"Psychopharmacology of the Aging Nervous System" was selected as the topic for Volume 20 of the Handbook of PsychopharmacoloffY. Senile dementia is now widely recognized as a medical and social problem likely to reach epidemic proportions by the turn of the century. By that time it is esti- mated that almost 20% of the population in most developed countries will be over the age of 65 and at a conservative estimate 1 in 10 of them will suffer from...