2 2 5ear Colleagues,Anxiety results from the stimulation of innate brain systems that respond to pos-sibly threatening changes in our world. Thus, anxiety is linked to the cognitive evalua-tion of both internal physiological variables and external parameters in the environment.At the simplest level of organization, anxietys manifestation is the flight response in thelower forms of organism. In more evolved species, the emotional component of anxi-ety becomes more visible and modulates behavior that is less genetically determined. Inhumans, the psychoanalytic approach greatly modified the symptomatic description ofanxiety disorders, which were subsequently conceptualized as neuroses. Our knowledgeof anxiety has undergone a new revolution in recent decades, with the discovery of newpharmacological and psychotherapeutic approaches.This is the first of two issues of Dialogues in Clinical Neuroscience devoted to anx-iety.A series of neuroscience and clinical articles will attempt to shed some light on var-ious aspects of anxiety, such as its biological basis, the role of genes, the validity of humanmodels, and the current state of neuropsychopharmacology in this indication. Numerousother questions will probably come to the readers mind.We want to express our appre-ciation to the authors who contributed to this issue for the challenging thoughts theyoffer to the readers of Dialogues in Clinical Neuroscience.Yours sincerely,Jean-Paul Macher, MDMarc-Antoine Crocq, MDE d i t o r i a lD