The melancholic type is a phenomenological construct useful to recognize and assess persons vulnerable to develop major depression. Its main features are consciousness, orderliness, hyper-heteronomia and intolerance of ambiguity. These features, which mainly describe the social behaviour and the value system of these persons, were first described in qualitative studies mainly developed in Continental and Japanese psychopathology, and later established through quantitative research. The evolution of this construct nicely illustrates how qualitative and quantitative methods may be integrated in an epistemologically sound research agenda.