Cognitive and behavioural processes may constitute a risk for onset and persistence of depression. People who become depressed frequently show enduring negative cognitions which predispose them to depression. In addition, interpersonal processes are supposed to contribute to the etiology and maintenance of depression. Depression-prone persons are presumed to display deficient or problematic social behaviours that elicit negative reactions in others, finally resulting in withdrawal by family and friends.
About 60% of human communication is non-verbal. An ethological approach may therefore contribute to reveal behavioural and cognitive vulnerability factors for depression onset or persistence. Various studies support this presumption: High levels of patients' observed behaviour indicating involvement in the interaction between depressives and clinicians at admission are related with persistence of depression.
