Cognitive expectations of a diffuse and certain danger. An internal physiological preparedness to deal with the threat (e. g. increased heart rate) and an external physiological sign of anxiety (e. g. pale skin, trembling) An emotional sense of dread, fear, panic or worry. Behaviors directed at escaping or avoiding the source of anxiety. *anxiety is adaptive if it motivates effective behaviors, but if the behavioral component becomes maladaptive, it is referred to as an anxiety disorder. Agoraphobia (fear of open spaces) prevents the person venturing outside the house. What causes physical symptoms of panic attacks: lactic acid (a by product of muscular activity) and breathing air with elevated levels of co2. Yohimbine (an 2 adrenergic receptor antagonist) and caffeine- have direct pharmacological effects on the nervous system. People with panic disorder have a family history of anxiety disorders. Pharmacological treatment: benzodiazepines: clinically used benzodiazepines such as diazepam or clonazepam (i. e. valium) are full agonists at the benzodiazepine receptor.