Associations between depressive symptoms and fronto-temporal activities during a verbal fluency task in patients with schizophrenia

Though depressive symptoms are common in patients with schizophrenia, they are often left untreated and are associated with a high relapse rate, suicidal ideation, increased mortality, reduced social adjustment, and poor quality of life. The present study aims to elucidate the association between depressive symptoms and fronto-temporal activities during a cognitive task in patients with schizophrenia. The fronto-temporal activities of 41 Japanese patients with schizophrenia was evaluated during a verbal fluency task using 52-channel near-infrared spectroscopy (NIRS). Depressive symptoms were assessed using the depression/anxiety component of the Positive and Negative Syndrome Scale (PANSS) five-factor model. The depression/anxiety component of the PANSS five-factor model was negatively correlated with activities of the ventrolateral prefrontal cortex (PFC), right dorsolateral PFC, and left temporal regions. Our findings suggest that reduced fronto-temporal activities on NIRS during a verbal fluency task is related to depressive symptom severity in patients with schizophrenia.