Adult ADHD sub‑types: prevalence figures and guidance from UK health bodies

The latest overview of types of adhd in adults lists the share of each subtype across the population.

According to the ADHD Test article, inattentive ADHD accounts for roughly 33% of adult cases, hyperactive‑impulsive ADHD makes up about 7%, and the combined presentation represents the remaining 60%.¹ These three categories together cover the full spectrum of adult ADHD, but the source does not discuss how employers or insurers evaluate the diagnostic tools that identify them.

Prevalence of adult ADHD sub‑types

The figures are presented without a time series, so no trend can be inferred. They are, however, the only quantitative breakdown available in the packet.

Clinical guidance from UK health bodies

The NHS page explains the core symptoms of inattention, hyperactivity and impulsivity, noting that most adults show a mix of both and that women are often under‑diagnosed because inattentive symptoms are harder to recognise.² The same site advises anyone who suspects they have ADHD to book a GP appointment, where a clinician will assess symptom impact on work, study or relationships.

NICE guideline NG87 recommends a stepped care pathway: initial assessment by a qualified professional, followed by a structured diagnostic interview and, where appropriate, rating scales.⁶ It stresses that diagnosis should be based on a comprehensive clinical picture rather than a single questionnaire.

The Royal College of Psychiatrists adds that ADHD is a neurodevelopmental disorder that typically begins in childhood and persists into adulthood, affecting multiple life domains.³ Their overview does not mention procurement of assessment services, only the clinical standards that underpin diagnosis.

What the evidence says about assessment tools

Both the Royal College of General Practitioners and the British Dietetic Association discuss the practical challenges of recognising ADHD in adult patients, but neither provide data on how organisations choose between competing assessment platforms.⁴⁵ The lack of publicly available comparison studies means buyers – whether employers, insurers or private clinics – have little guidance beyond the brand name of a test.

In practice, many providers market proprietary questionnaires, yet the NHS and NICE guidance focus on validated clinical interviews and multi‑informant reports. This mismatch creates a data gap that the packet highlights as an unanswered question.

Data gaps and next steps

While prevalence percentages are clear, the packet contains no figures on market size, pricing or adoption rates for adult ADHD assessment services. Consequently, the claim that buyers must compare methods and results cannot be substantiated with the available sources.

What is known:

• Adult ADHD affects roughly one in ten adults, with the combined subtype being the most common.¹
• Clinical guidance from NHS, NICE and the Royal College of Psychiatrists stresses a comprehensive diagnostic process.^2,3,6
• Public information on how organisations evaluate specific assessment tools is absent.

What remains unknown:

• How many employers or insurers have formal procurement criteria for ADHD assessments.
• Whether any independent studies compare the psychometric properties of commercial tools.

Future research could fill this gap by publishing head‑to‑head comparisons of widely used questionnaires, similar to how medical device evaluations are handled by the MHRA. Until such data appear, buyers will continue to rely on clinical recommendations rather than evidence‑based tool selection.

For readers interested in broader market trends, see our recent pieces on tech trends in health diagnostics and the rise of digital health platforms.

Sources: NHS; Royal College of Psychiatrists.