PTSD is all about brain chemistry and what happens to the brain during and immediately after the critical, traumatic incident. Essentially, the chemicals that flood the brain during the trauma do so in order to help the person to survive the event, either by running away, or fighting furiously. A third option, to submit to the trauma also has brain chemistry implications. In some individuals, once the brain goes through this chemical ‘rewiring’ to survive the trauma, the wiring stays that way.

When a person has experienced a traumatic event, and depending on their unique brain chemistry, they may or may not have after effects of PTSD symptoms and behavioral signs. This means that two people can experience the same trauma, and one may come out with PTSD, and the other will not. Science may be getting close to predicting who may and who may not develop symptoms, since recent research and study in this area is gaining more information on just how the brain and brain chemicals are involved, and how the process that creates symptoms works.

The parts of the brain that are most involved in PTSD are the amygdala, hippocampus, medial front cortex, thalamus, hypothalamus and the hypothalamic-pituitary-adrenal axis. Along with these, chemicals in the brain such as noradreneline, dopamine, serotonin, the opiod systems, insulin, and cortisol all play complex roles in the PTSD symptom producing process. This complexity is why there has not yet been developed an effective medication to help those who suffer from PTSD to gain relief from all of their symptoms.

Recent research shows that chronic stress of the traumatic type may shrink the hippocampus, and actually kill neurons there, as well as drastically slow down the growth of new neurons. In addition to this startling finding, the ‘wiring’ of the brain’s neurochemical systems become over sensitized, and this results in the symptoms commonly seen in PTSD. The complex chemical-neurological reactivity affects parts of the brain that are all about learning, memory, and fear conditioning. This is why child PTSD victims (as well as adults), for example, may have difficulty with learning as easily after the trauma. They also may have fragmented memories of the trauma, or even new events, as well as problems recalling facts. They may even have dissociative memory problems, meaning they have gaps of moments or even days in their memory.

One important chemical that is being debated in research right now is cortisol. The debate is over its role in producing symptoms in those with PTSD, as the role is not yet fully understood. Cortisol is a hormone that is produced in the adrenal gland. It is sometimes called the ‘stress hormone’ because it tends to increase blood pressure, blood sugar levels, and has an immunosupressive effect. For people who are not PTSD, it actually helps restore homeostasis (calmness) after stress. But in some people who have PTSD, there seems to be a lower base level of cortisol production to begin with, and when cortisol is released, their bodies have a hyper-sensitive reaction to it; that is, the cortisol does not work in them like people without PTSD.

When a person is under chronic stress, such as in battle, or a child who is experiencing serial abuse, or a victim of a hostage situation, there is a prolonged cortisol secretion, that over time, may drastically alter what is considered ‘normal’ cortisol levels. In the average person, cortisol levels are highest in the morning, and lowest a few hours after sleep begins. These facts have broad reaching implications regarding behaviors like sleep, getting a PTSD child up and out the door for school, or being calm enough or alert enough to carry out every day tasks.

Since cortisol acts to increase the blood sugar level, insulin production may increase as well, and go into an overdrive situation along with the other chemicals rushing into the PTSD victim’s body. The extra insulin can then crash the blood sugar, signaling the hypothalamus that glucose (the brain’s only source of energy) is being starved from the brain, which in turn triggers a message to the adrenal glands to increase adrenaline, and the cycle of high stress symptoms begins again. The whole bio-chemical process, once begun, travels at lightening speed.

There may be in fact substantial differences of the chemical reactivity between people who have PTSD or the sources of the PTSD symptoms, as there may also be specific brain chemicals that effect specific symptoms from the PTSD symptom cluster. Though there is no research to directly support the supposition that the more often and longer that this bio-chemical process cycles and repeats the more static and less treatable PTSD becomes, the development of co-morbid mental health conditions and persistence of PTSD symptoms over time is well documented.

The good news is that research on how PTSD works in the brain is moving forward, there is hope that the rewired bio-chemical system can be rewired one more time through therapy to help people regain the life they had before their traumatic event.