impulsivity can look like excessive spending, risk-taking, conflict with others, interrupting and talking excessively; managing finances and meeting work deadlines can be difficult.
9. Shaw P, Stringaris A, Nigg J, Leibenluft E. Emotion dysregulation in attention deficit hyperactivity disorder. American Journal of Psychiatry. 2014. PubMed PMID 24480998 — Emotion dysregulation is prevalent in ADHD throughout the lifespan and a major contributor to impairment.
10. Australian Bureau of Statistics. National Study of Mental Health and Wellbeing 2020–2022. 2023. www.abs.gov.au — Assessed three groups of mental disorders — anxiety, affective and substance use disorders — and did not measure ADHD.
11. Better Health Channel (Victorian Government). Attention deficit hyperactivity disorder (ADHD). 2026. www.betterhealth.vic.gov.au — ADHD has a strong genetic component and is not caused by parenting style.
12. Parliament of Australia — Senate Community Affairs References Committee. Assessment and support services for people with ADHD — Chapter 1. 2023. www.aph.gov.au — ADHD occurs in about 6–10% of Australian children and adolescents and 2–6% of adults; heritability is estimated at 70–80%; Deloitte estimated 814,500 Australians living with ADHD in 2019 at a cost of $20.42 billion.

Sources were last checked on 5 October 2026. See all sources used on this site on our Sources page.