Abstract
Mental disorder diagnoses are currently based on arbitrary symptom checklists and lack the identification of underlying neurological dysfunction. As a result, clinicians assign diagnostic labels with low accuracy, leading to poor treatment selection and delivery and reduced quality of life for many individuals. Goal Conflict Specific Rhythmicity (GCSR), measured using a Stop Signal Task (SST), appears to be the first neural biomarker for diagnosing one process underlying clinical anxiety. While previous research has shown that GCSR is an ‘anxiolytic-sensitive’ biomarker, the present study aimed to take the first steps toward validating GCSR as a ‘clinical anxiety’ biomarker within a patient sample. According to McNaughton and Corr (2004)’s theory, it was predicted that patients diagnosed with Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) ‘anxiety disorders’ would on average show higher GCSR than control participants. In this study, the Electroencephalogram (EEG) of 86 participants recruited from Student Job Search (SJS) and 21 patients diagnosed with DSM-5 anxiety disorders was recorded while participants underwent a SST. GCSR values of SJS participants who obtained Spielberger’s Trait Anxiety (STAI-T) scores in both the clinically high and normal ranges were compared to GCSR obtained by anxiety disorder patients. Consistent with predictions, GCSR tended to be higher in individuals diagnosed with DSM-5 anxiety disorders compared to SJS controls with low STAI-T scores. GCSR also tended to increase in the positive direction as STAI-T scores increased, with anxious patients producing similar, if not higher, GCSR than SJS participants with STAI-T scores in the clinical range. Overall, these results provide preliminary support for GCSR as the first biological biomarker for one clinical anxiety process. Further research, including a larger sample of anxiety disorder patients and an appropriately matched healthy control group, is required to strengthen conclusions and progress the translation of this biomarker into clinical settings.