Theta oscillation and functional connectivity alterations related to executive control in temporal lobe epilepsy with comorbid depression

•Behavioral tests and EEG signals were recorded simultaneously.•EEG functional connectivity is weakened in patients with temporal lobe epilepsy (TLE) with comorbid depression.•Weakened functional connectivity may help predict the depression in patients with TLE. Depression is widely acknowledged as the most common comorbidity of temporal lobe epilepsy (TLE), and executive control (EC) may be particularly impaired in patients with TLE with comorbid depression. The purpose of this study was to investigate brain network alterations in patients with TLE with or without depression using scalp electroencephalography (EEG), and to explore the potential mechanisms of TLE with comorbid depression. Forty patients with TLE and 20 healthy controls (HC) were recruited for administered the BDI-II and HAMD-17 surveys. The patients with TLE were divided into those with depression (PDS, n = 20) and those without depression (nPDS, n = 20) according to the surveys. Neural oscillations and functional connectivity during performance of EC tasks were calculated during EEG. Theta oscillation and functional connectivity were significantly weakened in the PDS group compared to the nPDS and HC groups. Furthermore, the PDS group showed more serious EC dysfunction than nPDS group. Our results indicated that weakened theta oscillation and functional connectivity in the frontal lobe may be a mechanism of EC dysfunction in TLE with comorbid depression. The present results suggest that the alterations in frontal lobe connections may help predict the depression in patients with TLE.