A behavioral-chromosome relationship in the elderly: a critical review of a biobehavioral hypothesis.

The evidence for the hypothesis that an increased frequency of hypodiploid cells is related to mental status in older persons, as well as the underlying assumptions crucial to the hypothesis, are reviewed. Results of chromosome examinations reported by several independent laboratories favor an increasing proportion of hypodiploid cells in older age groups as well as sex differences in the level and distribution of missing chromosomes. However, the presence, extent, and development course of chromosome loss associated with major modifying variables and their interactions, e.g., age, morbidity, sex, environmental conditions, remain to be empirically documented. Furthermore, the meaning of chromosome loss, including its relationship to mental status, is not clear.