Assessing the ability of people with a learning disability to give informed consent to treatment

Psychol Med. 1999 Nov;29(6):1367-75. doi: 10.1017/s0033291799008715.


Background: People with a learning disability are increasingly being encouraged to take a more active role in decisions about their psychological and medical treatment, raising complex questions concerning their ability to consent. This study investigates the capacity of people with a learning disability to consent in the context of three treatment vignettes, and the influence of verbal and memory ability on this capacity.

Methods: Measures of verbal ability, memory ability and ability to consent to treatment (ACQ) were administered to 40 people with a learning disability. The ACQ consisted of three vignettes depicting a restraint, psychiatric or surgical intervention. These were followed by questions addressing people's ability to understand the presenting problem; the nature of the proposed intervention; the alternatives, risks and benefits; their involvement in the decision-making process; and their ability to express a clear decision with a rationale for treatment.

Results: Five people (12.5%) could be construed as able to consent to all three vignettes; 26 (65%) could be construed as able to consent to at least one. The questions that were most difficult to answer concerned a participants' rights, options and the impact of their choices. Verbal and memory ability both influenced ability to consent.

Conclusions: This study introduces a measure that may enable clinicians to make more systematic assessments of people's capacity to consent. A number of issues surrounding the complex area of consent to treatment are also raised.

MeSH terms

  • Adult
  • Female
  • Humans
  • Informed Consent / legislation & jurisprudence*
  • Learning Disabilities / psychology*
  • Male
  • Mental Competency / legislation & jurisprudence*
  • Middle Aged
  • Neuropsychological Tests
  • United Kingdom