PURPOSE: The purpose of this study was to identify subgroups of breast cancer patients and their partners based on distinct trajectories of depressive symptoms, to examine how relationship quality and medical and sociodemographic factors were associated with these trajectories, and to explore whether patients and partners had similar trajectories.

METHODS: A nationwide, population-based cohort of couples dealing with breast cancer was established in Denmark. Participants completed the Center for Epidemiologic Studies-Depression Scale at baseline and 5 and 12 months later. Sociodemographic and medical characteristics were retrieved from registers. A trajectory finite mixture model was used to identify trajectories.

RESULTS: The trajectories of depressive symptoms over time were analyzed in 546 patients and 508 partners. Among patients, 13 % had a high stable trajectory, 38 % an intermediate decreasing trajectory, and 49 % a low trajectory. Similar trajectories were found for partners (11, 22, and 67 %, respectively). Compared to the low trajectory, trajectories with higher depressive symptoms were associated with poorer relationship quality and previous use of antidepressants for patients and partners and with younger age, comorbidity, basic education, and chemotherapy for patients. The trajectories of patients and their partners were weakly correlated.

CONCLUSIONS: A considerable minority of patients and partners had a persistently high level of depressive symptoms. Poorer relationship quality and previous antidepressant use most consistently characterized patients and partners with higher depressive symptom trajectories.

IMPLICATIONS FOR CANCER SURVIVORS: In clinical practice, attention to differences in depressive symptom trajectories is important to identify and target patients and partners who might need support.