The Mental Health Act and compulsory treatment — criteria, pathway and emergency sedation

(i) The criteria and their application. The criteria for involuntary detention under the Mental Health Act are four, and all four must be satisfied and documented. (1) A mental illness (or mental disorder) of a nature or degree that warrants treatment in hospital — this patient's relapsing schizophrenia with active delusions and command hallucinations meets this limb. (2) Detention is necessary for the person's health or safety (including serious self-neglect and deterioration) or for the protection of others — five days without food or sleep plus command hallucinations to jump from a bridge meet both the self-neglect and the suicide-risk limbs. (3) The person refuses or is unable to consent to voluntary admission — he refuses. (4) No less-restrictive option will achieve safe care — voluntary admission, community treatment and family support have been considered and will not contain the active command hallucinations and the starvation. All four limbs are met.^[2][4]

(ii) The statutory pathway. Detention follows a prescribed pathway documented on a statutory form — a schedule in much of Australasia, a section in the United Kingdom. Most jurisdictions require assessment by two authorised clinicians who each independently examine the patient and complete a statutory recommendation within the defined interval; one cannot merely countersign the other's assessment. As the emergency doctor I may be the first assessor; the second is typically a psychiatrist or a credentialed mental-health clinician. The completed schedule records the identity, the clinicians, the diagnosis, the criteria met and the proposed facility; it is signed, dated, served on the patient with a written statement of their rights in a form they understand, and a copy placed in the record. The assessment authority is short — a matter of days in most Australasian jurisdictions (the NSW Schedule 1 certificate for a mentally ill person; in the United Kingdom, Section 2 lasts 28 days) — and converts to a treatment order only after further assessment and, in many jurisdictions, a tribunal hearing.^[2]

(iii) Why capacity does not decide detention. Capacity and the Mental Health Act are distinct legal frameworks. Capacity is the cognitive and functional ability to make a specific decision, assessed by the four-stage test (understanding, retention, weighing, communicating) and presumed in every adult; it governs whether a patient may consent to or refuse any single decision, including psychiatric treatment. The Mental Health Act governs whether a person with a mental illness may be treated for that illness despite refusal, where the four statutory criteria are met. A patient may have full capacity to refuse admission and still be lawfully detained; conversely, a patient may lack capacity entirely through delirium and yet not meet the criteria, because delirium is a medical illness treated under the doctrine of necessity, not under the Act. The candidate who refuses to detain because the patient "has capacity" has conflated two statutes and left a dangerous illness untreated.^[4]

(iv) Pharmacological management of the dangerous detained patient. The legal authority to treat now exists under the Act, but treatment is delivered by the least restrictive effective means. Verbal de-escalation is attempted first in a calm, low-stimulation area with sufficient trained staff, with the offer of oral medication. If he remains an imminent danger and refuses, rapid tranquillisation is given intramuscularly: droperidol 5 to 10 mg intramuscularly is first-line for undifferentiated severe agitation, with ECG monitoring for QT prolongation; for a primarily psychotic picture, haloperidol 5 mg intramuscularly, often with promethazine 25 to 50 mg intramuscularly, is the alternative. I would avoid combining intramuscular olanzapine with a parenteral benzodiazepine because of the additive risk of respiratory depression. Monitoring is mandatory throughout — continuous pulse oximetry, blood pressure, respiratory rate and level of consciousness, with a periodic ECG after any dopamine antagonist — and formal reassessment every 10 to 15 minutes until the patient is calm and rousable, never unconscious. Airway equipment, flumazenil and naloxone are immediately available. The indication, the agent, the dose and the monitoring are documented.^[5]

(v) Rights of review and appeal. At the point of detention the patient is given a written statement of his rights in a form he can understand, and these are recorded. He has the right to information about the detention and treatment; the right to legal representation and to an advocate (an Independent Mental Health Advocate in the United Kingdom); the right to apply to the Mental Health Tribunal for discharge, with the hearing held within a statutory time; the right to a second psychiatric opinion on the appropriateness of treatment; and the right to make a complaint. The tribunal — a Mental Health Review Tribunal, a Mental Health Review Board, or a court — hears the case at defined intervals and decides whether to discharge, vary or continue the order. Exceeding the statutory time limit without renewal, or omitting the tribunal review, makes the continued detention unlawful.^[3]