Understanding Neurobiology and Treatment

From the Ancient Greek philosopher Hippocrates stating that the brain is the seat of intelligence, to Andreas Vesalius discovering the pineal gland and drawing the corpus stratum[1], humans have been attempting to understand the most complex organ in the body, the brain, for thousands of years. The brain is made up of around 86 billion neurons, which communicate to form circuits[2] and share information. It is the command centre of the body, and is responsible for sending and receiving messages from the senses to the body and organs.

Our understanding of neurobiology has grown a great deal in the previous century, and is set to expand exponentially in the future. As with any organ, disruption in the brain’s activity and make-up can cause it to function incorrectly. It is now widely thought that addiction and mental illnesses can result from this. This article will seek to explain how the brain works with regards to mental illness and addiction, and will outline various methods used to treat these and their neurological implications.

It is important to note that there are many different theories on how addiction and mental illnesses develop, and due to the relatively imprecise nature of neuroscience as it is now, it is difficult for scientists to agree on one particular causative factor. The understanding of these various causes has also been heavily debated over the years.[3] It is also thought that addiction and mental illnesses can be caused by a variety of factors, such as genetics[4], which means that treatment must be highly personalised to the individual.

It is thought that addiction and mental illnesses can stem from the brain experiencing trauma, caused by prolonged or severe periods of stress. This is especially true at a young age, as the brain is still developing[5]. It is said that 16% of children who undergo trauma will go on to develop Post-Traumatic Stress Disorder[6], which can increase the risk of addiction, self-harm, depression, and anxiety. It is thought that stress can affect the dopaminergic system, which is the body’s ‘reward’ system[7]. Prolonged exposure to this can cause a ‘dampening’ of this dopamine system, meaning that subjects are less responsive to dopamine [8]. It is thought that people can be genetically predisposed to this phenomena[9].

Many popular drugs of abuse, such as heroin, cocaine, and methamphetamine, are known to cause a massive release of dopamine[10]. It is thought that over time, the brains reward pathways are ‘rewired’, in that the dopamine receptors become increasingly insensitive to dopamine, leading the user to compulsively consume increasing amounts of drugs to receive the same effect[11].

The brain’s ability to change and re-organise its structure according to stimuli is known as ‘neuroplasticity’[12] which, fortunately, can work both ways in terms of addiction and mental health. It has been shown that the parts of the brain responsible for impulse control recovered somewhat in the brains of long-term abstinent alcoholics[13]. Changes in the brain have also been observed in those who have been abstinent in the short term[14]. Heavy alcohol use is associated with a loss of grey matter, though it has been shown to start recovering after three weeks of abstinence[15].

There are many different therapeutic and pharmacological approaches to achieving abstinence in order to allow the brain to ‘re-wire’ its dopaminergic system and recover to normal levels. Cognitive Behavioural Therapy has been shown to help clients to address and process trauma[16], and has also been shown to aid users in recovering from addictive behaviour[17]. Eye Movement Desensitisation Reprocessing (EMDR) is based on the theory that our brains can heal faster during periods of Rapid Eye Movement (REM). During this treatment, the therapist makes movements which encourage the body to mimic REM, whilst encouraging the client to explore their trauma in a controlled environment. This has also been shown to be effective in addiction recovery[18].

Selective Serotonin Reuptake Inhibitors (SSRIs), such as Citalopram and Sertraline, are used in both recovery from addiction[19] and to remedy mental health conditions such as depression and anxiety[20]. This is thought to aid these processes as these drugs aim to restore serotonin to natural levels. It is important to note that mental illnesses have many purported causes[21], and the role of SSRIs in recovery is controversial[22]. One study found that SSRI treatment increased blood brain-derived neurotrophic factor (BDNF), which is a factor used to measure neuroplasticity. The levels of BDNF also seemed to correlate positively with depression score levels following treatment, which suggests recovery from depression is associated with neuroplastic changes[23]. These findings are compounded by a study which claimed that depression correlates with lack of neuroplasticity, with these drugs being effective by correcting this function[24].

Technology is developing which enables scientists to accurately map and analyse areas of the brain in great detail[25]. These breakthroughs mean that new theories on addiction and mental health treatment are being discovered and tested every year, making it one of the most exciting potential areas in the field of recovery.


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