ABSTRACT
A study by Egeland and Sussex reporting on suicide and family loading for mood disorders over a 100-year period among the Old Order Amish found that the majority of the suicides were among four primary family pedigrees with heavy loading for mood disorders. Despite the compelling evidence documenting the influence of seasonal phenomena in the natural course of major mood disorders, relatively few studies have investigated psychobiological variables with seasonal variations. While serotonergic mechanisms have been heavily implicated in the etiology of mood disorders, there is little work to date examining the role that serotonin (5-HT) may play in the apparent seasonal vulnerability of patients with general mood disturbances. However, the pronounced positive therapeutic response of patients with SAD to the 5-HT-releasing agent d-fenfluramine should provide the impetus to continue more selective studies of serotonin dysregulation in mood syndromes with a pattern of seasonal recurrence.
