Objective: Patients experiencing their first major depressive episode after receiving a diagnosis of cancer are frequently seen in clinical oncology settings; however, little is known about the neurobiological basis of the first episode. In previous studies, a smaller hippocampus than in healthy comparison subjects has been observed in patients with a history of recurrent and prolonged major depressive episodes. The purpose of the present study was to investigate whether there is an association between hippocampal volume and a first major depressive episode after cancer diagnosis in cancer survivors.
Method: The subjects were 68 female cancer survivors who had undergone breast cancer surgery 3 or more years earlier (mean interval=4.3 years, SD=0.9). The hippocampal volume and delayed recall function of the 17 cancer survivors who had their first major depressive episode after receiving their cancer diagnosis and the 51 with no history of major depressive episode at any time during their lives were measured by magnetic resonance imaging and the Wechsler Memory Scale-Revised, respectively.
Results: The mean duration of the major depressive episode after cancer diagnosis was 11.9 weeks (SD=14.2). There were no significant differences in left or right hippocampal volume or in delayed recall function between the cancer survivors with and without a major depressive episode after cancer diagnosis.
Conclusions: First major depressive episodes after cancer diagnosis in female cancer survivors do not appear to be associated with hippocampal volume. However, a longitudinal study with healthy comparison subjects is needed to draw a definite conclusion.