Ethological studies of depressed patients.

The use of ethological methods for characterising the non-verbal behaviour of depressed patients and quantifying change during treatment is described. Approximately 150 individual motor patterns--expressions, gestures and movements--have been defined and this element list provides the basis for encoding video-recordings of interactions. Data quality is controlled by inter- and intra-observer comparisons and by a split-screen technique which simultaneously displays a computer animation of a data file and the original video-recording. Two investigations of the characteristics of non-verbal behaviour in Depression are discussed. The first showed that the frequency and duration of many items of behaviour of depressed patients interviewed soon after admission to hospital differed significantly from matched controls. Recordings of an interview at an intermediate point in treatment showed a reduction in these differences and they had disappeared when examined shortly before discharge. The second study was of mothers suffering from Post Natal Depression who were interviewed once. This study provided evidence that quantification of non-verbal behaviour can distinguish between diagnostic subcategories and showed some of the fine detail of behaviour which can be revealed in this way.