The High Court has ruled on the capacity of a vulnerable adult, T, to decide on two issues: where she should live, or whether she should have contact with family members. The case, RT and LT v A Local Authority was complex. Persons with T's IQ would normally have capacity to decide on such issues. T had only a mild learning disability but a significant disorder of social functioning and interaction. While she could discuss relevant issues, she had very fixed views on certain matters. An expert jointly instructed by the parties described how T was only able to identify the arguments on one side of these issues, trying to get her to discuss contrary arguments was "the wall through which you could not pass".

The court emphasised that the "individual capacities" set out in section 3(1) of the Act are not cumulative. An individual lacks capacity if any of paragraphs (a) to (d) apply, ie, that the person is unable:

(a)      to understand the information relevant to the decision;

(b)      to retain that information;

(c)      to use or weigh that information as part of the process of making the decision; or

(d)      to communicate that decision (whether by talking, using sign language or any other means).

The court accepted the expert's evidence that T fell under paragraph (c), and ruled that she lacked capacity to decide on the issues of residence and family contact.

In a postscript to the judgment, the court stressed that, where possible, the plain words of the Act should be applied to all cases. Trawling through old case law to interpret the statute will usually not be helpful.