One of the most intricate things found in nature is the brain, and although scientists have been scrutinizing for years on end, the enigmas that the brain presents are far from being unravelled. The brain is the principal part of us, it’s what makes us distinctive to one another (well, that and our DNA). The way we think, the way we behave and the things we do are determined by our brain and how the brain knows how to react in a myriad of scenarios is extraordinary at the very least. But that’s not all that is astounding about the brain, the fact of the matter is that every brain is different and functions in a diverse fashion. It is surprising to know that jellyfish and starfish are a few of the invertebrates that don’t possess brains, but instead use nerve nets to account for the nerve impulses that cause all the messages in their bodies to be passed along.
Physiologically the brain is the central motor that controls the correct functioning of everything else, it is sophisticated machinery that unravels the chemical messages of our systems and implements them. The cerebral cortex alone contains over 20 billion neurons- no wonder it’s the most complex organ! Although we have the basics of how the brain functions pinned down, neurons carry chemical messages (some 10-100 per second) through fibres known as axons via which action potentials are transmitted and communicate with cells through the secretion of hormones, but the way these communicate in countless assemblages is yet to be known. You can see now if something were to go wrong why it would be so complicated to resolve.
“Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations… And by the same organ we become mad and delirious, and fear and terrors assail us, some by night, and some by day, and dreams and ultimately wanderings, and cares that are not suitable, and ignorance of present circumstances, desuetude, and unskillfulness. All these things we endure from the brain, when it is not healthy.”
Hippocrates, On the Sacred Disease
Anxiety disorders are also a category of mental disorders which are a result of incorrect neurological function. And although they may not sound too bad they can take the form of quite severe cases, which can make simple day tasks for a person to be particularly difficult as does depression. Nearly 20% of Britons are affected by these disorders- which can be classified into different types of anxieties depending on symptoms. The types include generalised anxiety disorder, phobias, panic disorder, obsessive compulsive disorder, post traumatic stress disorder, separation anxiety and situation anxiety. These types of disorders can also be found in conjunction with other mental illnesses, including bipolar disorder and depression.
Although anxiety is not a new disorder, having been found in works of Freud and Kierkegaard, characters found in novels of the Victorian Era also exhibit anxiety. It was first noted by Spinoza in the 17th Century, but at that time it was referred to as enslavement to dread. However, it is only recently that anxiety has been recognized as a serious condition. Anxiety can manifest itself in physiological conditions as well, and can cause day to day tasks to become a real burden. As of recent the problem is on a raise and it may due to our modern lifestyle and culture, and other factors that contribute are trauma and genetics (GAD gene). Substance and alcohol abuse have also been linked.
But what makes someone suffer from this? Truth be told, we still don’t quite know. Like other neurological diseases it’s dysregulation of the system, and in particular linked with GABA. People with the condition usually have highly sensitive systems that often react to harmless stimuli.
So what role does GABA play? Well, GABA is an inhibitory neurotransmitter and has been linked to increasing anxiety, hence the first line of drugs used are selective serotonin reuptake inhibitors to counteract the anxious feeling with the feel good hormone. Evidence suggesting the role of GABA was first identified in relation to clinical benzodiazepines and then studied further with neuroimaging and genetic engineering. These act as allosteric modulators of the GABAA receptor; b-carboline and the barbiturates function as direct GABA agonists, thus acting on different part of the GABA system, causing a deficiency in GABA neurotransmission. The fear and anxiety center is found in the amygdale. This information is passed onto the basolateral complex that processes the fear into memory and sensory processing elsewhere. The central nucleus of the amygdala has also been found, in cases of generalized anxiety, to be less distinct with greater gray matter being present. Amygdala areas have decreased connectivity with the insula and cingulate areas that control general stimuli, while having greater connectivity with the parietal cortex and prefrontal cortex
Although cognitive behaviour therapy can be an effective treatment, with anxiety disorders having a close relation to depression the first line of defence is usually antidepressants. As discusses in an article recently published in the New Scientist by Clare Wilson, studies have cast doubt on antidepressants and that these might not be better than a placebo and almost half of the patients do not respond to antidepressants. In the article she question: if the antidepressants do not work, then why are they popular? It is due to withdrawal symptoms. The drugs that should be non addictive are not. Hence, quitting can cause anxiety and insomnia, which are already symptoms of anxiety disorders, alongside other side effects whilst taking the drugs and in some cases are as bad as violent and suicidal thoughts.
According to a new study at Kings College where a blood test has been personalised for the first time for treatment of depression, there may still be some hope for a cure. The test allows scientists to understand whether a person will respond to common antidepressants depending on whether their blood inflammation (measuring MIF and interleukin factors) is above a certain level. There could well be a new way to understand the best course of action for anxiety as well, with new technologies coming our way, and with ways to bring our level of understanding to another level we might just be able to unravel the enigma we call the brain.