Background and Objectives: One of the most significant psychiatric problems in women is depression related to the perinatal period. Our study aims to determine the frequency and course of depressive symptomatology in the perinatal period with particular reference to objective rate and outcome of postpartum depression. Materials and Methods: One hundred and eighty-eight pregnant/postnatal women were included in a prospective, longitudinal, observational study during which the depressive symptomatology was estimated at the third trimester of pregnancy, and the first, sixth, and twelfth month‚ postpartum. All participants completed a semi-structured sociodemographic questionnaire constructed for research purposes, the Edinburgh Postnatal Depression Scale, Toronto Alexithymia Scale, Beck Anxiety Inventory, and The Mood Disorder Questionnaire at each time point. Postpartum depression diagnosis was confirmed by a trained and certified psychiatrist with long-standing experience. For a better understanding of the trajectory of depressive symptomatology and genuine postpartum depression, we classified depression into those with new-onset and those left over from the previous observation period. Results: In general, 48.9% of participants in the study were depressed at some point during the investigation. A total of 10.6% of women were depressed in the third trimester. The highest percentage of new-onset depression (25%) was in the first month after giving birth and was maintained for up to six months, after which the appearance was sporadic. Most of the postpartum depression resolved in the period from the first month to the sixth month after childbirth (20.7%). The episodes mainly had characteristics of unipolar depression. Conclusions: Our results imply that a new onset of depression is most intensive during the first six months, and after that, it is sporadic. Further studies are needed to explore whether all depressive symptomatology in the postnatal period is the same, or perhaps postpartum depression, classified in this way, has specific characteristics, etiology, and consequently different treatment and preventive options.