Frontal alpha asymmetry in major depression and comorbid anxiety disorder: a five-year follow-up study

Major depression (MD) and anxiety disorders are both associated with higher left compared to right frontal alpha activity (rLFα). The aim of the study was to examine whether young adults with lifetime MD and anxiety disorder differ from healthy controls and whether this pattern remains stable over five years from adolescence into adulthood.

Resting frontal EEG asymmetry of n = 25 young adults with lifetime MD and anxiety (MDAnx) and n = 26 healthy controls (HC) was compared. Moreover, in a subsample of participants, the stability of frontal alpha asymmetry was analyzed from adolescence to young adulthood via intra-class-correlations.

Participants with MDAnx displayed significantly more rLFα than HCs. Asymmetry showed fair stability over 5 years in the MDAnx group and poor stability in the HC group, the latter driven by increased relative right frontal alpha activity.

Increased rLFα could be a trait marker for comorbid MDAnx. Low stability in the HC group could derive from maturation of cognitive and affective processes, which might be impeded by the presence of lifetime MDAnx.

Results highlight that EEG asymmetry changes from adolescence to adulthood and could be impacted by lifetime MD and anxiety, irrespective of current symptomatology.