Abstract Anxiety disorders share psychological symptoms of subjectively highly distressing and excessive worry, and anticipation of impending danger with the feeling of little chance to escape. At the physiological level, these symptoms are accompanied by tachycardia, hyperventilation, dizziness and nausea, and sweating. Duration and intensity of these symptoms vary greatly between different forms of anxiety disorders, from relatively short periods of time with the greatest intensity in panic disorder (PD), to enduring worrying of minor intensity as in generalized anxiety disorder (GAD). Moreover, there are differences with regards to the situational circumstances that may elicit symptoms of anxiety. In phobic disorders, the precipitating situational context is part of the definition, whereas in PD and GAD these situations are less well determined or absent.