Mental illness – consent – capacity – incapacity – medical treatment – refusal
In determining whether a person had sufficient capacity to refuse treatment, the question to be decided was whether it had been established that his capacity had been so reduced by his chronic mental illness that he did not sufficiently understand the nature, purpose and effects of the proffered medical treatment. That in turn depended on whether he had comprehended and retained information as to the proposed treatment, had believed it and had weighed it in the balance when making a choice.
In this case, the patient, who suffered from paranoid schizophrenia, had developed gangrene whilst in prison. He was diagnosed as likely to die imminently if the leg was not amputated below the knee, with only a 15% chance of survival without amputation. C repeatedly refused to consent to the amputation and sought an injunction restraining the hospital from amputating without his express consent. The hospital contended that C’s capacity to give a definitive decision had been impaired by his mental illness and that he had failed to appreciate the risk of death if the operation was not performed.
The court, however, found that although C’s general capacity to make a decision had been impaired by schizophrenia, the evidence failed to establish that he lacked sufficient understanding of the nature, purpose and effects of the proposed treatment, but instead showed that he had understood and retained the relevant treatment information, believed it and had arrived at a clear choice. It followed that the presumption in favour of his right to self-determination had not been displaced, and a declaration that C was capable of giving or refusing consent was made.