Let’s Talk Mental Health
12th May 2013
We are The Science Show and we need to talk about mental health. This week is Mental Health Awareness Week and its an important issue that will affect almost all of us in some form or another during our lives. Whilst students have shown ourselves to be more open, honest and frank about many things, including sex and mental health, we still find ourselves silenced by unnecessary stigma attached to these important problems.
Here we will be looking at the more scientific areas of mental health disorders. For more information on the more general aspects, please listen to the show 6-7pm on 13/05/2013 or if you missed it find the podcast here.
Introduction to Neurochemstry
The brain is the most complicated machine on Earth. Leading scientists have been searching for years as to the wonders of the thing that gives us consciousness. Yet even with thousands of scientific publications each year, we seem to still be only scratching the surface of least understood part of the human body.
But, like all biological structures, the brain is made up of a wide variety of chemicals that can but looked at quantitatively. However the interdependency of a smorgasbord of amino acids and proteins make neurochemistry one of the hardest disciplines in science to make truly conclusive statements.
And as such, many of the discoveries relating to how the brain works are statistical rather derived from first principals. In this way, scientists perform tests on a large number of volunteers and observe what happens.
From such studies we have discovered much about the neurochemistry of mental health conditions. Some such neurochemistry will be discussed here. However it is important to note that as mental health is such a diverse and complex subject, we cannot say definitively that the changes observed in brain chemistry are a cause or symptom of such
Some of the most important chemicals that travel around our brains are neurotransmitters. As the name suggests, they are the chemical messenger service of the brain, transmitting and relaying instructions between synapses and neurons all over the brain.
Neurotransmitters play a vital role in human behaviour as they control the areas of the brain that respond to stimulation from the outside world.
An example of this is dopamine; whenever you smell food your brain increases production of dopamine. The higher levels of dopamine ‘turn on’ parts of the brain that relate to hunger and eating, making you hungry. We will look at this in more detail later but it shows just how fundamental neurotransmitters are to how you function as a human.
So, once the brain decides to produce more of a certain neurotransmitter in response to some stimulation, the message needs to be received and understood by other chemicals in the parts of the brain that are required. This is where the receptors come in. Each distinct part of the brain has sets of receptors that respond to certain neurotransmitters.
Serotonin is an important neurotransmitter that, like dopamine, relates quite heavily to behaviour. Strangely, the majority of the serotonin in your body is found the gastrointestinal tract and controls intestinal movements.
However the behavioural serotonin that is found in the central nervous system controls many things from mood and feelings of wellbeing to sleep.
It is also a crucial part of the brains ability to judge and adjust appetite. It is the serotonin levels in the different parts of the brain that tells it whether or not it needs food.
Research suggests that variations in serotonin levels play a large part in many mental health disorders including depression and anxiety.
In fact, the link between serotonin levels and behaviour is strong enough that a lot of modern antidepressants are described as ‘Selective Serotonin reuptake inhibitors’ which are thought to actively reduce the effectiveness of serotonin receptors as opposed to simply reducing the amount of serotonin produced. However, again it is important to note that while antidepressants are medically known to work, the qualitative effects of such medication has not been backed up quantitatively, hence the actual way these drugs work is not yet known.
The effects of serotonin and dopamine on behaviour and mood are fundamentally linked. A comparison between the separate influences they have shows only subtle differences between the two. As has been discussed previously, dopamine levels in the brain have been shown to increase in the presence of food.
However this is simply an effect of the more fundamental force that dopamine has on us. It appears to strongly encourage decisive and compulsive behaviour. Not necessarily in a bad way, you would not consider the choice to eat breakfast or not as a particularly compulsive decision, however there is a choice to be made and the dopamine levels contribute to that.
This is slightly different to the effect of serotonin which has the more general influence of deciding whether not food is needed in the first place.
Dopamine also has the predominant role in habit and addiction. It is the ‘reward’ drug of choice that your brain releases when you have made decisions and when you achieve something.
The ‘runner’s high’ that you feel after completing heavy exercise is a good example of dopamine flooding the brain after a task. It is this reward based element that leads to conditional training within the brain, and encourages you to do similar things again in the future. Unfortunately this is directly the effect that addictive drugs such as cocaine us to produce a physical dependence. They force higher concentrations of dopamine to be stored in the dopamine receptors for an extended period of time.
This extra high concentration leads to the feeling of euphoria. And as the receptors are programmed to ‘learn’ from dopamine levels, the brain quickly ‘learns’ that the cocaine is the main source of reward.
Irregular production of dopamine or dopamine transport in the brain has been linked to conditions such as Parkinson’s and Attention deficit hyperactivity disorder (ADHD), this seems logical if dopamine does indeed play such an important role in decision making and impulsiveness.
Eating for a healthy brain
Amino acids are the fundamental building blocks of life on earth. When combined with each other they form all of the different proteins that make up the human body, from muscles and bones to teeth and hair, proteins and amino acids are everywhere.
Essential amino acids are a selection of amino acids that cannot be produced directly in the human body, however they are still required by the body therefore they must come from the diet.
All of the neurotransmitters in the brain are made up of amino acids. And, like the rest of the human body, the source of all these amino acids is the food we eat. Hence, having a diet that is rich in the correct building blocks for neurotransmitters is very important.
For the neurotransmitters that have been discussed previously, the main amino acids associated with production are Tryptophan and Phenylalanine.
Tryptophan is an essential amino acid which is the basis for the production of serotonin. This means that food that have a large amount of tryptophan will naturally produce a stronger serotonin response to food that is ingested.
Phenylalanine is also an essential amino acid but has both positive and negative effects on neurotransmitter production. It is a basis for the production of dopamine. However in larger quantities it reduces the production of serotonin.
We have discussed the difference between serotonin and dopamine in terms of ‘needing food’ and ‘being hungry’, so it follows that the production increase based on the food you eat will contribute to how ‘satisfied’ you feel after eating certain foods.
Fruit and nuts tend to produce quite a bit of serotonin and next to no dopamine; however food such as fried chicken and pizza produces large quantities of both serotonin and dopamine which has the rather unhealthy effect of being satisfying as well as slightly addictive.
Physical exercise is one of the best ways to naturally increase serotonin levels in the brain. It also produces large quantities of dopamine and another neurotransmitter endorphin. The combination of these three acts in a similar way to a lot of antidepressants without any of the unwanted side effects.
In studies of exercise vs. medication for the relief of depression, nearly the same percentage of people felt improved wellbeing after 16 weeks in both cases.
Exercise also has the added benefit of reducing blood pressure and stress, as well as improving overall fitness. The combination of these factors show just how important exercise could be for people suffering with mental health disorders.
If you would like any more information there is a wealth of information on the internet. Many mental health charities provide lots of resources on their own sites.
One of the biggest mental health charities in the country Mind focus on all aspects of mental health
Sane provide practical help for peoples whose lives are affected by mental health issues
Rethink are there to change attitudes towards mental health
A specialist mental health charity for young people
A national student-led mental health foundation
A mental health organisation focusing on eating disorders