[Biological factors of PTSD: neurotransmitters and neuromodulators]

Subjects with posttraumatic stress disorder exhibit abnormalities in many psychobiological systems. Studies of the effects of stress on learning and memory processes suggest that fear conditioning, behavioural sensitisation, and a failure of extinction may be important in the persistence and reexperiencing of traumatic memories and stress sensitivity. All these symptoms are supported by specific biological mechanisms including NMDA receptors, noradrenergic system, etc. Recent findings show that amino acid transmitters, glutamate and GABA, are intimately involved in the process of factual memory registration, and suggest that amine neurotransmitters, norepinephrine and serotonin, are involved in encoding emotional memory. In addition, research suggests that 5-HT neurones have directs effects on both adrenergic and HPA function. Such findings provide important information that should guide current pharmacological practice and the development of innovative biological therapeutics.