As I understand, “lucid interval” is a legal doctrine that holds that testamentary capacity may exist at a moment in time even though the testator’s general state would be inconsistent with the conclusion that he possessed testamentary capacity.[i] The idea is that an individual who suffers from mental illness or a neurological condition may have periods in which his or her ability to reason and make thoughtful choices is preserved.
The lucid interval has been defined broadly as a temporary cure or a temporary restoration to legal sanity. That is, an interval occurring in the mental life of a legally insane person during which he is completely restored to the use of his reason, or so far restored that he has sufficient intelligence, judgment, and will to enter into contractual relations, or perform other legal acts, without disqualification by reason of his disease. To establish the existence of a lucid interval it is not necessary to prove complete mental recovery. It is sufficient to show that the testator understands that he is making a testamentary disposition and what is required of him in making the disposition, and that any delusion from which he is still suffering does not affect such disposition.[ii]
However, it is questionable whether lucid intervals actually exist in individuals suffering from dementia. Recent research indicates that although these individuals may have some degree of fluctuation in their cognitive abilities, these fluctuations generally occur in respect of the person’s attention and alertness rather than in episodic memory and executive function – two qualities that are essential for testamentary capacity. As a consequence, the idea that a particular testator who generally lacks capacity may have executed estate planning documents during such an interval should be carefully scrutinized.[iii]
However, the concept of a lucid interval may be more applicable to cases of delirium. Delirium is characterized by fluctuating inattentiveness. Delirium does not necessarily lead to a lack of testamentary capacity in all cases. Theoretically, a person suffering delirium may be capable of signing a will during a lucid interval if his attentiveness and cognition has substantially improved and there is a clear rationale and consistency over time in the person’s expressed wishes.[iv] “Lucidity” is a relative concept relating to severity of the delirium at the time the will was made, and the issue is whether the testator, with his particular cognitive function and his particular situational complexity, could make this particular will at the relevant time.[v]
Therefore, under the doctrine of the lucid interval, the testimony of lay witnesses who observed the testator at the moment of the will execution may be preferred over the retrospective assessments of experts who were not present at the will’s execution. [vi] In a US case,[vii] a doctor’s opinion on medical incompetence was not given particular weight when other disinterested witnesses established that a person with Alzheimer’s disease was competent and not suffering from a weakened intellect at the relevant time. Similar Court opinion about lay testimony has been found in Ontario in the case of Dujardin v. Dujardin, where the Court (at paragraph 33 of its decision) quoted from Ian. M. Hull & Suzanna Popovic-Montag, Macdonnell, Sheard and Hull on Probate Practice, 5th ed. (Toronto: Thomson Reuters, 2016), whereby the authors observe, at p. 61, that the question of testamentary capacity “is a practical one that, so far as evidence based on observation is concerned, may be answered by laypersons of good sense as well as doctors.”
Nonetheless, in my humble and biased opinion, the evidence of lay witnesses should not be preferred to the evidence of expert testimony regarding the testamentary capacity of an individual, either contemporaneously or retrospectively. If doctors in hospitals routinely seek out the expertise of psychiatrists to understand the mental state of patients and to assist them to determine the decision-making capacity of patients in particularly challenging cases, then no doubt lawyers and the Court could benefit from that expertise
[i] See, for example, Skinner v Farquharson, 32 SCR 58, 1902 CanLII 87 (SCC)
[ii] Shulman, K. I., Hull, I. M., DeKoven, S., Amodeo, S., Mainland, B. J. & Herrmann, N. (2015). “Cognitive fluctuations and the lucid interval in dementia: Implications for testamentary capacity.” The Journal of the American Academy of Psychiatry and the Law, 43 (3), 287–92..
[iii] Shulman, K. I., Hull, I. M., DeKoven, S., Amodeo, S., Mainland, B. J. & Herrmann, N. (2015). “Cognitive fluctuations and the lucid interval in dementia: Implications for testamentary capacity.” The Journal of the American Academy of Psychiatry and the Law, 43 (3), 287–92.
[iv] Liptzin, B., Peisah, C., Shulman, K. and Finkel, S. (2010). “Testamentary capacity and delirium.” International Psychogeriatrics, 22, 950–956.
[v] Shulman KI, Peisah C, Jacoby R, Heinik J, Finkel S. (2009). “Contemporaneous assessment of testamentary capacity: a consensus report from the IPA Task Force on testamentary capacity and undue influence.” International Psychogeriatrics. Jun; 21(3):433-9.
[vi] In re Angle, 777 A.2d 114, 123 (Pa. Super. Ct. 2001)