In central nervous system structures, the glucocorticoid receptor is gaining interest as a novel representative of neuroendocrine integration, functioning as a major component of endocrine influence - specifically the stress response - upon the brain. The receptor is now implicated in both short and long-term adaptations seen in response to stressors and may be critical to the understanding of psychological disorders, including some or all subtypes of depression and post-traumatic stress disorder ( PTSD ).  Indeed, long-standing observations such as the mood dysregulations typical of Cushing's disease demonstrate the role of corticosteroids in regulating psychologic state; recent advances have demonstrated interactions with norepinephrine and serotonin at the neural level.  
Hydrocortisone is the pharmaceutical term for cortisol used in oral administration, intravenous injection or topical application. It is used as an immunosuppressive drug , given by injection in the treatment of severe allergic reactions such as anaphylaxis and angioedema , in place of prednisolone in patients who need steroid treatment but cannot take oral medication, and perioperatively in patients on longterm steroid treatment to prevent Addisonian crisis . It may be used topically for allergic rashes, eczema , psoriasis and certain other inflammatory skin conditions. It may also be injected into inflamed joints resulting from diseases such as gout .