Mental health law

During your time at medical school, you will be exposed to the fact that the medical profession does not operate in a vacuum. Instead there are numerous interfaces with many different organisations, ranging from social care to the police and indeed a prominent medico-legal interface. This will be especially relevant in your time during your psychiatry placement where the rightfully rigid rules surrounding deprivation of liberty and safeguarding for both patient’s own well-being as well as others are made clear.

However, these issues will not just be restricted to the psychiatric setting, dealing with capacity and ensuring that the patient is able to make decisions about their care can crop up in any setting. When you are a junior doctor late at night dealing with a delirious patient, how will you assess their capacity and autonomy? These present both ethical and procedural questions about how to make a judgment with the patient’s best interest in mind and so in this section we will cover some of the legal requirements as well as the frameworks for assessing capacity. A patient lacking capacity may be an issue or ethical case brought up at interview but as you progress through medical school and see situations where such judgments apply, you can think of how you would respond and reflect on the issues at play.

Mental Health Law

The Mental Health Act

Enacted into law in 1983 (and further amended in 2007 & 2012), this applies to people in England and Wales with a “mental disorder”. This act contains the necessary provisions to detain and treat those people without their consent. This is only acceptable on the basis that the person poses a risk to their own health or safety or that of others. This particularly applies to patients in the midst of a psychotic episode and allows for detention by the police, nurses and doctors both in the short and long term for treatment. Lengthier detentions will require the approval of a second ‘approved mental health professional’ who is unconnected with the case in order to neutrally determine such a restriction to a patient’s liberty.

There are several sections of the law which can be used to detain patients:

  • Section 5(2) – This can be done as a FY1 and allows for 72 hours of detention for assessment only. The individual being sectioned has to be an inpatient/on the wards. The section does not count if in A&E or in an Acute Assessment Unit, they must be admitted patient on ward under consultant. The patient must be assessed within 72 hours by a psychiatrist to progress on to Section 2/3. Simply stating you’ve sectioned a patient counts under the law. Can sedate patients for safety in the immediate moment.
  • Section 2 – Compulsory admission to psychiatric facility for assessment for up to 28 days. Requires 2 approved mental health professionals (AMHP)
  • Section 3 – Compulsory treatment of mental disorder at a psychiatric facility for up to 6 months. Requires 2 approved mental health professionals (AMHP)
  • Section 136 – section is for use by police officers that are believed to be dealing with patient with mental disorder in public that believe that they believe requires psych treatment

The Mental Capacity Act

Set out in 2005, this addresses the legal mechanisms of making decisions for a patient (older than 16) who may lack capacity. A patient’s capacity can be altered by a number of medical conditions, ranging from transient such as delirium on a background of infection to more permanent such as a brain injury or dementia. In order to have capacity to make a decision, a patient must be able to:

  1. Understand information given pertaining to the decision
  2. Retain the information given
  3. Weigh up and use the information to make a decision
  4. Be able to communicate their decision

A patient can only be said to have capacity if they satisfy all 4 criteria, otherwise they lack the capacity to make decisions about their treatment. As stated previously, this can be a temporary or permanent phenomenon and it is important to regularly re-evaluate a patient’s capacity in order to ensure you are not infringing on patient autonomy while they do have capacity.

While the MHA only contains provision to detain and provide treatment for the condition which the patient has been detained, the Mental Capacity Act provides more leeway in treatment. In the previously mentioned case of a patient with delirium, this would allow healthcare providers to treat the underlying cause (e.g. a urinary tract infection or sepsis) rather than just addressing the confusion and mental state changes.

Such a power to treat, possibly against the patients wishes (while incapable) requires safeguards. The law itself states that any treatment provided must be in their best interests. The healthcare provider who has been providing treatment is normally responsible for this decision but they must work through a set process with checklists that are included in the Mental Capacity Act.

It is also worth noting that even if a patient is judged to be incapable of making a decision, this does not necessarily give the doctor the go ahead to begin treatment based on the patient’s best interest in their judgement. Patients may make an advance decision while capable to refuse or withdraw consent from any future interventions. These advance decisions normally are recorded in the patient notes, either in the form or written document and while not legally binding, these requests or wishes should be taken into account when the treatment provider is making decisions on the patient’s behalf. Patient’s may also nominate an advocate to make decisions for them, whether a family member or a lawyer and so before moving ahead with any treatment plan, it is essential to ensure that a step hasn’t been missed or that any nominated advocate has been part of the process.

Even if an advocate has not been nominated, all local authorities have a statuary duty to provide a service of an Independent Mental Capacity Advocate (IMCA) or in the case of the Mental Health Act, an Independent Mental Health Advocate (IMHA). These again provide another safeguard for patients wellbeing and represent the patient’s interests when decisions are being made about them and their treatment or their liberty. This is vitally important for patients who may not have family available or are isolated and who are likely to bee the most vulnerable service users.

The Mental Capacity Act, like the Mental Health Act contains pro visions to detain someone if this would be judged to be in their best interests (see box for conditions covered below). An example of this might be a delirious patient on the ward who is confused by their surroundings and attempts to wander off. In their state, they may pose a risk to themselves and may need to be detained in order for treatment to be provided. In the Mental Capacity Act, any such detentions must be carried out under the ‘deprivation of liberty safeguards’ process whereby 2 different professionals must agree that the patient both lacks capacity and that depriving the patient of their freedom is in their best interest. In recent years, this process has mostly been used to detain patients with dementia. It is worth noting that it would be inappropriate to detain a patient with a mental health disorder such as psychosis with this. There are clear processes outlined in the Mental Health Act for such patients.

Summary of MCA

  • Legislates for treatment of patients over the age of 16 who were believed to lack capacity
    • Under 16 – Gillick competent? (see section on consent for more information)
  • Act allows compulsory and (if necessary) restrained treatment of any physical condition without consent, if believed to be in the patient’s best interest
  • Capacity = understand/retain (even if its only for 1 minute)/consider/communicate
  • Each decision is decision specific – if no capacity to determine where to live, does not give you free reign to give antibiotics next day – each needs to be capacity determined via DOLS (deprivation of liberty safeguard)

Categories of Mental Disorder

  1. Affective disorders, such as depression and bipolar disorder
  2. Schizophrenia and delusional disorders
  3. Neurotic disorders, such as anxiety, phobias, obsessive-compulsive disorders, post-traumatic stress disorder and hypochondriacism
  4. Organic disorders, such as dementia
  5. Personality disorders (may or may not) be caused by brain injury
  6. Mental and behavioural disorders caused by psycho-active substance use
  7. Eating disorders, non-organic sleep disorders, non-organic sexual disorders
  8. Autistic spectrum disorders
  9. Behavioural and emotional disorders of children and adolescents

n.b. Learning disability and drug/alcohol misuse were removed in an update of the MHA in 2007

Criticisms of the Law

While this sounds reasonable in practice, its application has been somewhat varied with a report issued in 2014 by the House of Lords 1 finding that many professionals are not using the Act appropriately, often failing to carry out capacity assessments. The committee advised that an independent body may need to be established to advise and make health professionals aware of the role of the act.

Deprivation of Liberty safeguards were also criticised as being poorly understood and overly complicated and also recommending that this system be changed. Following government guidance issued later in 2014, the government has recommended making improvements to the safeguards process as well as creating a new Mental Capacity Advisory Board to promote awareness of the system. The proposals are due for presentation and drafting by 2017 and this may well be an area of medical practice that will evolve during your time at medical school. Nevertheless, being aware of the current system and the challenges that exist within its rollout will be valuable both to apply to your early years of practice as well as colouring your interpretation and understanding of any new processes or systems that come about.

Furthermore, as the law evolves so does the expected standard of practice and this is set out in regularly issued codes of practise (which exist for both the Mental Health Act and the Mental Capacity Act.) All mental health professionals must be aware and acknowledge them when making decisions and this may be worth study if this is a field that particularly interests you or if you just wish to find out more about the challenging nature of decisions in this arena.


  • Any decision to go against a patient’s autonomy or deprive them of their liberty is an extremely serious matter and must only be done if absolutely necessary
  • Capacity consists of 4 principles – to understand, retain, weigh up and communicate their decision
  • If a patient is judged to be incapable, this must be regularly reviewed to ensure that the patient is not being treated and their autonomy violated while capable.
  • The Mental Health Act and Mental Capacity Act provide doctors with the ability to treat patients against their wishes but this must always be done with the patient’s best interests in mind
  • There are clearly defined processes and checklists that must be applied when taking any decision to deprive a patient of their liberty
  • Although not legally binding, any input in the form of a written advance directive, a nominated advocate or an independent advocate from the local health authority must be weighed up carefully as part of the decision making process
  • The law as it stands may be poorly recognised with overly complex procedures and this is likely to change in the near future with the establishment of new independent bodies to provide oversight and promote awareness.


1 Mental Capacity Act 2005: post-legislative scrutiny. Select Committee on the Mental Capacity Act 2005. House of Lords. Report of Session 2013-14

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