Prediction of clinical change by ethological methods

The aim of this paper is to show that ethology may contribute to the search for early indicators of clinical changes in depression. Three studies are presented. One study deals with the prediction of treatment outcome over 10 weeks and the other two with the prediction of the acute clinical response to total sleep deprivation (TSD). In each study a number of behaviours were observed, as displayed during a baseline psychiatric interview by the patients as well as the psychiatrist. In this report, the predictive potency of directly observed behaviours is compared to the predictive value of global clinical measures of psychomotor activation. The behaviours of the patients were interpreted as "relational" and "nonrelational" behaviours. The relational behaviours (i.e., variation in looking, yes-nodding, gesturing) occurred less, the nonrelational behaviours (i.e., intensive body touching, head movements) occurred more in responders than in nonresponders to 10 weeks of treatment. Also in the TSD studies body touching was positively related to improvement. Global clinical assessment of psychomotor activation could not be related to outcome. The advantages of the observational methods are discussed.