Component-Specific vs. Diagnosis-Specific Clinical Trial in Depression

By Martin M. Katz

Research indicates that the central neurotransmitter systems most highly associated with the pathophysiology of depression are the serotonin and noradrenergic systems. Basic research links these systems with the regulation of different behaviors and moods, serotonin with impulsive aggression and anxiety, norepinephrine with “arousal” and motor activity (Katz and Maas 1994).

Antidepressant drugs have been found to be equally effective for anxiety, phobic and obsessive-compulsive disorders. Thus, their therapeutic effects in depression are more likely based on the changes they effect in the components of anxiety, hostility and motor functioning, components not necessarily in the “core” pathology of depression. The most effective methods for measuring drug actions are methods for measuring the principal behavioral, mood and cognitive components of the disorder (Katz, Bowden and Frazer 2010).

In 2013, in his Depression and Drugs: The Neurobehavioral Structure of a Psychological Storm, Katz reports findings that the “component specific clinical trial” model is more informative about the range of drug actions and suggests that it is “more efficient” than the traditional, diagnosis-centered clinical trial model, in the study of depression. 



Katz MM. Depression and Drugs. The Neurobehavioral Structure of a Psychological Storm. Berlin: Springer; 2013, pp. 61-71.

Katz MM, Bowden CL, Frazer A. Rethinking depression and the actions of antidepressants: Uncovering the links between the neural and behavioral elements. J Affective Disorders 2010; 120: 16-23.

Katz MM, Maas JW. Psychopharmacology and the etiology of psychopathological states: Are we looking in the right way? Neuropsychopharmacology 1994; 10: 139-44.


Martin M. Katz                                                             

February 27, 2014