A correlational study between signature, writing abilities and decision-making capacity among people with initial cognitive impairment

Some clinical conditions, including dementia, compromise cognitive functions involved in decision-making processes, with repercussions on the ability to subscribe a will. Because of the increasing number of aged people with cognitive impairment there is an acute and growing need for decision-making capacity evidence-based assessment. Our study investigates the relationship between writing abilities and cognitive integrity to see if it is possible to make inferences on decision-making capacity through handwriting analysis. We also investigated the relationship between signature ability and cognitive integrity. Thirty-six participants with diagnosis of MCI and 38 participants with diagnosis of initial dementia were recruited. For each subject we collected two samples of signature—an actual and a previous one—and an extract of spontaneous writing. Furthermore, we administered a neuropsychological battery to investigate cognitive functions involved in decision-making. We found significant correlations between spontaneous writing indexes and neuropsychological test results. Nonetheless, the index of signature deterioration does not correlate with the level of cognitive decline. Our results suggest that a careful analysis of spontaneous writing can be useful to make inferences on decision-making capacity, whereas great caution should be taken in attributing validity to handwritten signature of subjects with MCI or dementia. The analysis of spontaneous writing can be a reliable aid in cases of retrospective evaluation of cognitive integrity. On the other side, the ability to sign is not an index of cognitive integrity.