Major amendments to the Mental Health Act come into force: What this means for patients and professionals
10 March 2026
Our Mental Health Law team is issuing this update to highlight the most significant reforms to mental health legislation in over two decades. The Mental Health Act 2025 (MHA 2025) received Royal Assent on 18 December 2025, introducing substantial amendments to the Mental Health Act 1983, with the first set of changes now coming into effect.
These reforms modernise the legal framework governing compulsory detention and treatment, aiming to strengthen patient rights, promote therapeutic care, and align mental health law with modern clinical understanding and human rights standards.
A new legal landscape for mental health care
The MHA 2025 is not a replacement for the 1983 Act but a comprehensive set of amendments designed to transform how mental health services operate. It is underpinned by four statutory principles:
choice and autonomy,
least restriction,
therapeutic benefit, and
the person as an individual.
These principles will guide every clinical and legal decision under the amended Act, ensuring that patients’ rights and preferences are central to their care.
Key reforms now taking effect
Commencement of new provisions from 18 February 2026
Several significant amendments to the MHA 1983 came into force on 18 February 2026, including changes to:
Sections 42, 48, 71, 73, and 75, affecting restricted patients and the management of conditional discharge.
The creation of a new legal power allowing tribunals or the Secretary of State to impose conditions amounting to a deprivation of liberty (DoL) as part of a conditional discharge, provided this is necessary to protect the public from serious harm.
This corrects a long‑standing legal gap identified by the Supreme Court in Secretary of State for Justice v MM (2018).
A higher threshold for detention
A new “serious harm” test will apply to all detentions under sections 2 and 3, requiring clinicians to demonstrate that serious harm may occur to the patient or others, based on the nature, degree, and likelihood of risk.
This change aims to reduce unnecessary detentions and promote alternatives within the community.
New safeguards around treatment
The Act introduces strengthened rights for patients who refuse treatment, including:
A requirement for compelling clinical reasons before a capacitous refusal can be overridden.
Mandatory involvement of a Second Opinion Appointed Doctor (SOAD) for invasive or controversial treatments such as electro‑convulsive therapy (ECT).
The “Nominated Person” replaces the “Nearest Relative”
Patients will now be able to choose their own nominated person, who will receive enhanced consultation rights in relation to admission, treatment planning, and discharge.
This represents a significant shift towards personal autonomy and may greatly improve representation for patients who previously had no control over the identity of their statutory representative.
Restriction on Section 3 detention for autistic and learning‑disabled patients
The Act will prohibit the use of section 3 solely on the basis of autism or learning disability, unless there is a co‑occurring psychiatric disorder that justifies detention. Full implementation will follow once sufficient community provision is established.
Long‑term implementation
Although the first changes are already in force, the Government confirms that full implementation will take place over 8–10 years, with phased commencement following updates to the Code of Practice and significant workforce expansion.
Our firm will continue to monitor these developments and publish updates as further commencement dates are announced.
Our commitment
As a firm specialising in mental health law, we welcome these reforms as an important step towards a more humane and rights‑based framework. We remain committed to ensuring that patients, families, and professionals understand the implications of these changes and have access to expert legal support throughout the transition period.
For advice on how the Mental Health Act 2025 may affect you or your organisation, please contact our Mental Health Law team.
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