Dysfunction of the neural network associated with sustained attention in cancer patients with clinically significant depressive symptoms

Introduction: A breast cancer diagnosis is a major stressor in women that might mediate disabling depressive symptoms. Dysfunction of the neural network associated with attentive processing of emotional information has been considered an important pathophysiologic mechanism of depression. Attention deficit and related brain abnormalities in patients with clinically significant depressive symptoms were investigated by comparing patients without clinically significant depressive symptoms when they were diagnosed with breast cancer. Methods: Twelve breast cancer patients with clinically significant depressive symptoms and 12 breast cancer patients without clinically significant depressive symptoms participated in this study. A psychiatric assessment and attention task were performed during a positron-emission tomography (PET) scan. Independent-samples t-tests, Pearson correlation, and statistical parametric mapping analyses were performed. Results: The performance during the sustained attention task was worse in the depressed group than in the nondepressed group, with the behavioral performance being negatively correlated with the severity of depressive symptoms. The regional glucose metabolism during the task was markedly reduced in four brain regions, including bilateral dorsolateral prefrontal cortices. Regional [F-18] fluoro-2-deoxyglucose uptake in the right dorsolateral prefrontal cortex was significantly correlated with behavioral performance. Discussion: Deficit in sustained attention and related brain abnormalities were found in breast cancer patients with significant depressive symptoms in this study. As a reactive change to a psychosocial stressor, depressive symptoms might be associated with brain dysfunction after a cancer diagnosis. Prefrontal dysfunction may play an important role in the pathophysiology of attention deficit in depressive disorder.