Abstract
Over the last century there has been a profound transformation in the role of the father. After thousands of years in which families were organized around a patriarchal model, within a few decades family systems have transformed into what can be defined as the contemporary nuclear family. Research has highlighted how important the father is today from the beginning of conception and throughout the early childhood of his offspring. This has influenced not only the relationship between the couple and with their children, but also on the biological structure of man, with changes on the epigenetic and neuroendo- crine level inevitably also influencing the psychological health of the father. Today we know that paternal perinatal affective disorders are almost as frequent as female ones, but their diagnosis is difficult as fathers tend to express their emotional difficulties differently from women. A significant step forward in the study of fathers (and mothers) is represented by their evaluation in a systemic ecological perspective.