When we experience trauma, our brain is changed. The excellent book "The boy who was raised as a dog" (by Perry & Szalavitz), explains in the second chapter how our brains can experience sensitization. The following is my understanding of this from both the book and my own personal experience of trauma.
Sensitization works like this: We experience a traumatic event, and our brain becomes more sensitive to the stimuli we've experienced. For example, one day we hear a gun shot and see something traumatic happen. Our brain logs the stimuli of the gunshot, and becomes more sensitive to loud noises. This could mean that a year later, we hear a car backfire, and our brain responds as if it were a gun shot, resulting in us hitting the deck, with our body surging with adrenaline.
How the sufferer can respond to sensitization:
1) Knowing that this is a normal pattern of the brain, can be immensely helpful. Instead of feeling like a brain injury patient, you can feel more like a person made in the image of God, with a brain functioning how God made it to.
2) Knowing the benefits of sensitization can be helpful. God has made our brains this way, presumably to protect us from further trauma. Sensitization can lead to incredibly quick and useful responses to harmful stimuli. In my case, by God's grace, I saved a couple of lives, and protected myself many times because of sensitization. I see the sensitization in my brain as part of Father God lovingly taking care of me as one of his sons.
3) Knowing that sensitization is not really an overreaction. OK, technically, I think scientists would say, the trauma survivor's reaction to the car back firing is an 'overreaction' to the present stimuli; but I think there's a more helpful way to view it: It is not an overreaction to the present stimuli, but a commensurate reaction to events both present and past. Here's why this matters: If I frame my jumping to the ground as an overreaction, then I will shamefully see myself as the problem, and wish I was different, and try harder to be different, whilst ignoring the past trauma I'm still reacting to. If, however I frame my hitting the deck as a commensurate reaction to both the past trauma and the present event, then, I understand how much the past trauma is effecting me, and I know what still needs to be dealt with - the past trauma.
4) Processing the past trauma. This is beyond the scope of this blog post, so I will just briefly explain that I need to work through the past trauma, with someone witnessing the trauma, validating my feelings, and helping me see any lies I might be believing about that trauma. I touched on this here.
5) Using sensitization to grow. My reactions to certain stimuli teach me how to grow in my response to a fallen world. I faced a number of life threatening situations as a child which were obviously very scary to me, and affected how my brain works. As an adult, when I've experienced life threatening experiences, I've found that afterwards I feel shaken and upset. One the one hand, that's to be expected, but on the other hand, knowing about sensitization, I know that part of my shakiness and upset is due to my childhood experiences. So, these are opportunities for growth. I grow by mourning the past events, and by renewing my mind (Rom 12:2). Now, I'm armed with a truth I did not know when I was a child, now I know that God is sovereignly in control of everything, and will only permit certain things to happen if its for my good and his glory (Rom 8:28 etc.). So, firstly, I live off a regular diet of meditating on this truth. Secondly, after life threatening events, I now process them through this grid, considering how God was in control the whole time. Thirdly, I've processed the past events through this grid too. So, knowing about sensitization leads to the renewing of my mind, and the healing of past hurts.
How can friends respond to a trauma survivor's sensitisation:
1) Don't tell them they're overreacting. That's as useful as telling someone to 'Calm Down!' Instead, recognise that their reaction is probably a commensurate reaction to past and present events.
2) Consider if you are adding to their trauma in any way. When you think they're overreacting, have you in any contributed to that? For example, if they were traumatically betrayed in their childhood, have you just betrayed them in some small way? If so, don't minimize your actions by saying, "you're overreacting", instead quickly confess your wrong to them, no matter how small it might be. This will firstly help your own relationship with God, and secondly, be very healing to your friend. It might even be the first time a betrayer has repented to them - just imagine how healing that could be! The flip side, is that if you don't confess how you've hurt them, they are going to be feeling double pain, not just the pain of what you've done, but the pain of the past being replayed in their brain.
3) Be a trusted friend on their side. Our natural instinct to other people's sensitization is to be impatient and judgmental, thinking, "oh come on, just get over it, stop making stuff such a big deal." But when we think like that, we're beginning to cross over from being on the same side, to the other side of the road, which then easily leads to being in opposition to our friend. Instead, let's remember that we're on the same team. Let's show our friend that we're with them and for them, and will mourn with them (Rom 12:15). Let's show them they can trust us. If we do this, they might feel safe enough to trust us with helping them use sensitization to grow. For example, there's a small number of people to whom I can say, "you know, I think I'm really hurt because of how similar that thing is to what happened when I was a child." These are invaluable people in my life, worth their weight in gold. They are people who I can easily trust to give me the encouragement to keep on growing for God's glory.