An increase in levels of cortisol can cause an altered brain state. Cortisol, a powerful stress chemical, is released when the brain recognizes a stressor—and the brain is the first body organ to do so. It responds at nanosecond speed to trigger the stress response. Cortisol is part of that stress response and has many important functions including working with the thyroid gland and assisting with the fight-flight stress response. Studies identified elevated 24-hour urinary cortisol production in patients who recently attempted suicide compared with patients who, although depressed, did not have a history of suicidal behavior.