F. Shaddel, M. Ghazirad, D.O'Leary and S. Banerjee
Oxford University, Oxford, UK
Traditionally, two divergent approaches are used to explain the mechanism of action of psychotropic drugs. The currently dominant "Disease-Centred" approach and the older one: "Drug-Centred" view. In this article we propose a new model for classifying the therapeutic uses of psychotropic drugs based on the relation between their psychoactive effects and symptoms of indicated mental illness; as well as their clinical responses e.g. emerging tolerance, paradoxical initial worsening and being recommended for long/short-term use.
Based on this premise, therapeutic uses of psychotropic drugs can be placed on a continuum between two distinguishable modes: "Psycho-antagonistic" and "Psycho-agonistic". 105 therapeutic uses of 85 psychotropic drugs are placed on this continuum; 74% on the Psycho-agnostic spectrum and 25% on the Psycho-antagonistic side. Hypnotics used for insomnia are clear examples of Psycho-antagonistic mode and Citalopram for treatment of Panic disorder is a clear example of Psycho-agonistic mode. Only the therapeutic use of Lithium for bipolar affective disorder could not be allocated.
The model highlights the possibility of initial worsening in majority of therapeutic uses of psychotropic drugs and importance of using lower doses. Further studies are needed to explore full clinical implications of this model in psychiatry and perhaps in other branches of medicine.