BIELEFELD, Germany, Feb. 12 Chronically elevated cortisol levels can be damaging to mood and immunity, but a short spike in the stress hormone may be protective, say German researchers.Our study suggests that when it comes to the negative effects of stress on the emotions, an anticipatory rise in cortisol levels prior to a stressor might help someone to cope with the stressor more efficiently, say psychologists Serkan Het and Oliver Wolf of the University of Bielefeld. This might have implications for treating and preventing post-traumatic stress and other anxiety disorders.The researchers enlisted 44 healthy women for a double-blind study in which one group was given either a 30-mg dose of oral cortisol or a placebo. Experimenters tracked participant mood through self reporting and measured their cortisol levels with a swab check of their saliva before and after the psychosocial stress test.After the stress test the cortisol-treated women developed, on average, fewer negative mood states as a result of the stress-producing activity when compared with placebo-treated women. The high dose of cortisol seems to have worked as a buffer, according to the study published in the journal Behavioral Neuroscience.Copyright 2007 by UPI