Abstract
"Anxiety disorder" has varying, symptom-based, definitions and poor targeting of treatments. This chapter describes a novel anxiety-process biomarker, goal-conflict specific rhythmicity, that appears linked to an anxiety syndrome. The biomarker is sensitive to drugs that affect anxiety but not panic or depression. The syndrome it detects, therefore, must cut across existing types of anxiety diagnosis and be distinct from depression. Both the nature of the biomarker (modelled on rodent hippocampal rhythmicity) and the relatively slow onset of drug effects on clinical anxiety suggest that the key underlying process is one that maintains (or prevents habituation of) anxious memories. Variation in the biomarker in healthy and clinical population is consistent with the syndrome reflecting an extreme of an otherwise adaptive personality trait. In its current form, the biomarker is only suitable for single test group analysis. Future work is needed to improve its stability and sensitivity.