Discusses endogenous benzodiazepine-like substances - what do they do, do they affect the anti-anxiety drugs and their adverse effects? Presents information on the enigmatic prolonged benzodiazepine withdrawal syndrome Describes the compounds acting at the BDZ binding sites, both exogenous (classical BDZ drugs and BDZ from food and plants) and endogenous (endozepines) Assesses the putative interactions in physiology, pathology and pharmacology of the compounds acting at the BDZ binding sites