Brain functional connectivity in depression: Gender differences in EEG

The aim of the study was to find gender differences in brain functional connectivity in major depressive disorder (MDD). The experiments were performed on 37 unmedicated subjects with MDD (16 male, 21 female) and 37 age and gender-matched healthy subjects. Electroencephalogram (EEG) was recorded from 30 channels and filtered into six frequency bands: whole frequency band (1-45 Hz), delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30 Hz) and gamma (30-45 Hz). Synchronization likelihood (SL) was used to estimate functional connectivity. The experimental results indicated that 1) SL of male MDD subjects was significantly increased in the theta and beta frequency bands compared to control group and 2)SL of male MDD subjects was significantly increased in the theta frequency band compared to female MDD subjects. No significant difference was found between female MDD subjects and female control group as well as between healthy male and female subjects. Although similar trend occurred in case of both genders, the results of the study indicate a significant difference between EEG of male and female MDD.