We may feel we have to release the pressure by drinking, becoming sexually promiscuous, or violent.
We may become depressed or manic or even psychotic.
Usually, once the perceived threat has passed, we can count on our brains to reset back to normal. Scientists refer to this as homeostasis. You may have come across the term in relation to the environment. Complex systems have a way of self-organizing and maintaining a state of equilibrium.
But if we have some kind of genetic vulnerability, something different may happen. We may reach a state of allostatic overload. Our brain fails to shift back to equilibrium. Instead, we experience free-fall as our 100 billion neurons brace themselves for a hard landing. Suddenly, a good deal of the world may seem threatening most of the time.
In short, we are living in a constant state of stress. We are living in our emotions. The thinking parts of the brain are in thrall to the non-thinking parts of the brain. This applies whether we see ourselves in danger or in love. The cortical regions aren’t getting through. We can’t turn off the limbic system. We can’t think.
In a pleasure situation, neurotransmitters such as dopamine are pumping full force, along with feel-good hormones.
In a stress situation, the dopamine is still going, but it is stoking our awareness and arousal to the point of paranoia. Meanwhile adrenaline and stress hormones are flooding the system. Our adrenaline and stress hormones prime us for fight or flight, but we have nowhere to go.
The hippocampus is also located in the limbic regions. The hippocampus has a lot to do with traumatic memory. Thus, in a stressful situation, the amygdala is likely to pull a deeply-imprinted memory from the hippocampus. Then the alarm goes off. This is why a combat veteran for no apparent reason may over-react to the sound of a car engine backfiring or why a rape victim may feel extremely uncomfortable at the sight of a face in the crowd.
The hippocampus is of particular interest due to the fact that new cell growth occurs there. Conversely, we have strong evidence of cell deterioration there and in other regions of the brain due to the effects of stress.
