Are there different types of ADHD?
Inattentive, hyperactive, combined: what the research actually says now.
Published 18 September 2026. Written by Dr Chris Worfolk.
You may have heard that there are different types of ADHD: predominantly inattentive type, predominantly hyperactive-impulsive type, and combined type. But are these different types of ADHD, or merely different presentations?
What is ADHD?
ADHD is characterised by differences in attention and activity levels. ADHD individuals find that their attention is highly variable, often depending on how interested they are in a topic. Their brains "never switch off" and their physical activity levels may match this.
When formally assessing ADHD, these axes can be assessed separately. For example, the DSM-5 lists 18 characteristics of ADHD: nine for attention and nine for hyperactivity and impulsivity. Children need at least six from either category to reach the diagnostic threshold. Those aged 17 and over require five.
Historically, reaching the threshold in one of those categories would give you a subtype, whereas reaching the threshold in both categories would give you a combined type diagnosis.
Theories of ADHD
One of the challenging things about understanding ADHD is that we don't have a fully developed or agreed upon theory about what is going on.
Traditional theories talk about executive dysfunction, but don't explain why this is happening, or point to deficits in working memory, but this is not uniform across individuals with ADHD.
More modern theories look at the role of the default mode network (DMN) in preventing us from entering the task positive network (TPN) when we want to focus (Metin et al., 2015). ADHD has also been described as a kinetic cognitive style: in layman's terms, a "busy brain". However, no theory of ADHD has gained wide acceptance.
This is important because to understand if there are different types of ADHD, we first need to understand what ADHD is. And currently, we don't know.
Types vs presentations
Thinking on ADHD has moved away from types, and we now talk about presentations.
This change reflects the more current consensus that the internal experience of ADHD is largely similar, but that it can express itself in different ways.
Masking plays a role in this. Someone who compensates for inattention by being highly organised, excessively using lists, notes and spreadsheets, may come across as a hyperactive presentation.
Similarly, someone who has a lot to say, but after years of being chastised for not speaking at the "right time", may have learned to keep themselves quiet and sit on their hands. They may come across as an inattentive presentation.
In both of these examples, the experience of ADHD is the same, but the way it presents is different.
These presentations are not stable over our lifespan. At some periods of our lives, we may present in one way, and at another point in a different way. Typically, observable hyperactivity traits decline with age. This means that depending on what age we are when we have our assessment, we could be given a different subtype (Lahey et al., 2005).
Ultimately, research has concluded that the differences are not stable enough to describe ADHD presentation as different types (Willcutt et al., 2012).
As such, when we diagnose at Leeds Autism Practice, we do not draw a distinction between presentations, and simply give an outcome of ADHD.
Does this mean that there are no differences?
While we have replaced types with presentations, this does not rule out individual differences. Some people may fall on the more inattentive side and others may fall on the hyperactive side. But these are dimensions of ADHD, rather than different types.
It is important to go into the assessment process without prior expectations. If we just look at the surface presentation, we may miss a large part of someone's experience.
In my clinical experience, someone presenting as either inattentive or hyperactive is more likely to be masking their difficulties than they are to only be experiencing difficulties in one of these dimensions. That's not always the case, but it is always worth a thorough examination.
Are boys hyperactive and girls inattentive?
This idea isn't well supported by evidence and can be actively misleading if clinicians rely on these stereotypes.
Girls do appear more often in the inattentive category, but mostly in clinical samples, made up of people who have already been referred and assessed. When researchers instead look at community samples, where they screen everyone rather than waiting for referrals, the difference shrinks or reverses.
Gaub and Carlson (1997) found that in non-referred groups, girls with ADHD actually showed lower levels of inattention than boys, while in clinic-referred groups the two looked much the same. That pattern tells us something about who gets sent for assessment, not about how ADHD is experienced.
The idea that most boys are hyperactive is simply wrong. Predominantly hyperactive is the least common presentation in almost every sample studied, and it is rarer still in adults, because observable hyperactivity declines with age.
Research does support the idea that ADHD is under-diagnosed in women (Martin, 2024) and that more work is needed to understand how ADHD women present (Loyer Carbonneau et al., 2021).
Someone's sex tells you nothing useful about which dimension to look at. Both need examining, in everyone.
Conclusion
ADHD types have now been replaced by presentations. This reflects the fluidity of these presentations as they change over our lifespan. Hence, while ADHD may have different dimensions, they seem to share a common internal experience.
Any ADHD assessment needs to be aware that, to fully understand someone's experience, difficulties in the other axis may well be masked. A comprehensive assessment will always look at both.
References
Gaub, M., & Carlson, C. L. (1997). Gender differences in ADHD: A meta-analysis and critical review. Journal of the American Academy of Child & Adolescent Psychiatry, 36(8), 1036-1045.
Lahey, B. B., Pelham, W. E., Loney, J., Lee, S. S., & Willcutt, E. (2005). Instability of the DSM-IV Subtypes of ADHD from preschool through elementary school. Archives of general psychiatry, 62(8), 896–902. https://doi.org/10.1001/archpsyc.62.8.896
Loyer Carbonneau, M., Demers, M., Bigras, M., & Guay, M. C. (2021). Meta-Analysis of Sex Differences in ADHD Symptoms and Associated Cognitive Deficits. Journal of attention disorders, 25(12), 1640–1656. https://doi.org/10.1177/1087054720923736
Martin J. (2024). Why are females less likely to be diagnosed with ADHD in childhood than males?. Lancet Psychiatry, 11(4), 303–310. https://doi.org/10.1016/S2215-0366(24)00010-5
Metin, B., Krebs, R. M., Wiersema, J. R., Verguts, T., Gasthuys, R., van der Meere, J. J., Achten, E., Roeyers, H., & Sonuga-Barke, E. (2015). Dysfunctional modulation of default mode network activity in attention-deficit/hyperactivity disorder. Journal of Abnormal Psychology, 124(1), 208–214. https://doi.org/10.1037/abn0000013
Willcutt, E. G., Nigg, J. T., Pennington, B. F., Solanto, M. V., Rohde, L. A., Tannock, R., Loo, S. K., Carlson, C. L., McBurnett, K., & Lahey, B. B. (2012). Validity of DSM-IV attention deficit/hyperactivity disorder symptom dimensions and subtypes. Journal of abnormal psychology, 121(4), 991–1010. https://doi.org/10.1037/a0027347