Does old age render you incompetent? Incompetent elders have started showing up in increasing numbers, in both civil (testamentary/contractual competency, guardianship proceedings) and criminal arenas (competency to stand trial). We have adopted what we consider a powerful new assessment approach to forensic neurocognitive assessments based on Pearson’s WAIS-IV-WMS-IV-ACS combo and started looking at the data. Table A.2 and Ch 6 of the WAIS-IV technical manual address the very interesting developmental trajectories of the traditional “hold vs. don’t hold” WAIS subtests as your brain wears out. Reading/verbal skills are the last to go.
In recently examining an 81-year old defendant, we found that his WAIS-IV indices were in the low average range based on normative comparisons to his WAIS-IV age group (80:00-84:11), but when compared to 40 somethings or the 20:00-34:11 reference group that has been there since the WAIS and WAIS-R, his performance falls into the mentally deficient range. Thus, compared to the typical younger defendant, the old fellow, although not too far off for his age gropup, is likely to be incompetent to stand trial. There is not much in the lit on this. Frierson, 2002, is limited but points in the right direction. They do note the higher base rate of incompetence to stand trial the older you get.
Reference: RL Frierson, SJ Shea, and ME Shea, 2002. Competence-to-stand-trial evaluations of geriatric defendants. J Am Acad Psychiatry Law 30:2:252-256 (2002).