The ethological approach to the assessment of depressive disorders.

The ward behavior of 29 inpatients with a diagnosis of major depressive disorder and that of six mixed psychiatric patients was studied by means of an observational method derived from ethological techniques. By these means the occurrence of a wide variety of behaviors was monitored. Depressives before treatment differed from the same group after 4 week of treatment on several items: eye contact, exploration of the environment, verbal communication, and all social behaviors increased, whereas crying, nonsocial behaviors, and pathological behaviors decreased. The same behavioral categories distinguished depressed patients in baseline conditions from controls. When depressives were divided into responders and nonresponders on the basis of their Hamilton scores, behavior differences were notable only in the responders. Some behavioral patterns, such as the rate of social behaviors, were related to personality traits, which were assessed by means of the Maudsley Personality Inventory. Finally, some behavioral categories bore some weak, though significant, relationships to the Hamilton Rating Scale. The above results seem to indicate that a behavior pattern specific to depressive psychopathology does exist and closely resembles the one identified by the classical clinical description of depression. Ethological assessment may therefore be a useful tool in psychiatry, as it can evaluate the clinical picture in a different frame of reference from psychiatric interviews.