New biological research relevant to anxiety.

It is reasonable to suggest that further understanding of the physiology and the mode of action of the drugs that are most effective in decreasing human anxiety, the BDZ, may provide important clues to the understanding of anxiety. BDZ receptors have recently been discovered in human brain where they have a differential distribution. Good correlations have been obtained between the clinical potency of a series of BDZ and the tightness with which they bind to brain membranes. It has been discovered that BDZ may exert part of their therapeutic action by enhancing the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). Thus it appears that some of the actions of diazepam may be a result of increasing the ability of GABA to quiet brain cell activity. A number of endogenous compounds have been discovered that are produced in brain and that may act like BDZ, but at the present time no single candidate has convincingly emerged as the endogenous BDZ. A world-wide search for the endogenous BDZ continues. Finally, a brain structure, the nucleus locus coeruleus, has been proposed as possibly relevant to anxiety-like behavior. Electrical stimulation of this area can produce anxiety-like behavior in monkeys that can be blocked by diazepam. Thus, for the first time in many years, the above-mentioned discoveries have increased hope that significant progress will be made in our understanding of the severe and at times incapacitating mental problem of severe anxiety.