While all anxiety disorders share the core features of excessive fear, anxiety, and avoidance,
they differ in the specific object or situation of concern.
They also differ from normal fear or anxiety in terms of duration; symptoms related to an anxiety disorder typically persist for >6 months. Anxiety disorders can only be diagnosed when the physiological effects of substances, other medications, or other medical diagnoses have been ruled out or when the symptoms cannot be better explained by the diagnosis of another mental disorder.Thus, thorough patient assessment should include a review of systems, medication history (including over-the-counter medications), substance use, a complete evaluation of anxiety symptoms, a focused physical examination of symptomatic areas, and a functional assessment. Inquiries about substance use should include questions about illicit drugs (particularly stimulants), alcohol, and caffeine. Further investigations should follow based on the results of the initial assessment (Table 1).