Residual liberty and the detained mental health patient

The purpose of the Mental Health Act 1983 is to make provision for the detention and compulsory treatment of a person's mental disorder where they are objecting to that admission or treatment (Tameside & Glossop Acute Services NHS Trust v CH [1996]).

Compulsory treatment of a detained patient under Part 4 of the Act has long adopted a ‘treatment as a whole’ approach that allows for the physical manifestations of a mental disorder to be treated under the compulsory provisions. In B v Croydon Health Authority [1995], the court held that tube-feeding a detained patient with a personality disorder who self-harmed by starving was treatment for a mental disorder that could be administered lawfully without the patient's consent.

The treatment as a whole approach does not include treatment for a physical condition unrelated to a person's mental disorder. In St George's Healthcare NHS Trust v S [1998] the Court of Appeal declared that detaining a woman under the 1983 Act in order to dispense with her refusal to consent to treatment for pre-eclampsia was unlawful. A person detained under the Act retained the right to withhold consent to medical procedures unrelated to their mental disorder.