All 4 Terms & Definitions
- Dimensional continuum
- Anxiety exists on a continuum of severity across the population rather than falling into discrete categories. Diagnostic thresholds in DSM-5 and ICD-10 represent clinically useful cut-points on this dimension, but the underlying biology and psychology operate dimensionally — which is why subclinical anxiety still causes functional impairment.
- Overgeneralisation of conditioned fear
- A proposed pathophysiological process in which fear originally learned in response to a specific stimulus extends to stimuli that are similar to, or merely associated with, the original threat — often spreading to stimuli that pose little or no genuine danger. Thought to be a key mechanism maintaining many anxiety disorders.
- Deficit in fear extinction
- Impaired ability to inhibit or suppress a conditioned fear response when the threat is no longer present. Extinction is thought to create a new competing inhibitory memory rather than erasing the original fear memory. In anxiety disorders, this new learning may be weaker or less stable, allowing fear to persist or return after apparent remission.
- Amygdala and insula overactivity
- Functional MRI studies in anxiety disorders consistently show overactivity in the amygdala (fear detection and initiation of the threat response) and the insula (interoceptive awareness of bodily states) in response to threat-related stimuli. This neural pattern is consistent with theoretical accounts of overgeneralised conditioned fear and the intense somatic sensations that accompany anxiety.