Current Neurology and Neuroscience Reports

, Volume 10, Issue 5, pp 367–373

Consent in Impaired Populations



Impairments in patients with dementia and other disorders affecting cognition may have a negative impact on their capacity to provide consent to treatment or to participation in research. A growing literature confirms that even patients with mild cognitive impairment may experience decrements in decisional abilities, findings that are more pronounced still in the early stages of dementia. However, most patients with mild dementia probably remain competent to provide a valid consent to treatment or research, and even some patients with moderate dementia may retain capacity in particular circumstances. Clinical evaluation of decisional competence has been augmented by structured approaches, including reliable instruments that may be used in the clinical setting. To avoid needlessly depriving patients of their right to make health care decisions, evaluations should be designed to maximize patient performance. However, when substitute consent is necessary, state laws generally provide a range of options, including advance directives and familial consent.


Informed consent Competence Decisional capacity Treatment Research Assessment Dementia Mild cognitive impairment Surrogate consent 


Papers of particular interest, published recently, have been highlighted as: • Of importance

  1. 1.
    Berg JW, Appelbaum PS, Lidz CW, Parker L: Informed Consent: Legal Theory and Clinical Practice. edn 2. New York: Oxford University Press; 2001.Google Scholar
  2. 2.
    Kim SYH, Karlawish JHT, Caine ED: Current state of research on decision-making competence of cognitively impaired elderly persons. Am J Geriatr Psychiatry 2002, 10:151–165.PubMedGoogle Scholar
  3. 3.
    • Appelbaum PS: Assessment of patients’ competence to consent to treatment. N Engl J Med 2007, 357:1834–1840. This is a useful overview of issues related to the definition and assessment of competence, including suggested questions to guide assessment.CrossRefPubMedGoogle Scholar
  4. 4.
    Marson DC, McInturff B, Hawkins L, et al.: Consistency of physician judgments of capacity to consent in mild Alzheimer’s disease. J Am Geriatr Soc 1997, 45:453–457.PubMedGoogle Scholar
  5. 5.
    Marson DC, Earnst KS, Jamil F, et al.: Consistency of physicians’ legal standards and personal judgments of competency in patients with Alzheimer’s disease. J Am Geriatr Soc 2000, 48:911–918.PubMedGoogle Scholar
  6. 6.
    Dunn LB, Mowrangi MA, Palmer BW, et al.: Assessing decisional capacity for clinical research or treatment: a review of instruments. Am J Psychiatry 2006, 163:1323–1334.CrossRefPubMedGoogle Scholar
  7. 7.
    Karlawish JHT, Casarett DJ, James BD, et al.: The ability of persons with Alzheimer Disease (AD) to make a decision about taking an AD treatment. Neurology 2005, 64:1514–1519.CrossRefPubMedGoogle Scholar
  8. 8.
    Grisso T, Appelbaum PS: MacArthur Competence Assessment Tool for Treatment (MacCAT-T). Sarasota, FL: Professional Resource Press; 1998.Google Scholar
  9. 9.
    Lui VWC, Lam LCW, Luk DNY, et al.: Capacity to make treatment decisions in Chinese older persons with very mild dementia and mild Alzheimer’s disease. Am J Geriatr Psychiatry 2009, 17:428–436.CrossRefPubMedGoogle Scholar
  10. 10.
    Moye J, Karel MJ, Azar AR, Gurrera RJ: Capacity to consent to treatment: empirical comparison of three instruments in older adults with and without dementia. Gerontologist 2004, 44:166–175.PubMedGoogle Scholar
  11. 11.
    Petersen RC, Doody R, Kurz A, et al.: Current concepts in mild cognitive impairment. Arch Neurology 2001, 58:1985–1992.CrossRefGoogle Scholar
  12. 12.
    Okonkwo O, Griffith HR, Belue K, et al.: Medical decision-making capacity in patients with mild cognitive impairment. Neurology 2007, 69:1528–1535.CrossRefPubMedGoogle Scholar
  13. 13.
    Marson DC, Ingram K, Cody H, Harrell LE: Assessing the competency of patients with Alzheimer’s disease under different legal standards. Arch Neurology 1995, 52:949–954.Google Scholar
  14. 14.
    Okonkwo OC, Griffith HR, Copeland JN, et al.: Medical decision-making capacity in mild cognitive impairment: a 3-year longitudinal study. Neurology 2008, 71:1474–1480.CrossRefPubMedGoogle Scholar
  15. 15.
    Huthwaite JS, Martin RC, Griffith HR, et al.: Declining medical decision-making capacity in mild AD: a two-year longitudinal study. Behav Sci Law 2006, 24:453–464.CrossRefPubMedGoogle Scholar
  16. 16.
    Moye J, Karel MJ, Gurrera RJ, Azar AR. Neuropsychological predictors of decision-making capacity over 9 months in mild-to-moderate dementia. J Gen Intern Med 2006, 21:78–83.CrossRefPubMedGoogle Scholar
  17. 17.
    Vollmann J, Bauer A, Hoipfe HD, Helmchen H: Competence of mentally ill patients: a comparative empirical study. Psychol Med 2003, 33:1463–1471.CrossRefPubMedGoogle Scholar
  18. 18.
    Maxmin K, Cooper C, Potter L, Livingston G: Mental capacity to consent to treatment and admission decisions in older adult psychiatric inpatients. Int J Geriatr Psychiatry 2009, 24:1367–1375.CrossRefPubMedGoogle Scholar
  19. 19.
    Gurrera RJ, Moye J, Karel MJ, et al.: Cognitive performance predicts treatment decisional abilities in mild to moderate dementia. Neurology 2006, 66:1367–1372.CrossRefPubMedGoogle Scholar
  20. 20.
    Palmer BW, Jeste DV: Relationship of individual cognitive abilities to specific components of decisional capacity among middle-aged and older patients with schizophrenia. Schizophr Bull 2006, 32:98–106.CrossRefPubMedGoogle Scholar
  21. 21.
    Marson DC, Chatterjee A, Ingram KK, Harrell LE: Toward a neurologic model of competency: cognitive predictors of capacity to consent in Alzheimer’s disease using three different legal standards. Neurology 1996, 46:666–672.PubMedGoogle Scholar
  22. 22.
    Dymek MP, Atchison P, Harrell L, Marson DC: Competency to consent to medical treatment in cognitively impaired patients with Parkinson’s disease. Neurology 2001, 56:17–24.PubMedGoogle Scholar
  23. 23.
    Appelbaum PS, Grisso T: The MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR). Sarasota, FL: Professional Resource Press; 2001.Google Scholar
  24. 24.
    Black BS, Brandt J, Rabins PV, et al.: Predictors of providing informed consent or assent for research participation in assisted living residents. Am J Geriatr Psychiatry 2008, 16:83–91.CrossRefPubMedGoogle Scholar
  25. 25.
    Warner J, McCarney R, Griffin M, et al.: Participation in dementia research: rates and correlates of capacity to give informed consent. J Med Ethics 2008, 34:167–170.CrossRefPubMedGoogle Scholar
  26. 26.
    Buckles VD, Powlishta KK, Palmer JL, et al.: Understanding of informed consent by demented individuals. Neurology 2003, 61:1662–1666.PubMedGoogle Scholar
  27. 27.
    Karlawish J, Kim SYH, Knopman D, et al.: Interpreting the clinical significance of capacity scores for informed consent in Alzheimer disease clinical trials. Am J Geriatr Psychiatry 2008, 16:568–574.CrossRefPubMedGoogle Scholar
  28. 28.
    Karlawish JHT, Casarett DJ, James BD: Alzheimer’s disease patients’ and caregivers’ capacity, competency, and reasons to enroll in an early-phase Alzheimer’s disease clinical trial. J Am Geriatr Soc 2002, 50:2019–2024.CrossRefPubMedGoogle Scholar
  29. 29.
    Kim SYH, Cox C, Caine ED: Impaired decision-making ability in subjects with Alzheimer’s disease and willingness to participate in research. Am J Psychiatry 2002, 159:797–802.CrossRefPubMedGoogle Scholar
  30. 30.
    Jefferson AL, Lambe S, Moser DJ, et al.: Decisional capacity for research participation in individuals with mild cognitive impairment. J Am Geriatr Soc 2008, 56:1236–1243.CrossRefPubMedGoogle Scholar
  31. 31.
    Schillerstrom JE, Rickenbacker D, Joshi KG, Royall DR: Executive function and capacity to consent to a noninvasive research protocol. Am J Geriatr Psychiatry 2007, 15:159–162.CrossRefPubMedGoogle Scholar
  32. 32.
    Palmer BW, Dunn LB, Appelbaum PS, et al.: Assessment of capacity to consent to research among older persons with schizophrenia, Alzheimer disease, or diabetes mellitus. Arch Gen Psychiatry 2005, 62:726–733.CrossRefPubMedGoogle Scholar
  33. 33.
    Griffith HR, Belue K, Sicola A, et al.: Impaired financial abilities in mild cognitive impairment: a direct assessment approach. Neurology 2003, 60:449–457.PubMedGoogle Scholar
  34. 34.
    Triebel KL, Martin R, Griffith HR, et al.: Declining financial capacity in mild cognitive impairment: a 1-year longitudinal study. Neurology 2009, 73:928–934.CrossRefPubMedGoogle Scholar
  35. 35.
    Allen RS, DeLaine SR, Chaplin WF, et al.: Advance care planning in nursing homes: correlates of capacity and possession of advance directives. Gerontologist 2003, 43:309–317.PubMedGoogle Scholar
  36. 36.
    Lai JM, Gill TM, Cooney LM, et al.: Everyday decision-making ability in older persons with cognitive impairment. Am J Geriatr Psychiatry 2008, 16:693–696.CrossRefPubMedGoogle Scholar
  37. 37.
    Appelbaum PS, Bonnie R, Karlawish J: The capacity to vote of persons with Alzheimer’s disease. Am J Psychiatry 2005, 162:2094–2100.CrossRefPubMedGoogle Scholar
  38. 38.
    Raymont V, Bingley W, Buchanan A, et al.: The prevalence and associations of mental incapacity in medical inpatients. Lancet 2004, 364:1421–1427.CrossRefPubMedGoogle Scholar
  39. 39.
    Kim SYH, Caine ED: Utility and limits of the Mini Mental State Examination in evaluating consent capacity in Alzheimer’s disease. Psychiatr Serv 2002, 53:1322–1324.CrossRefPubMedGoogle Scholar
  40. 40.
    Etchells E, Darzins P, Silberfeld M, et al.: Assessment of patient capacity to consent to treatment. J Gen Intern Med 1999, 14:27–34.CrossRefPubMedGoogle Scholar
  41. 41.
    Grisso T, Appelbaum PS: Assessing Competence to Consent to Treatment: A Guide for Physicians and Other Health Professionals. New York: Oxford University Press; 1998.Google Scholar
  42. 42.
    Dunn LB, Jeste DV: Enhancing informed consent for research and treatment. Neuropsychopharmacol 2001, 24:595–607.CrossRefGoogle Scholar
  43. 43.
    • Mittal D, Palmer D, Dunn L, et al.: Comparison of two enhanced consent procedures for patients with mild Alzheimer disease or mild cognitive impairment. Am J Geriatr Psychiatry 2007, 15:163–167. This is the only study to date demonstrating the utility of enhanced consent for improving decisional capacity among patients with MCI or AD.CrossRefPubMedGoogle Scholar
  44. 44.
    Resnick HE, Schuur JD, Heineman J, et al.: Advance directives in nursing home residents aged greater than or equal to 65 years: United States 2004. Am J Hosp Palliat Care 2009, 25:476–482.CrossRefGoogle Scholar
  45. 45.
    Commission on Law and Aging, American Bar Association: Default surrogate consent statutes, November 2009. Available at Accessed December 2009.
  46. 46.
    Kim SYH, Appelbaum PS, Jeste DV, Olin J: Proxy and surrogate consent in geriatric neuropsychiatric research: update and recommendations. Am J Psychiatry 2004, 161:797–806.CrossRefPubMedGoogle Scholar
  47. 47.
    • Saks ER, Dunn LB, Wimer J, et al.: Proxy consent to research: the legal landscape. Yale J Health Policy Law Ethics 2008, 8:37–92. This is a definitive review of the state of the law on proxy consent to research.PubMedGoogle Scholar
  48. 48.
    Office of Human Research Protections, US Department of Health and Human Services: Informed Consent—Frequently Asked Questions. Available at Accessed December 2009.
  49. 49.
    Kim SYH, Kim HM, Langa KM, et al.: Surrogate consent for dementia research: a national survey of older Americans. Neurology 2009, 72:149–155.CrossRefPubMedGoogle Scholar
  50. 50.
    Stroup S, Appelbaum P: The subject advocate: protecting the interests of participants with fluctuating decision making capacity. IRB 2003, 25(3):9–11.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.New York State Psychiatric InstituteNew YorkUSA

Personalised recommendations