Intended for healthcare professionals

Letters Mental Capacity Act

How research is affected

BMJ 2008; 336 doi: (Published 21 February 2008) Cite this as: BMJ 2008;336:405
  1. Andrew J Ludman, cardiology research fellow
  1. 1Hatter Cardiovascular Institute, University College London, London WC1E 6HX
  1. a.ludman{at}

The Mental Capacity Act 2005 could be regarded as protective to both patient and clinician in the circumstances of routine medical care.1 It has also helped clarify the issue of capacity when patients are asked to take part in research studies. Sections 30-34 of the act deal very well with issues of diminished capacity and enrolment to clinical studies.2 Far from being too restrictive to those wishing to study groups of patients with diminished capacity, the act is supportive, as long as the patient group being studied must necessarily be recruited at a time when capacity is diminished and time is of the essence—for example, studies in acute myocardial infarction.

Section 31, paragraph 5a, highlights that the research study must have the potential to benefit the patient without imposing on the patient a burden that is disproportionate to the potential benefit to him or her.

For researchers it is important to note that the act does not apply necessarily to trials which fall under the Medicines for Human Use Regulations 2004, as separate legislation and guidance exists.

Researchers must work closely with their local ethics committee to ensure that the consent process is appropriate to the situation, and that the stipulations of the act are followed. It is also important to realise that research in patient groups with diminished capacity is essential in some circumstances and that the Mental Capacity Act 2005 clearly allows for this.


  • Competing interests: None declared.


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