TASTE AND ODOR - REACTIVITY IN DEPRESSIVE-DISORDERS, A MULTIDISCIPLINARY APPROACH

Depressive patients often complain about dullness of taste of previous ly liked food items as well as of persistent bad taste. Taste and smel l experience can be reflected by cognitive (psychophysical) indicators and also by reflectory (facial expressive) responses. In the present study 21 depressed, hospitalized patients and 16 control subjects were exposed to food-related gustatory and olfactory stimuli. Psychophysic al and videotaped facial reactions were recorded from both groups. Ana lysis indicated that cognitive estimates of taste hedonics were simila r for depressed and control groups; the former responded to sweet tast e with a shorter-lasting facial reaction, involving markedly fewer fac ial features expressing enjoyment, than did controls. Aversive tastes, in contrast, triggered comparable facial expressive features of disgu st in both groups. Facial reactions of depressed patients to acceptabl e and aversive olfactory stimuli were all significantly shorter and mo re muted than those of controls. Facial reflexes triggered by chemical cues are known to be controlled primarily by brainstem structures. Pr esent findings suggest a possible influence of the profound anhedonia of severe depression on subcortical processes.