Catecholamines and anxiety.

Plasma catecholamines and heart rate were determined in drug-free groups of anxious patients and normal controls before and 20 min after intramuscular injection of 0.01 mg/kg of 1/1000 diluted epinephrine. Levels of anxiety after the injection were determined via the State Anxiety Scale of State Trait Anxiety Inventory. Both groups showed substantial increases in plasma levels of epinephrine and norepinephrine and heart rate after the injection. However, there were no significant differences between anxious patients and controls on plasma catecholamines and heart rate before or after the injection and post injection levels of State Anxiety. The anxious subjects showed a significant correlation between post injection heart rate and State Anxiety.