How big is the private self-pay market for ADHD and autism assessments in England?

Patients in England pay an estimated £51m to £157m a year for their own ADHD and autism assessments, with a midpoint of about £90m. The range is wide because it depends most on the share of people who pay. It comes down to five points:

1. Patients who pay each year come by two routes: through an NHS waiting list first, or straight to private.
2. The estimate rests on four inputs: we have data for two (NHS referrals and prices), and two are assumptions based on surveys (the share who pay and the share who go straight to private).
3. About 35,000 to 113,000 people pay each year, worth an estimated £51m to £157m, out of about 547,000 who seek an assessment.
4. People already on NHS waiting lists could be worth a one-off £66m to £200m on top of the yearly market, and adults with undiagnosed ADHD £18m to £193m, but each would be paid only once.
5. Private healthcare use has nearly doubled since 2023, and more people go straight to private as NHS waiting lists grow.

How we built this. The driver tree in section 1 shows every input and how they combine. Each input has a source next to it. The share who pay comes from surveys of all private healthcare, shown as a range, and the calculator in section 3 lets you change it, the share going straight to private and the price.

1. Patients who pay each year come by two routes: through an NHS waiting list first, or straight to private#

Driver tree: how we size the yearly self-pay market, starting from NHS referralsEach box is calculated from the boxes to its right. The rest of the article refers to the boxes by letter.Calculated from the boxes to its rightData: NHS figures or published pricesAssumption from surveys of private healthcareNo dataYearly self-pay marketAPatients who pay in a yearBEveryone seeking an assessment in a yearCNHS referrals in a year+DPatients who go straight to private (IHPN benchmark: 44% of A)×EShare who pay×FPrice per assessmentA splits by route, using IHPN's benchmark: 56% join an NHS waiting list first and then pay; 44% go straight to private D.iNot used: B could also be built as the population × the share with ADHD or autism × the share who seek help in a year, but no survey measures the share who seek help in a year.Source and notes

Why we start from NHS referrals

• Ideally, B would be the population × the share with ADHD or autism × the share who seek help in a year.
• No survey measures the share who seek help in a year, so we build B from the data available: NHS referrals and IHPN's benchmark.
• A survey asking who sought an assessment in the past year, and by which route, would size the market more directly.

Why this is a yearly figure, not a one-off total:

• Leaving out the share who seek help in a year gives a one-off total instead: what everyone with ADHD or autism might ever pay.
• That money is paid only once, so it can't be added to the yearly market. Services we speak to often skip this step, which makes the market look larger than the revenue available each year.
• Section 4 sizes two of these one-off totals.

2. The estimate rests on four inputs: we have data for two, and two are assumptions based on surveys#

• NHS referrals: the ADHD count is an upper bound: it includes referrals that may be for ADHD, and anyone referred for both ADHD and autism is counted twice.
• Share who pay: the surveys count everyone who paid, whichever route they took, so the share applies to everyone seeking an assessment, not only to NHS referrals.
• The 44% share covers all UK private healthcare, including GP appointments.

3. About 35,000 to 113,000 people pay each year, worth an estimated £51m to £157m#

Each type of assessment is worked out the same way, and the four add up to the total:

Illustrative estimateThe yearly self-pay market is about £51m to £157m, depending most on the share who payEach block is one type of assessment: its width is the number of people who want that assessment a year, and the amber band is the share who pay. Move the three assumptions under the chart to see how the market changes.Adult ADHD237k people21k pay (9%)£21mAdult autism90k people8k pay (9%)£15mChild ADHD116k people17k pay (15%)£22mChild autism103k people16k pay (15%)£32mPay for their assessmentDon't pay% of people seeking an assessment who pay privatelyiAdult: 9%Child: 15%LowerMidpointUpper% of self-payers who go straight to privatei44%0%IHPN 44%70%Price per assessmentiAdult: ADHD £995, autism £1,850Child: ADHD £1,250, autism £2,050NHS guideCurrentWith these settings, about 547k people seek an assessment a year and about 62k of them pay, worth about £90m a year: £50m from patients who joined an NHS waiting list first and £40m from patients who went straight to private.Limitations• The share who pay comes from surveys of all adults and all private healthcare, not people seeking an ADHD or autism assessment.• The 44% going straight to private covers all UK private healthcare, including private GP visits.• Assessments paid for by insurers or employers aren't included; insurers mostly cover them only as an add-on that employers buy.• Assessments only: titration, follow-ups and prescriptions are extra.Source and notes

At the midpoint:

• About 547,000 people seek an assessment a year (B): 520,000 NHS referrals (C) plus about 27,000 who go straight to private (D).
• About 62,000 of them pay (A): 35,000 after joining an NHS waiting list and 27,000 straight to private.
• About 7% of NHS referrals go on to pay privately, or 4% to 12% across the range. This follows from the 44% benchmark: the 56% of A who join a waiting list first, divided by NHS referrals.

How much each assumption matters:

• The share who pay matters most. From the lower to the upper estimate, the market runs from about £51m to £157m. Cost holds many people back: of people waiting for an ADHD assessment who weren't considering going private, 61% said they couldn't afford it (Healthwatch England, 2025).
• Price matters next. If private prices fell to NHS guide prices (£860 adult ADHD, £1,163 adult autism), the midpoint would drop from about £90m to about £66m.
• The 44% going straight to private barely matters. Anywhere from 25% to 55% gives £88m to £91m, because it mostly changes how the market splits between the two routes.

Show our workingHide our working

Why A is worked out this way: D is 44% of A, so A appears on both sides of the equation. Solving for A gives the second line:

A Patients who pay = E share who pay × (C NHS referrals + D 44% of A)SolvedA = E × C ÷ (1 − 44% × E)

It is worked out separately for adults and children, because their share who pay differs, and for ADHD and autism, because their prices differ. The results are then added up.

Calculated (midpoint, with the range in brackets)

Box	Value	How
A. Patients who pay	62,000 (35,000 to 113,000)	E × C ÷ (1 − 44% × E)
D. Patients who go straight to private	27,000 (16,000 to 50,000)	44% × A
B. Everyone seeking an assessment	547,000 (535,000 to 569,000)	C + D

Output

	Value	How
Yearly self-pay market	£90m (£51m to £157m)	A × F

Illustrative estimateAt the midpoint, about 62,000 patients pay about £90m a yearThe driver tree with the midpoint figure in each box. Adults and children, and ADHD and autism, are worked out separately and then added up.Calculated from the boxes to its rightData: NHS figures or published pricesAssumption from surveys of private healthcareYearly self-pay market£90mAPatients who pay in a year62,000BEveryone seeking an assessment in a year547,000CNHS referrals in a year520,000+DPatients who go straight to private (IHPN benchmark: 44% of A)27,000×EShare who payAdults 9%, children 15%×FPrice per assessment£995 to £2,050, by typeSource and notes