Depressive Disorder in Thyroid Cancer Patients after Thyroidectomy: A Longitudinal Follow-up Study Using a National Cohort

Objective The present study compared the frequency of depressive disorder in patients with thyroid cancer who had undergone thyroidectomy with the frequency in control individuals. Study Design Retrospective population-based cohort study. Setting This study used data from the Korean Health Insurance Review and Assessment Service-National Sample Cohort. Subject and Methods A total of 3609 participants with thyroid cancer who had undergone thyroidectomy between 2003 and 2011 were enrolled in this study and matched 1:4 with 14,436 control participants by age, sex, income, and region of residence. The cumulative incidence of postoperative depressive disorder was evaluated over a period of 10 years after the thyroidectomies and compared with the incidence in controls. Depressive disorder was diagnosed by a psychiatrist. Results The incidence of depressive disorder was significantly higher in the thyroid cancer with thyroidectomy group than in the controls up to postoperative year 1. A subgroup analysis showed the same higher incidence of depressive disorder in the thyroid cancer group than controls for up to 1 year after operations in young adult (<= 44 years old), female, urban, and low-income groups. However, the incidence was elevated only in the year of the thyroidectomies themselves in middle-aged and older, rural, and high-income groups. Conclusion Patients with thyroid cancer who undergo thyroidectomy have depressive disorder more frequently than normal controls. However, the frequency of depressive disorder after thyroidectomy recovers in a shorter period in middle-aged or older, high-income, and rural-dwelling patients, compared to younger, low-income, and urban-dwelling patients.