<qa>  What is the effect of glucocorticoids on emotional behavior?Glucocorticoids can influence emotional behavior and cognition; when given long-term, the hormones may lead to mania or depression. One way glucocorticoids may influence emotional behavior is by affecting the activity of certain parts of the brain that participate in emotional processing. Brain imaging studies indicate that the amygdala, ventral medial prefrontal, and other prefrontal cortical areas of the brain are activated during tasks that require processing of emotional stimuli. These brain structures contain dense concentrations of glucocorticoid receptors. This study will use functional magnetic resonance imaging fMRI to study the brain activity of participants as they view faces that express different emotions. Participants will perform this task under a dose of either the glucocorticoid hydrocortisone or placebo an inactive solution. 