was also found after fenfluramine challenge, but the effects were not as statistically robust as those with cortisol.
The stress response also affects the structure and function of noradrenergic pathways. Fewer noradrenergic neurons in a nucleus found in the brain stem, the locus coeruleous, have been found postmortem in studies of depressed patients who completed suicide (Pandey and Dwivedi, 2007). The noradrenergic system is also a target of antidepressant treatments. Adults reporting past child abuse have excessive norepinephrine release after a laboratory stress test (Heim and Nemeroff, 2001). A noradrenaline metabolite in the cerebral spinal fluid predicts the lethality of a suicide attempt (Galfalvy et al., 2009). One key hypothesis, observed Mann, is whether excessive norepinephrine release related to the long-standing stress of severe major depression in those with childhood adversity or in genetically predisposed people eventually leads to hopelessness and pessimism. Those psychological traits, in turn, place these people at higher risk for suicidal behavior.
In summary, Mann believes that biological markers such as low serotonin levels predict future completed suicide. Biological findings, along with other psychological and social risk factors, may eventually be used in an integrative way to shed light on the emergence of suicidality in childhood, adolescence, and adulthood (Box 2-1).
Summary of Research Findings Reported by Presenters in This Session