Welcome to Did You Know? — Hempsons’ publication designed to keep you up to date with the changing legal landscape affecting health and social care providers, commissioners and professionals.

In this edition, we focus on the Mental Health Act 2025, which is set to deliver the most substantial reform of mental health legislation in over 40 years. Some key sections have already come into force, however, further developments are expected later this year, including a draft Code of Practice and further commencement dates for the rest of the Act. Here, our mental health law experts highlight what the Act will be changing, why it matters, and what organisations need to prepare for.

We hope you find this edition helpful. If you would like advice, training or support in preparing for implementation, we would be delighted to assist.

One of the most significant legal developments in the 2025 Act is the introduction of the category of patients with a ‘psychiatric disorder’, which is narrower than the previous concept of “mental disorder”.

Both concepts are used within the Act, but importantly:

• Autism and learning disabilities are not included in the concept of “psychiatric disorder”. The Act therefore draws a principled distinction between individuals with those diagnoses, and those with other diagnosed psychiatric conditions, laying the groundwork for changing how the Act’s powers apply to the different groups.
• When enacted, the Act will change who may be detained under section 3. Detention for treatment under section 3 will apply only to those with a ‘psychiatric disorder’. It will no longer be possible to detain an individual on the grounds of a diagnosis of autism or learning disabilities alone.

This represents a major shift in the legal basis for compulsory admission and reflects Parliament’s intention to reduce inappropriate detention of people with autism and learning disabilities.

When enacted, the Act will change the threshold for compulsory admission and treatment in several important ways.

• Detention for the purposes of assessment under section 2 will require clinicians to establish a risk of ‘serious harm’ to the health or safety of the patient or of another person; and also to satisfy themselves that the patient ‘ought’ to be detained in light of:
  • the nature of the harm
  • the degree of harm
  • the likelihood of harm.
• Detention for treatment under section 3 will be available only for patients with a ‘psychiatric disorder’ (no longer only a mental disorder), and even then only available where:
  • A risk of serious harm is established – mirroring the changes to section 2: and
  • Treatment is necessary and cannot be provided unless the patient is so detained; and
  • Clinicians are satisfied that ‘appropriate medical treatment’ is available to the patient as a result, itself defined for the first time in the Act as treatment having ‘a reasonable prospect of alleviating, or preventing the worsening of’, the disorder, its symptoms or manifestations.

This imposes a new requirement of therapeutic benefit to the patient, in addition to requiring clinicians to consider both the ‘serious harm’ requirement and whether the treatment can be provided anywhere other than in hospital.

Taken together, these requirements will considerably tighten up the legal criteria needed to be met to justify detention.

The 2025 Act replaces the long‑criticised concept of a patient’s “nearest relative” acting as their representative and as the protector of their interests, with a more modern approach that enables patients to elect a ‘nominated person’ for themselves.

Under the new regime:

• Individuals can choose their own nominated person, provided they have capacity (if 16+) or competence (if under 16) to do so. The AMHP must appoint a nominated person if the individual is unable to choose.
• In reflection of the patient’s role in electing their own nominated person, the nominated person will also have a wider role in relation to treatment, including greater involvement in the decision making process by clinical teams.

This reform places patient autonomy and voice at the heart of the Act, and moves away from the earlier assumption inherent in the original Act that a patient’s family members (as opposed to others) are best placed to act as their representative.

The powers of the Mental Health Tribunal will be increasing, both in scope and in an enhanced ability to more regularly consider particular cases. Under the Act:

• Patients will be able to access to the Tribunal, at 3 months post an initial decision to detain, 3 months after that, 6 months, and then annually. This will significantly increase patients’ opportunities to challenge their detention.
• The Tribunal has been granted additional powers to impose conditions amounting to a DOL on a patient who is conditionally discharged – these powers came into effect on 18 February 2026.
• The Tribunal has also been granted a further set of powers which, when in force, will enable it to ensure that responsible aftercare bodies and clinical teams prepare a ‘care and treatment’ plan for certain patients, and empowers the Tribunal to scrutinise those plans in the course of reaching its decisions.

This represents a notable expansion of Tribunal jurisdiction and is expected to increase the Tribunal activity significantly, which will have a knock on impact on provider organisations.

Our experienced team advise and act for a range of health, social care, and charitable organisations on mental health law, and are one of the largest dedicated mental health teams in the country.

We aim to provide sensitive, pragmatic and efficient advice to enable and support clear, cost-effective decision making which puts patients at the heart of their care delivery. Our services include:

• Pragmatic and plain-speaking advice about the current legal framework
• Expert advice on particularly complex cases, including those involving:
  • Homicides and public safety risks
  • Complex service users, with overlaid issues of capacity and consent, Advance Directives & Lasting Powers of Attorney; and
  • Children & young people, the scope of parental responsibility, and safeguarding challenges
• Robust advice, preparation and legal representation before Mental Health Tribunals, in the Court of Protection, in judicial review proceedings, and at inquests
• An out of hours service to ensure timely support even in urgent situations.

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