Objective. Little is known about the development of psychological wellbeing over time among women who have been treated for breast cancer. The aim of this study was to identify distinct patterns of distress, anxiety, and depression in such women. Methods. We invited 426 consecutive women with newly diagnosed primary breast cancer to participate in this study, and 323 (76%) provided information on distress ('distress thermometer') and on symptoms of anxiety and depression ('hospital anxiety and depression scale'). Semiparametric group-based mixture modeling was used to identify distinct trajectories of distress, anxiety, and depressive symptoms assessed the week before surgery and four and eight months later. Logistic regression analysis was used to evaluate the characteristics of women in the distinct groups. Results. Although no sub-group of women with chronic severe anxiety or depressive symptoms was found, we did identify a sub-group of 8% of the women who experienced continuously severe distress. Young age, having a partner, shorter education, and receiving chemotherapy but not radiotherapy might characterize women whose psychological symptoms remain strong eight months after diagnosis. Conclusion. By looking beyond the mean, we found that 8% of the women experienced chronic severe distress; no sub-groups with chronic severe anxiety or depression were identified. Several socio-demographic and treatment factors characterized the women whose distress level remained severe eight months after diagnosis. The results suggest that support could be focused on relatively small groups of patients most in need.