In the modern day, we are learning to put just as much emphasis on mental illness as pathogenic diseases as we realise how important it is to try to help people overcome mental challenges. A very apparent mental problem is Post-Traumatic Stress Disorder. PTSD is a condition triggered by trauma which causes extreme stress and is much more common than most people realise. I intend to look at the causes of the disease, and how we are attempting to help victims of it.
The key to understanding this is to understand how the disorder occurs in individuals. For someone to be affected, something in their environment must cause it by triggering extreme stress. The most associated cause is war; however, PTSD affects just 7% of war veterans. A far greater number of people suffer the condition from more domestic causes, for example rape with 49% of victims developing trauma, and subjects of domestic violence. Paramedics are also very vulnerable with 40% of them developing the disease. Other causes of the affectation include physical assault and abuse, natural disasters, major crashes and terror attacks. It is estimated that 2,500,000 people in the UK have the disease at any one time, and over 4,000,000 develop the disease in their lifetime.
The reason some people are affected more than others is due to the size of their hippocampus. The hippocampus is a part of the brain which is key in learning, emotions and memory, especially short term and is responsible for transferring these to other parts of the brain which stores more long-term memories. It also helps regulate the HPA axis, the link between the pituitary gland and the adrenal gland which also links the amygdala to this circuit, which are responsible in homeostasis and stress regulation. The smaller the hippocampus, the more vulnerable a person is to the disorder. Different sizes can be caused by ageing, neurodegeneration, chronic stress and genetic predisposition to a smaller hippocampus.
Another potential genetic effect is a more sensitive hippocampus, specifically to cortisol, a hormone which causes stress. Cortisol is a very important hormone and is released not just when an exam is around the corner or when you are at a job interview, but also when you go for a run and do exercise, wake up as well as when you eat. It also has a role as an anti-inflammatory agent, on top of its role as a hormone, as it is released while you are infected and ill. It’s role as a hormone is what makes it involved in PTSD, because when someone experiences extreme trauma, a massive release of cortisol can occur which is outside ordinary and healthy ranges. This, combined with a more sensitive hippocampus, can result in a memory being associated by the brain with extreme stress.
After an event triggers excessive release of cortisol, neurodegeneration occurs in the hippocampus, and it shrinks as the neurons are damaged by excessive firing of electrical impulses. A major symptom of PTSD is the vivid re-experience of a fragmented stressful memory, which is caused by this neurodegeneration. This change also damages the HPA axis, resulting in excessive cortisol release and damages the link with the amygdala, which leads to damaged links between emotional responses and perceptions of people’s environment. It also damages the ability of neurons in the hippocampus to change, which is key to the brains ability to learn and change, as well as damaging the unique characteristic of the hippocampus to create new neurons. This means the brain is less able to heal from the event because it cannot create new pathways with less powerful associations.
This means the healing process after trauma is difficult and takes a long time. One current treatment is the use of antidepressants including sertraline, amitriptyline and mirtazapine; however, this is not amazing due to the addictions it causes and the temporary nature of it. A more effective and permanent method is therapy, and talking to therapists who use methods such as exposure to the event, bilateral stimulations and teaching coping mechanisms to slowly reduce the power of the condition over time. This is much slower but can result in a fuller recovery. To speed this up, new techniques are being developed, such as virtual reality therapy, relying on the same principles as exposure therapy, and therapies which monitor brain activity to help people to learn how to regulate their brain. These will allow doctors to heal people and improve their lives much more effectively and quickly.
