Policy paper

Mental Health Bill 2025: fact sheet

Published 7 November 2024

Applies to England and Wales

Introduction: the Mental Health Act

The Mental Health Act 1983 (MHA) is the main piece of legislation that covers the assessment, treatment and rights of people with a mental health disorder. It provides a legal framework to authorise the detention and compulsory treatment of people who have a mental health disorder and are considered at risk of harm to themselves or others. Powers for compulsory admission under the MHA are set out in part 2 and part 3 of the act.  

Part 2 of the MHA deals with patients who are detained in hospital and have no criminal proceedings against them, or have criminal proceedings against them not related to their mental health. These are generally referred to as civil patients.  

Part 3 of the MHA is concerned with the care and treatment of offenders with severe mental health needs who are involved in criminal proceedings or under sentence.  

The Independent Review

The Independent Review conducted by Professor Sir Simon Wessely in 2018 identified that the current MHA is out of step with a modern-day mental health service and is in significant need of reform to make it work better for everyone. The reforms the review recommended were driven by the following problems:

• rising rates of detention
• racial disparities in detentions and community treatment orders
• poor patient experience
• the particular disadvantages felt by people with a learning disability and autistic people

These are explained below.  

Data from NHS England showed that the number of detentions rose by over a third in the lead up to the Independent Review between 2006 and 2016. According to the Care Quality Commission investigation monitoring the MHA, published in January 2018, this increase may have been due to a range of factors such as:  

• the 2007 reform of the MHA, which widened the definition of mental disorder and of treatment
• greater police awareness of mental health and more diversion from the criminal justice system
• changes in legal requirement for patients without capacity to consent to admission, which made it more likely that these patients would be assessed for detention under the MHA than in the past
• reduced availability of alternative community care
• population growth, including among groups that are more at relatively high risk of detention (for instance, those experiencing social exclusion and untreated drug and alcohol misuse)
• improvements in data quality, which also prevented double counting of detentions when hospital transfers took place

Following the Independent Review, a draft bill was published in 2022, setting out planned changes to the MHA. This underwent pre-legislative scrutiny (PLS) by a joint committee of both houses. The Joint PLS Committee produced a report and recommendations, to which the previous government responded in March 2024. Notably, the committee stated:

We welcome the draft Mental Health Bill. It makes important changes to introduce more choice, accountability and oversight into the use of the MHA.

Facts and figures 

Recent data from NHS England showed that the number of detentions continued to increase from 2016 to 2017 up to 2020 to 2021. However, there were decreases in the number of detentions for the next 2 years up until 2022 to 2023, before increasing again in 2023 to 2024. 

There was a change in methodologies for detentions data in 2016 to 2017, which means that figures from 2016 to 2017 onwards are not directly comparable to previous years. However, recent data has also shown: 

• in 2023 to 2024 there were around 52,500 new recorded detentions under the MHA in England. This is an estimated 2.5% increase in detentions from 2022 to 2023, following a 7.7% fall in detentions from 2021 to 2022
• most people who are detained under the MHA are detained under part 2 of the act. Over two-thirds (70.8%) of all people detained in hospital on 31 March 2024 were detained under part 2 of the MHA, while nearly a third (29.2%) were detained under part 3 of the MHA
• in 2023 to 2024, 963 detentions were recorded for children and young people aged 17 and under; over two-thirds (689) of these were aged 16 or 17
• in the same period, black people were 3 and a half times more likely than white people to be detained under the MHA, and 7 times more likely to be placed on a community treatment order (CTO)

Data from NHS England also showed that the number of inpatients with a learning disability and autistic inpatients subject to the MHA has fallen from 2,500 in March 2015 to 1,880 in September 2024. However, a larger proportion of inpatients with a learning disability and autistic inpatients are now subject to the MHA than previously: 93% in September 2024 compared to 86% in March 2015.

Data from the Ministry of Justice showed a total of 1,746 restricted patients were admitted to hospital for treatment under the MHA in 2023 in England and Wales, a 5% increase from 2022. As of 31 December 2023, there were 7,833 restricted patients, of which 4,648 were detained in hospital and 3,185 conditionally discharged. Restricted patients are offenders subject to special controls by the Secretary of State for Justice - for example, after a court sentence or transfer from prison.