The objective was to assess the impact of cognitive factors on post-partum depression (PPD) symptoms. Because most of the literature data concern the immediate post-partum period or the first year post-partum, we notably sought to assess the longer term impact of cognitive factors on the symptoms of PPD. Two studies were performed. In a pilot study, 1-month post-partum, 63 women filled out a sociodemographic information sheet and completed the abbreviated, revised Eysenck Personality Questionnaire, the Ruminative Responses Scale, the Maternal Self-Report Inventory, and the Edinburgh Post-Natal Depression Scale. In the main study, 124 women additionally completed the Toronto Alexithymia Scale. The main study population was divided into 2 subgroups: women in the first year post-partum (n = 74) and those in the second year post-partum (n = 50). In the pilot study performed 1-month post-partum, brooding rumination and low self-esteem were significant predictors of the PPD symptom intensity. Neuroticism, brooding rumination, and low maternal self-esteem were also significant predictors of the PPD symptoms reported in the first year post-partum. Lastly, ruminative thoughts and alexithymia were significant predictors of the PPD symptoms reported in the second year post-partum. Our results suggest that alexithymia may be an important predictor of the incidence of this condition. The observation of differences in the PPD models as a function of the post-partum period may open up opportunities for developing novel PPD prevention/treatment programs.