In the spring of 1987, I was in Havana, Cuba, where I was participating in planning a large-scale longitudinal study of the neurophysiological, neurochemical, and behavioral characteristics of cohorts of patients with cerebrovascular disease, depression, senile dementia, schizophrenia, or learning disabilities; and also part of this study were their first-degree blood relatives. This study was the outgrowth of a long-term project on the practical...