The Mental Health Act 2025: what you need to know

Overview

On 18 December 2026 the Mental Health Act 2025 received Royal Assent. It is not yet fully “in force”.

The Act follows many years of work by different governments to update the Mental Health Act 1983 to better reflect the modern understanding of mental illness.  The Mental Health Act 1983 was last amended in 2007 – nearly 20 years ago.

In 2018, the Independent Review of the Mental Health Act was published. Two of the main drivers of the review were to reduce detention rates and stark disparities of the use of the Act on some ethnic minority groups. The review’s final report identified four key principles that should be used as a 'basis for all actions taken under the act'. These principles form the foundation of the 2025 Mental Health Act:

• choice and autonomy
• least restriction
• therapeutic benefit
• the person as an individual. 

The updated Act will not be fully implemented immediately, but in stages over approximately a decade, subject to Spending Review decisions. This will give services time to train and recruit staff and to develop new services.  There will be a formal consultation on the existing Code of Practice, which we expect to begin in early 2026 with an updated Code of Practice published within around 12 months. 

The first phase of significant reforms should begin in 2028, however, the scope of this phase has not been fully defined. Changes that do not require significant workforce expansion are expected to be implemented in phase one.

Key aspects of the reforms

• Discharge: A new form of conditional discharge will be in place. This change was in response to the decision of the Supreme Court in November 2018. This is likely to only apply to a small number of patients and will begin in February 2026.
• A new time limit of 28 days will be set to transfer prisoners who need mental health treatment to a mental health hospital. This is expected to come in between 18 and 24 months post Royal Assent.
• Definitions: Four new definitions feature in the Act for “autism”, “learning disability”, “psychiatric disorder” and “Appropriate Medical Treatment”.
• Detention: The bar for detention will be higher: under both section 2 and section 3 there must be evidence that ‘serious harm may be caused to the health or safety of the patient or of another person’. However, we await the Code of Practice for a definition of “serious harm”.  Under section 3 a patient must be suffering from a “psychiatric disorder”, there must be a clear therapeutic benefit from the treatment and detention must be necessary.
• Community treatment orders (CTOs): will also have these stricter criteria and require the input of the community clinician. The government has committed to a review of CTOs; however, timelines and how the review of CTOs will impact on these changes is currently unclear.
• Nearest relative: provisions will be updated to provide for a nominated person (“NP”). Patients will be able to choose their NP, with safeguards in place. The NP will be able to exercise some additional rights compared to the current nearest relative role, such as the right to object to a patient being placed on a CTO or the right to be consulted about renewals.
• Consultation: Before discharging a patient, the responsible clinician (RC) must consult a person who has been professionally concerned with the patient’s medical treatment and who belongs to a profession other than that to which the RC belongs.
• Treatment: part IV of the Act is changing, with new provisions around making treatment decisions, the introduction of a “compelling reason” being required to give treatment without consent and amended provisions around electroconvulsive therapy (ECT).
• Care and treatment plans: which set out how current and future needs arising from or related to the patient’s mental illness when an individual is detained, will become a statutory requirement.
• Learning disabilities and autism: Integrated care boards (ICBs) and local authorities will need to seek to ensure the needs of people with learning disabilities and autistic people can be met without having to detain them, by increasing community provision for these groups. ICBs are already expected to maintain a dynamic risk register of people with learning disabilities and autism; however, the updated MHA will make this a  statutory duty.
• Advance choice documents (“ACDs”): NHS England and ICBs will have a statutory duty to ‘make arrangements’ to provide information and support that allows people to create ACDs. Clinicians will have a duty to “have regard” to ACDs so a reason will need to be given if a decision not to follow the ACD is made.
• Independent mental health advocates (IMHAs): Informal patients will have access to IMHAs, but will need to opt in. Patients detained under the Act will automatically have access to IMHAs, unless they choose to opt-out.
• Section 3:
  • Changes to renewals, frequency of tribunals and changes to second opinion appointed doctor (SOAD) roles.
  • The initial period of section 3 detention for treatment will be three months followed by renewals of three months, followed by six months and then a year.
  • People with a learning disability and autistic people without a co-occurring mental health issue will no longer be detained under section 3. However, this will only be enacted when the government is confident sufficient community services are in place.
• Police and prison cells will no longer be able to be used as a place of safety for adults experiencing a mental health crisis. In 2023/24 police cells were only used as a place of safety for around 1 per cent of the total number of those detained, and they are already outlawed for children and young people.

Analysis

Updating the Mental Health Act was long overdue. However, success will be dependent on the wider infrastructure to support it.

Changes for people with learning disabilities and autistic people 

Detention: There is agreement from the mental health and learning disabilities sector that people with a learning disability and autistic people should not be detained any longer than necessary, unless they have a co-occurring mental illness. 

Community provision: However, meeting the needs of these groups within the community will require a significant increase in community provision. During the pre-legislative stages and the passage of the Bill, the NHS Confederation and NHS Providers consistently raised this as a concern, and Lord Adebowale, chair of the NHS Confederation, tabled an amendment calling for a costed plan to build up capacity. Without a funded plan to build up this provision, there is a risk that the proposed changes to the legislation will never be enacted, and people will continue to be inappropriately detained.

Members would welcome clarity on how the government envisages local registers being resourced, supported and monitored

The government will only enact this change once it is confident there is sufficient community provision in place. However, the level of provision that is needed for the government to enact this change is not currently clear. If the change is enacted before a safe level of provision is in place, there is the risk of people with a learning disability and autistic people being held in criminal justice facilities, being at risk of homeless and presenting disproportionately in urgent and emergency pathways within the NHS. Members would also welcome clarity on how the government envisages local registers being resourced, supported and monitored.

Timeframes: More widely there are concerns from members that 28 days is not long enough for a thorough assessment to identify co-occurring mental disorder, due to the complexity that patients present with.

Staff: High vacancy rates across the sector also impact on staff capacity and that will need to be addressed.

Mental Capacity Act: The government has committed to monitoring the use of the Mental Capacity Act (MCA) as there are risks that this will be used as an alternative and has fewer safeguards for patients. 

The lack of clarity around the interface between the MHA and the MCA has been a broader, longstanding cause for concern for the system. There have been significant delays in implementing liberty protection safeguards (LPS), however, we are now expecting a consultation on LPS. Trust leaders have stressed the importance of the codes of practice for each Act providing clear guidance to assist in practitioners’ decision-making regarding which legal framework would be most appropriate.

ICBs and local authorities will be responsible for ensuring there is community provision available. The significant cuts and reorganisation of ICBs also presents a risk to long-term planning which will be required.

Reducing racial disparities

There is  the risk that excluding Part III from elements of the reforms will increase racial disparities related to detentions

PCREF: Reducing racial disparities in the use of the Act was a key driver of the reforms. While it is not included in the legislation, the patient and carer race equalities framework (PCREF), the anti-racism framework for mental health providers, is the key vehicle to reducing the racial disparities that exist within the application of the MHA and in wider services. All mental health providers must implement PCREF as part of the NHS Standard Contract. There are concerns that the understanding of the framework, as well as the lack of resources available, are hampering its implementation. This is a missed opportunity to address one of the more important issues with the MHA. 

Part III: There is also the risk that excluding Part III from elements of the reforms, which relate to patients involved in criminal proceedings, will increase racial disparities related to detentions. This is because black people are significantly more likely to access mental health support through the criminal justice system and are over-represented in secure mental health care settings.

Community treatment orders

Use: The racial disparities in the use of CTOs are incredibly stark – with black people being eight times more likely to be detained under a CTO than white people. There has been much debate about whether CTOs should be removed; however, there was consensus among NHS Confederation and NHS Providers members that, while acknowledging the disparity concerning CTO use, they can result in the least restrictive option. 

Review: The government has now committed to ‘reviewing’ CTOs. The details and timescales on this are not currently clear. Trusts largely welcomed revising the criteria for the use of CTOs and enhancing the professional oversight required.  It will be important for the government to monitor the effects of any changes to CTOs, including the impact of increasing evidence requirements, section 17 leave and readmission rates.

Advance choice documents

Duty: Making advance choice documents (ACDs) – which allow patients to set out ahead-of-time choices about their care if they become severely unwell – statutory was recommended by both the independent review and the pre-legislative scrutiny committee, due to the evidence that they can reduce racial disparities in the level of detentions. The legislation puts a duty on ICBs and local authorities to allow and support people to create them, and to provide a reason if clinicians decide not to follow an ACD. There is disappointment from some in the sector that there is no statutory duty to complete an ACD. It will be important to support ICBs and local authorities to effectively and equitably provide this support.

Issues: Guidance on how providers approach ACDs that were created by different trusts, how to digitally hold and connect records, and clarity on language within ACDs to ensure it is consistent (with the MCA and National Institute for Health and Care Excellence guidelines) will provide stronger safeguards for patients.

28-day time limit for prison transfers

Trust leaders have highlighted successful delivery of the time limit depends on bed and transport capacity, as well as hospital location. We would welcome the government clarifying how it intends to support services to achieve the 28-day transfer from prisons to hospitals, how services’ ability will be independently assessed before the 28-day limit is commenced, and how the government will monitor and report on delivery and impact.

Tribunals

The increased opportunities for patients to challenge their detentions are likely to increase the number of tribunal hearings and could require an additional 33 per cent expansion of the inpatient responsible clinician workforce. Given the 10-15 per cent national consultant psychiatrist vacancy rate, this will be very challenging. The legal aid budget would also need to increase. 

Consultation on expansion of definition of authorised persons

The Department of Health and Social Care has committed to a consultation in response to an amendment tabled in the House of Lords, but removed by government, to introduce a new category of “authorised person” who can carry out detentions under sections 135 and 136, which sought to enable health and care professionals to do so and potentially reducing the involvement of police. 

While in certain circumstances there are benefits to removing the current requirement for police to remain with a patient from the first contact until they are in a place of safety, there are significant concerns around the ability of health and care staff to carry out detentions. This includes the impact on therapeutic relationships between health and care staff and patients, and workforce capacity. 

Implementation

Baroness Merron, the minister responsible for mental health, described drafting and consulting on the Code of Practice as being the “first priority” after Royal Assent.  However, this is likely to take at least a year.  Updating the Code of Practice will translate the legislation into practice. The new criteria for detention, that ‘serious harm may be caused’ needs to be defined, otherwise there risks inconsistency on how the definition is interpreted, and the bar for detention may not be adjusted.  The devil will very much be in the detail.

Successful implementation will depend on ensuring the workforce and resources required to deliver the reforms in practice are in place

The Mental Health Act 1983 is a detailed and technical piece of legislation, and the reforms will have implications for the whole health and care system. However, the Act is only the legal framework in which the system for people with severe mental illness sits, and success of the reforms, will be dependent on the wider infrastructure to support it.

Successful implementation will depend on ensuring that the workforce and resources required to deliver the reforms in practice are in place. Capital funding to improve the safety and therapeutic environments of inpatient wards, and capacity of community services, are also needed.

Detaining fewer people will help reduce demand for expensive inpatient services. However, to detain fewer people, clinicians must be confident that community services are resourced and robust enough to support the level of need of patients

Detentions also often impact negatively on patient outcomes, increasing the need for, and therefore cost of, mental health support in the longer-term. Additional resources, such as supported housing, is vital to ensure people have access to step-down care, and more NHS and voluntary, community and social enterprise (VCSE) provision to support people from entering a mental health crisis is required. 

Without appropriate resourcing, there is a significant risk that many of the elements will not be successfully implemented

The 2024 impact assessment estimates £5.5 billion of monetised benefits due to fewer detentions, the cost of the reforms to be £5.3 billion for the areas of housing, health and social care and £313 million for costs to the justice system. The 2025 three-year Spending Review committed no additional funding to support the implementation of the reforms. Without appropriate resourcing, there is a significant risk that many of the elements will not be successfully implemented.

The NHS Confederation has led efforts to bring about long-awaited changes to the legislation. This includes: 

• Persuading the government to commit – on record – to laying an annual written ministerial statement setting out details of the work that has been done over the preceding 12 months to implement this legislation and plans for how we will implement future reforms. Baroness Merron referred directly to the NHS Confederation's chair Lord Adebowale’s amendment on this matter when announcing this.
• Securing support from several members of the House of Lords and the House of Commons for the amendments we drafted and led on.
• Briefing selected MPs and Lords ahead of parliamentary stages and securing mentions for the NHS Confederation in debates on the bill.
• Building a reputation with the government, MPs and members of the House of Lords as a key mental health stakeholder, which has led to subsequent engagement on behalf of NHS Confederation members. 

NHS Providers has also played an active role over the years to keep members informed and influence reform of the act on their behalf. This included:

• Responding to the white paper consultation and joint committee’s calls for written and oral evidence.
• Regularly voicing support for legislative reform, and the wider actions required to deliver ambitions in practice, in the media.
• Briefing parliamentarians in advance of the bill’s second and third readings, and producing member briefings on the white paper and the draft Bill.
• Organising meetings between DHSC and members, and meeting with DHSC and stakeholders, to discuss the bill’s development and implementation at key points.

How we are supporting members

• We will consult with members to highlight key issues in the consultations on the Code of Practice, the expansion of definition of authorised persons and the review of CTOs.
• We will continue to showcase members’ good practice to share innovation; raise the challenges members face during the implementation period with government and national bodies; and advocate for the development of a robust and achievable plan for implementation.
• We will continue to provide members with access to specialist advice and guidance on what the reforms mean for their organisation, patients and staff.  

Support from Mills & Reeve

As one of the UK’s largest and most experienced health and care sector teams, Mills & Reeve has over 200 lawyers working in healthcare, giving the firm an extraordinary level of strength and knowledge.  

As part of a national commercial law firm, the team can also draw upon expertise from colleagues in related sectors such as technology, government, education and life sciences.

They thrive on supporting their clients and their contribution to the sector, giving them creative solutions and informed advice based on a vast body of health and care sector experience.

Mills & Reeve help their clients make the right judgment in high-pressure situations – from consent and withdrawal of treatment to deprivation of liberty and inquests. Their clients, ranging from NHS providers and commissioners to independent sector providers, use their support as they design services and draft policies to meet their goals. 

The team support mental health providers and commissioners on the application of the MHA. From general wards to high-secure hospitals and everything in between, they frequently advise on high-profile and sensitive cases relating to patients detained under the MHA. Clients are often dealing with complex patients in high-risk arenas, so the firm’s support extends to investigations (both internal and independent), inquests and risk management training. Mills & Reeve help clients make the right judgment and deliver high-quality care to their patients. 

Alex Ruck Keene KC, a barrister specialising in mental health, mental capacity and healthcare law, has put together an updated version of the MHA 1983 with the changes to be brought in by the Act which can be accessed on the Mental Capacity Law and Policy website.