It was hypothesized that personality factors determine the short-term outcome of depression, and that they may do this via non-verbal interpersonal interactions and via cognitive interpretations of non-verbal behaviour. Twenty-six hospitalized depressed patients entered the study. Personality factors in the study were Neuroticism (N) and Extraversion (E). Non-verbal interpersonal interactions were studied by measuring patients' 'support seeking behaviour' and interviewers' 'support giving behaviour' from videotaped clinical interviews. The attunement between patients' and interviewers' behaviour (reflecting interpersonal satisfaction) was calculated over the time course of the interviews. Cognitions were assessed by measuring the perception of emotions from schematic faces. A stepwise multiple regression analysis showed that the higher the levels of E were, the less negative emotions were perceived from ambiguous faces (A-neg), and the more the patients and the interviewers got non-verbally attuned during the baseline interviews, the more favourable the short-term outcome of depression (as assessed over 6 weeks) turned out to be (adj.R2 = 0.48, P = 0.001). High levels of A-neg explained the relationship between high levels of N and an unfavourable short-term outcome of the depression (Pearson's r between N and short-term outcome of depression, P = 0.041, partial correlation after correction for A-neg, P = 0.157). The results show that personality, non-verbal interpersonal behavioural processes and cognitive factors are partially independent and partially linked in their relationship with the short-term outcome of depression. Research on non-verbal behavioural processes extends the empirical basis for the integration of personality, cognitions and interpersonal factors in depression theory.