This juxtaposition of enhanced destructive processes with diminished (or inadequate) protective or restorative ones can culminate in cellular damage and physical disease (Table I). This model will

be explored in greater depth in the following sections. Table I. Possibly damaging and protective mediators in major depression LHPA, limbic-hypothalamic-pituitary-adrenal; DHEA, dehydroepiandrosterone; BDNF, brain-derived neurotrophic factor. * Evidence is mixed as to whether DHEA concentrations are elevated or lowered … Moderators Psychological stress and individual Inhibitors,research,lifescience,medical differences Psychological stress is frequently a precipitant of depressive episodes,19 Inhibitors,research,lifescience,medical and under certain circumstances it can initiate the biochemical cascade described here.7,8,10,13,16,20 It is selleck catalog apparent, though, that individuals respond very differently to stress,

due, in part, to differences in coping strategies, disposition, temperament, and cognitive attributional styles.21-23 These can moderate stress-associated biological changes such as LHPA axis arousal,23 inflammation,22,24 neurogenesis,25 amygdala arousal,26 and cell aging. In the first study examining a personality trait and telomere Inhibitors,research,lifescience,medical length, O’Donovan et al found that pessimism was related to shorter telomere length, as well as higher IL-6 concentrations.22 In a study of the effects of early-life parental loss on later-life depression, the quality of the family and home’s adaptation to the loss was the single most power-ful predictor of adult Inhibitors,research,lifescience,medical psychopathology, and was more important than the loss itself.27 Biochemical aspects of resilience vs stress vulnerability will not be covered here but have recently been reviewed.28 Adverse childhood events Alexander Inhibitors,research,lifescience,medical Pope noted in 1734, that “as the twig is bent, the tree is inclined.” A rapidly expanding body of evidence suggests that early-life adversity

(such as parental loss, neglect, Carfilzomib and abuse) predisposes to adult depression27,29 as well as to LHPA axis hyper-reactivity to stress,27,30 increased allostatic load,13,31 diminished hippocampal volume (although this is controversial),32 lower brain serotonin transporter binding potential,33 and a myriad of adult physical diseases.34 Childhood adversity also predisposes to alterations in many of the mediators presented in our model of stress/depression/illness/cell aging, such as: inflammation,35,36 oxidative stress,37 neurotrophic factors,38 neurosteroids,39 glucose/insulin/ insulin-like growth factor (IGF-1) regulation,40 telomerase activity,41 and telomere length.