Symptoms of depression together with trait anxiety increase the ability to predict alpha power change between attention and resting states

Abstract

Research suggests that symptoms of anxiety may result in atypical alpha activity associated with cognitive functioning. It is well documented that symptoms of anxiety are often comorbid with symptoms of depression. However, the combined influence of these symptoms on alpha activity changes between engaged attention states and rest is poorly understood. We therefore aimed to investigate the specific added contribution depressive symptoms may have in predicting alpha power compared to anxiety alone. We measured the disparity in alpha power between a selective attention state compared to a resting state using EEG. Selective attention was engaged using the Eriksen flanker task. Our results show that alpha disparity was predicted significantly better when symptoms of depression were incorporated into the model, compared to trait anxiety alone. Also, both symptoms were significant predictors of alpha power change, but in opposite directions. Alpha disparity increased between rest and attention as trait anxiety symptoms increased, while disparity was negatively correlated with increased symptoms of depression. Clinical symptoms did not predict flanker task performance during incongruent trials, but did strongly relate to global executive dysfunction. Given that clinical symptoms were related to alpha change between attention and rest but not behavioral performance on the flanker task, it is possible that these neural patterns could reflect a compensatory strategy. These results further emphasize the importance of examining how the compounded influence symptoms of anxiety and depression manifest in executive abilities, and add to the growing body of evidence that there is a neurological differentiation between these disorders.

Keywords: Attention; Depressive symptoms; Electroencephalogram; Trait anxiety; alpha power.