The differences between the conceptualisation of capacity under the Mental Health Act 1983 (MHA) and the Mental Capacity Act 2005 (MCA) in the UK are significant, particularly in their approaches to determining capacity for consent to treatment.
The Mental Health Act 1983 (MHA) and the Mental Capacity Act 2005 (MCA) both address issues of capacity and consent, but they do so in different contexts and with different legal standards. There is no explicit presumption of capacity under the MHA 1983. Section 58(3) of the MHA requires that, except in certain circumstances, a patient must be certified in writing as being capable of understanding the nature, purpose, and likely effects of the proposed treatment and having consented to it.
This article explores
- The distinctions between MCA and MHA concepts of capacity/consent, focusing on the tests or requirements for capacity.
- An exploration of capacity/consent concepts in the MHA Bill 2021.
The MHA does not explicitly declare specific tests for assessing capacity, and instead relies on the clinical judgment of the responsible clinician. In contrast, the MCA provides a more detailed framework for assessing capacity, which applies to all adults who may lack capacity to make decisions about their care and treatment. The MCA sets out a two-stage test for assessing capacity: first, whether the person has an impairment or disturbance in the functioning of their mind or brain; and second, whether this impairment or disturbance means that the person is unable to make a particular decision at the time it needs to be made. The MCA also sets out a presumption of capacity, meaning that individuals are assumed to have capacity unless it is established otherwise.
The MHA Code of Practice suggests that the test of capacity is aligned to the concepts in the Mental Capacity Act (2005). However, there is nothing in law that states that the principles and/or tests of capacity under Mental Capacity Act (2005) are applicable in the MHA 1983 (Amended 2007).
The mind map embedded below shows how capacity is assessed under Mental Capacity Act (2005). [May not show on all devices].
Aspect | MHA 1983 | MCA 2005 |
---|---|---|
Definition | Understanding nature/purpose/effects | Understand, retain, weigh, communicate |
Presumption of Capacity | No statutory presumption | Presumed unless disproven |
Communication | Not required of agreement is not a specific requirement. | Required |
Threshold | Binary [No statutory requirement to assist or facilitate capacity] | Decision-specific |
Scope | Detained patients and some patients on CTOs. Mental disorders only. | All adults, all decisions (except where other legislation has priority. |
Fluctuating Capacity | Implicitly addressed via snapshots | Explicitly recognised |
ANALYSIS
Definition and Scope of Capacity
MHA 1983: The MHA does not explicitly define “capacity” in its statutory text. Instead, its framework for consent to treatment (e.g., in Form T2) relies on the phrase: “capable of understanding the nature, purpose and likely effects of the treatment” . T2 forms are a certificate issued by the Approved Clinician under S58. This test focuses narrowly on understanding the treatment’s nature, purpose, and consequences, without requiring retention, weighing of information, or communication of a decision. It applies only to treatment decisions for detained patients under the MHA.
MCA 2005: The MCA provides a statutory definition of capacity in Section 3, requiring a person to:
- Understand the information relevant to the decision,
- Retain that information,
- Use or weigh it to make a decision, and
- Communicate their decision.
The above applies to all decisions (not just treatment) – except where another piece of law has priority – and is broader in scope, emphasising both cognitive processing (understanding, retaining, weighing) and communication.
Threshold for Capacity
- MHA 1983:
The threshold is binary: a person is either capable or incapable of understanding the treatment’s nature, purpose, and effects. There is no statutory requirement to assess retention, weighing in the balance, or communication. For example, a patient with schizophrenia refusing treatment due to delusions might lack capacity under the MHA if they cannot grasp the treatment’s purpose, even if they can communicate a decision . - MCA 2005:
Capacity is decision-specific and time-specific, requiring a holistic assessment of all four criteria. A person may lack capacity for one decision but retain it for others. For instance, a person with dementia might understand a treatment’s purpose (satisfying the MHA test) but fail to retain or weigh the information (failing the MCA test) .
Application Context
- MHA 1983: The capacity test applies largely to detained patients but some others receiving treatment for mental disorders under the CTOs. Under Section 58 (medication after 3 months) or Section 58A (ECT), the focus is on whether the patient can comprehend the treatment’s nature and effects, irrespective of their ability to weigh alternatives. The word ‘consent.
- MCA 2005: The test applies universally to all adults (unless otherwise specified) in any decision-making context, including medical treatment, financial matters, or care arrangements. It is not limited to mental health treatment .
Communication of Decisions
- MHA 1983:
The Act does not explicitly require an assessment of the patient’s ability to communicate their decision. The focus is solely on understanding. For example, a non-verbal patient who indicates consent through gestures might still be considered capable under the MHA if they understand the ‘nature, purpose and likely effects‘ of the treatment . - MCA 2005:
Communication is a core requirement. A person must be able to convey their decision through any means (e.g., speech, sign language, or assistive technology). Failure to communicate invalidates capacity under the MCA, even if the person internally understands the decision .
Legal Presumption of Capacity
- MHA 1983: There is no explicit presumption of capacity in the MHA. Capacity is assessed when compulsory treatment is proposed (or the three-month rule period has run out) in the context of detention.
- MCA 2005: Section 1(2) establishes a presumption of capacity unless proven otherwise. The burden lies on professionals to demonstrate incapacity using the Section 3 criteria .
Flexibility and Fluctuating Capacity
- MHA 1983: Capacity assessments under the MHA are generally snapshot evaluations at the time treatment is proposed. Fluctuating capacity (e.g., due to psychotic episodes) may lead to temporary incapacity, but the Act does not explicitly address this.
- MCA 2005: Explicitly recognises fluctuating capacity and requires decisions to be postponed where possible to allow capacity recovery. It also acknowledges partial capacity (e.g., a person may consent to day-to-day care but not complex surgery) .
MHACOP Guidance on Consent
The Mental Health Act Code of Practice (MHACOP) provides guidance on consent that aligns closely with the Mental Capacity Act 2005 (MCA), even though the MHA 1983 itself does not explicitly define capacity for consent to treatment. Let’s evaluate this in detail, considering the implications of the MHACOP guidance and its relationship with the MCA.
This analysis highlights the MHA’s narrower, treatment-specific approach compared to the MCA’s comprehensive, rights-based framework. The MHA’s reliance on understanding alone reflects its focus on enabling compulsory treatment, while the MCA conspicuously prioritises autonomy through a multi-faceted capacity assessment .
The MHACOP (at paragraphs 24.31 and 24.34) introduces a definition of consent, which closely mirrors the MCA’s principles. Specifically:
- 24.34 states that consent requires voluntary and continuing permission, based on sufficient knowledge of the treatment’s purpose, nature, likely effects, risks, success likelihood, and alternatives.
- 24.31 explicitly references the MCA’s definition of capacity for individuals aged 16 or over, effectively importing the MCA’s four-part test (understanding, retaining, weighing, and communicating) into the MHA framework.
This guidance suggests that, in practice, clinicians assessing capacity under the MHA should apply the MCA’s more rigorous standards, even though the MHA itself does not require this. Factually, Parliament has not referred to nor provided Mental Capacity Act (2005) considerations in any part of the MHA 1983 (Amended 2007). [Note that the MHA 1983 (Amended 2007) became law after Mental Capacity Act (2005)].
Relationship Between the MHA and MCA
- Statutory vs. Guidance:
The MHA is statutory law, while the MHACOP is guidance. This means that the MHACOP does not have the same legal force as the MHA or MCA. However, courts and tribunals often refer to the MHACOP as a benchmark for good practice, and failure to follow it may be cited in legal challenges. - Overlap and Tension:
The MHACOP bridges the gap between the MHA and MCA by aligning the definition of capacity for consent with the MCA. However, this creates a potential tension because the MHA itself does not explicitly require clinicians to assess capacity using the MCA’s criteria. For example, under the MHA, a patient might be deemed capable of consenting to treatment if they understand its nature and purpose, even if they cannot weigh the information or communicate a decision—a scenario that would fail the MCA’s test.
3. Practical Implications
- Clinicians’ Approach:
In practice, clinicians are likely to follow the MHACOP guidance, applying the MCA’s four-part test when assessing capacity for consent under the MHA. This ensures compliance with best practice and reduces the risk of legal challenges. - Legal Safeguards:
The MHACOP’s emphasis on voluntary and informed consent aligns with human rights principles (e.g., Article 8 of the European Convention on Human Rights). By referencing the MCA, the MHACOP strengthens safeguards for patients, particularly those with fluctuating or borderline capacity. - Exceptions:
The MHA allows for treatment without consent in certain circumstances (e.g., under Section 63 for treatment not requiring consent, or Section 58 for medication after 3 months). In these cases, the MHACOP’s guidance on consent may not apply, and the MHA’s narrower capacity test (understanding nature, purpose, and effects) may prevail.
4. Key Differences Despite Alignment
While the MHACOP aligns the MHA’s consent framework with the MCA, there are still key differences:
- Scope:
The MHA applies only to detained patients receiving treatment for mental disorders, whereas the MCA applies universally to all decisions for individuals aged 16 or over. - Legal Force:
The MCA’s definition of capacity is statutory and binding, while the MHACOP’s guidance is not. Clinicians must follow the MCA when assessing capacity outside the MHA context, but within the MHA, they have more flexibility. - Focus:
The MHA’s primary focus is on enabling treatment for mental disorders, even without consent in some cases. The MCA, by contrast, prioritises autonomy and decision-making capacity in all contexts.
5. Evaluation
The MHACOP’s guidance represents a practical harmonization of the MHA and MCA, ensuring that patients’ rights to informed consent are respected even within the MHA’s compulsory treatment framework. However, this alignment is not without challenges:
- Legal Ambiguity:
The MHACOP’s reliance on the MCA’s definition of capacity creates ambiguity because the MHA itself does not incorporate this definition. This could lead to inconsistencies in practice, particularly in cases where clinicians rely solely on the MHA’s narrower test. - Patient Safeguards:
The MHACOP’s approach strengthens safeguards for patients, ensuring that capacity assessments are thorough and consistent with human rights principles. However, this may also complicate decision-making for clinicians, particularly in urgent or complex cases. - Statutory Gap:
The MHA’s failure to explicitly define capacity for consent remains a significant gap, which the MHACOP attempts to fill. However, as guidance, it cannot fully resolve this statutory deficiency.
Way Point
The MHACOP’s guidance effectively imports the MCA’s definition of capacity into the MHA framework, aligning the two Acts in practice. However, this alignment is not statutory, and the MHA’s narrower approach to capacity remains legally distinct. The MHACOP’s emphasis on informed consent and voluntary permission reflects a rights-based approach, but its non-binding nature means that inconsistencies may arise in practice. For a more robust and coherent framework, statutory reform of the MHA to explicitly incorporate the MCA’s capacity test would be necessary.
ANALYSIS OF MHA BILL 2021 (CAPACITY/CONSENT)
This focuses on one particular aspect of the Bill – which is massive and convoluted.
Overview
The concept of capacity in the Mental Health Bill 2021 is not as clearly delineated as in the Mental Capacity Act 2005. While the bill does provide some guidance on assessing capacity and obtaining valid consent, it does not include a specific test for capacity like the one set out in the MCA. This part will not explore amendments to S57 because this article investigates the concepts of capacity and consent.
The Mental Health Bill 2021 includes several sections that address capacity and consent, such as Section 56A on making treatment decisions, Section 57 on treatment requiring consent and a second opinion, and Section 58 on treatment requiring consent or a second opinion. These sections require clinicians to consider a patient’s capacity to make decisions about their care and treatment, and to obtain valid consent from patients who have capacity. However, the bill does not provide a clear definition of what constitutes capacity, nor does it specify how capacity should be assessed.
Instead, MHA Bill proposed amendments rely on the clinical judgment of the responsible clinician to determine whether a patient has capacity to make a particular decision. In contrast, the Mental Capacity Act 2005 provides a more detailed framework for assessing capacity, including a two-stage test for determining whether a person lacks capacity to make a particular decision. The MCA also sets out a presumption of capacity, meaning that individuals are assumed to have capacity unless it is established otherwise.
Section 56A: Making Treatment Decisions -This section outlines the process for making treatment decisions for patients under the Act. It includes several key points related to capacity and consent:
Subsection (1)
- Identify and evaluate alternative treatments: The approved clinician must consider any available alternative forms of medical treatment.
- Encourage patient participation: Reasonable steps should be taken to assist and encourage the patient to participate in the decision-making process as fully as possible.
- Avoid unjustified assumptions: The clinician should not rely solely on the patient’s age, appearance, condition, or behavior when determining appropriate treatment.
- Consider past and present wishes: The clinician must take into account the patient’s past and present wishes, feelings, beliefs, and values, if reasonably ascertainable.
- Consult relevant views: The clinician should consider the views of anyone named by the patient, the patient’s nominated person, any independent mental health advocate, any donee or deputy, and any other person who cares for the patient or is interested in their welfare.
- Consider all circumstances: All other relevant circumstances known to the clinician should be considered.
Subsection (2)
Capacity considerations: If the patient lacks capacity in relation to matters relevant to the decision, the clinician must also consider what the patient would have wished if they had capacity, including any relevant written statements made by the patient when they had capacity.
While the Mental Health Bill 2021 does not provide as clear a definition of capacity as the MCA, it does aim to protect the rights and autonomy of people with mental health conditions by requiring clinicians to assess capacity and obtain valid consent before providing treatment. The bill also aligns with the principles of the MCA where applicable, particularly in relation to advance decisions, donees, and deputies.
Conclusions and takeaway points
The conceptualisation of capacity under the Mental Health Act 1983 and Mental Capacity Act 2005 represents two distinct approaches to understanding and assessing decision-making ability in mental health care. While the MHA adopts a focused view primarily concerned with treatment decisions, the MCA offers a broader framework emphasising autonomy across all decision-making contexts. This fundamental difference reflects their distinct purposes: the MHA’s emphasis on enabling necessary treatment versus the MCA’s focus on preserving individual autonomy wherever possible.
The Mental Health Act Code of Practice attempts to bridge these different approaches, though the statutory distinction remains. This creates a complex landscape for practitioners, who must navigate between these frameworks while maintaining clinical effectiveness and protecting patient rights. The proposed reforms in the Mental Health Bill 2021, while introducing new considerations around treatment decisions, maintain this distinction rather than fully reconciling these approaches.
Understanding these differences is not merely an academic exercise but reflects deeper questions about how we conceptualise capacity, consent, and autonomy in mental health care. As mental health law continues to evolve, these fundamental distinctions between the MHA and MCA approaches to capacity remain central to both clinical practice and the ongoing development of mental health law in the United Kingdom.