[Molecular basis of stress-evoked psychiatric disturbances].

Stress, defined as coping with environmental challenges, involves the activation of the neuronal and neurohormonal systems. Central monoaminergic (noradrenergic, dopaminergic, serotonergic) neural networks, limbic structures, the sympathoadrenal system, the hypothalamo-pituitary-adrenal axis, and the immune system are considered the most important stress pathways. Their activation determines stress reactivity and pathological consequences on exposure to situations of distress. Both trauma and long-term stress can cause alterations in the activities of neuroanatomical structures and neural networks within the central nervous system. These neurohormonal changes are associated with post-traumatic stress disorder (PTSD), a disturbance thought to be one of the most serious psychiatric illnesses. PTSD may develop in individuals after exposure to a traumatic event (war, violence, accident) and is manifested by various symptoms, such as re-experiencing, flashbacks, intrusive thoughts, impaired memory of the event, sleep disorders, nightmares, panic attacks, and depression. In this review the neurohormonal changes associated with experiencing stress are presented to highlight the molecular and hormonal basis of PTSD.