Plasma growth hormone: Effect of anxiety during flooding in vivo

The treatment of phobias by rapid in vivo exposure to the feared situation was accompanied by an increase in plasma growth hormone levels on at least one of two occasions in 8 of 11 subjects. The average growth hormone response was greater on the second occasion, even though subjective anxiety was less. Plasma growth hormone was not elevated during the subjects' adaptation to the laboratory. Strong subjective and behavioral anxiety responses failed to elevate plasma growth hormone levels in some subjects. The probability of a growth hormone response was the same whether or not baseline levels were elevated prior to exposure.