“Anxiety disorders” are the commonest mental disorders in New Zealand; but their diagnosis is still based on clinical symptom check lists not biological markers of specific causes. In our well-established neuropsychological theory, anxiety involves threat-approach controlled by specific brain structures in which hypersensitivity to input generates specific clinical syndromes. We have developed a specific non-invasive biomarker for threat-approach system activation in humans that shows hyperactivity in some clinical cases with source localisation to right inferior frontal regions. Our project will test this with fMRI and test for the involvement, predicted by our theory, of hippocampus, insula and amygdala. This should provide better understanding of the underlying causes of anxiety and ultimately provide targeted treatments; greatly improving treatment outcomes and cost-effectiveness.