“…the wording of s.2(1) itself does not require a formal diagnosis before the court can be satisfied that whether any inability of R to make a decision in relation to the matter in issue is because of an impairment of, or a disturbance, in the functioning of the mind or brain. The words “impairment of, or a disturbance in” are not further defined elsewhere in the Act. In these circumstances, there is no basis for interpreting the statutory language as requiring the words “impairment of, or disturbance in” to be tied to a specific diagnosis. Indeed, it would be undesirable to do so. To introduce such a requirement would constrain the application of the Act to an undesirable degree, having regard to the complexity of the mind and brain, to the range of factors that may act to impair their functioning and, most importantly, to the intricacies of the causal nexus between a lack of ability to take a decision and the impairment in question. In PC v City of York Council McFarlane LJ (as he then was) cautioned against using s.2(1) as a means “simply to collect the mental health element” of the test for capacity and thereby risk a loss or prominence of the requirement of a causative nexus created by the words “because of” in s.2(1). Reading s.2(1) as requiring a formal diagnosis would in my judgment significantly increase that risk.”
“This is reflected in the fact that of the just over 2.5 per cent (approximately) of the population whose IQs are believed to be under 70, just a quarter to a third are known to Intellectual Disability Services; this implies that many people with this level of cognitive ability are nevertheless able to function adequately in their everyday lives and so do not fulfil the criterion of a ‘significant impairment of adaptive behaviour’. Conversely, there are many people whose adaptive behaviour is impaired but whose IQs are above 70, who are known to services as ‘vulnerable adults’, and who fulfil the criteria for certain other conditions, such as autistic spectrum disorder, personality disorder, etc. (It is generally true that people who are referred to services have deficits in their adaptive behaviour; indeed this usually is the reason why they need help and are referred in the first place.)”
“The fact that he can learn computer skills, adapt his signing to meet my needs, understand humour and answer questions involving ‘why?’, all support the notion that he does not have a learning disability. However, there are clear deficits in understanding of more abstract and complex matters and impairments in adaptive functioning, most notably a lack of insight into his own needs and matters concerning risk.”
“1 The principles … (2) A person must be assumed to have capacity unless it is established that he lacks capacity. (3) A person is not to be treated as unable to make a decision unless all practicable steps to help him to do so have been taken without success. (4) A person is not to be treated as unable to make a decision merely because he makes an unwise decision. … 2 People who lack capacity (1) For the purposes of this Act, a person lacks capacity in relation to a matter if at the material time he is unable to make a decision for himself in relation to the matter because of an impairment of, or a disturbance in the functioning of, the mind or brain. (2) It does not matter whether the impairment or disturbance is permanent or temporary. (3) A lack of capacity cannot be established merely by reference to— (a) a person's age or appearance, or (b) a condition of his, or an aspect of his behaviour, which might lead others to make unjustified assumptions about his capacity. (4) In proceedings under this Act or any other enactment, any question whether a person lacks capacity within the meaning of this Act must be decided on the balance of probabilities. … 3 Inability to make decisions (1) For the purposes of section 2, a person is unable to make a decision for himself if he 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 his decision (whether by talking, using sign language or any other means). (2) A person is not to be regarded as unable to understand the information relevant to a decision if he is able to understand an explanation of it given to him in a way that is appropriate to his circumstances (using simple language, visual aids or any other means). (3) The fact that a person is able to retain the information relevant to a decision for a short period only does not prevent him from being regarded as able to make the decision. (4) The information relevant to a decision includes information about the reasonably foreseeable consequences of— (a) deciding one way or another, or (b) failing to make the decision.” (a) a person's age or appearance, or (b) a condition of his, or an aspect of his behaviour, which might lead others to make unjustified assumptions about his capacity. (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 his decision (whether by talking, using sign language or any other means). (a) deciding one way or another, or (b) failing to make the decision.”
“The core determinative provision within the statutory scheme for the assessment of whether P lacks capacity is section 2(1). The remaining provisions of sections 2 and 3, including the specific elements within the decision-making process set out in section 3(1), are statutory descriptions and explanations which support the core provision in section 2(1). Those additional provisions do not establish a series of additional, freestanding tests of capacity. Section 2(1) is the single test, albeit that it falls to be interpreted by applying the more detailed description given around it in sections 2 and 3: see the judgment of McFarlane LJ in York City Council v C at paras 56 and 58-60.”