The Medical Purpose Battlefield

Mental health conditions sit on a spectrum, and the line between subclinical distress and a diagnosable disorder is gradual, contested, and often invisible to the person experiencing it. Someone who today calls themselves stressed, low, or unable to sleep may tomorrow meet full diagnostic criteria.

That is what makes the boundary between a wellbeing tool and a digital mental health technology genuinely difficult to draw, and important to draw correctly.

The distinction is not about pathologising normal life. Wellbeing tools serve a real purpose, and framing a product as wellness rather than treatment can lower the barrier to engagement for people who would otherwise avoid help.

The distinction turns on what the product is actually for: one built to help healthy people through ordinary life sits in different regulatory territory from one addressing established conditions, whatever the label says. Mislabelling is not always deliberate; it can be drift, optimism, or simply not knowing where the line sits.

But the boundary does not move either way, and the two-step test below is how you locate it.

The medical device definition in the UK MDR 2002 and the EU MDR is the only rule in play: a product has medical purpose if it is intended for the diagnosis, prevention, monitoring, prediction, prognosis, treatment, or alleviation of disease, among other purposes. The MHRA's DMHT guidance v1.2 applies this to digital mental health and is explicit that medical purpose does not require diagnostic language.

On classification it states: “DMHTs that provide the probability of mental health conditions or probability of symptoms highly correlated to mental health conditions, where there is a reliance on this to determine clinical management options, may be considered as providing decisive information. As such, they would be considered as providing a ‘direct diagnosis’ as per rule 10 of the EU MDD and should be regulated as a class IIa medical device.”

The full definitions, function tables and worked examples are in the sources below.

Examine what the product does, not what it claims. A yes or possibly to any question below means gate one of the MHRA two-gate test is likely met; gate two, sufficient functionality, is covered in Module 2.

The first five questions map to the device-definition purposes; the last three catch the reliance and context routes that attach medical purpose without a named clinical function.

Function is one route to medical purpose. The manufacturer's own claims are another, and the two do not always agree.

The gap between what a product does and what it claims runs in both directions, and both are dangerous.

A product can understate: it performs a clinical function but is marketed as wellness to stay outside the framework. Step 1 catches this, because the function attaches medical purpose whatever the marketing says, and the result is an unregulated medical device on the market.

A product can also overstate: it does little of real clinical substance, or does it poorly and without evidence, but claims a clinical benefit in order to sell. Here the claim itself attaches medical purpose, and the user is left relying on a product for something it cannot safely deliver.

This step assesses the claim side, and the rule is plain: only signals the manufacturer controls can attach medical purpose, because intended purpose is the manufacturer's own statement of what the product is for. That covers the company website, the app store listing, investor and partnership material, and the company's social media.

Voices the company does not control, such as user reviews, journalists, or clinicians recommending the product on their own initiative, do not count unless the company endorses them. The table grades the signals advisors most often encounter.

Strong indicators in either step are enough. A product that performs a diagnostic or decisive-information function has medical purpose through function alone, whatever the marketing says.

A product with weak function but strong manufacturer signals has it through the signals, because the manufacturer has claimed the medical function. Both steps must be run and read together.

The most common real situation is drift: a product launched as wellness that accumulates medical purpose over time, as marketing softens, a partnership is announced, or a clinical deployment is celebrated. The moment the totality of signals crosses the line, the product is a medical device on the market without a pathway.

Denied intent does not change the regulatory position. If a product performs a function the MHRA treats as direct diagnosis or decisive clinical information, and it meets the sufficient-functionality gate, it is Software as a Medical Device.

Placing it on the UK market without registration, a clinical safety case, and the required conformity assessment is placing a non-compliant medical device on the market.

That is a criminal offence under the UK MDR 2002, enforced through the Consumer Protection Act 1987. The MHRA can prosecute, and the penalty on conviction is up to six months' imprisonment, an unlimited fine, or both.

The system relies on the manufacturer's stated intended purpose and runs on a presumption of honesty: that the manufacturer does its due diligence, including taking clinical and regulatory advice, to understand medical purpose and classify accordingly. That is not the same as the MHRA being passive.

It does not accept whatever is asserted and let a wrong classification stand because the manufacturer says it did not realise. Many unregulated products sit on the market today; that is an enforcement-capacity problem, not permission, and it offers no individual protection.

The MHRA can engage at any point, prompted by a complaint, an incident, a procurement query, or its own market surveillance, and the manufacturer then has to explain, cleanly and on the record, why the product was not treated as a medical device.