Friday, 1 March 2013

Five psychiatric disorders are 'linked' through our genes - Why?

Major research has been published that has found genetic 'links' between autism, attention deficit-hyperactivity disorder, bipolar disorder, major depressive disorder and schizophrenia.

The international study compared the genetic codes of 33,000 people with a psychiatric disorder with 28,000 people without a psychiatric disorder. Four genetic variants appeared to increase the risk of all five disorders studied.

There are genetic 'links' between autism, attention deficit-hyperactivity disorder, bipolar disorder, major depressive disorder and schizophrenia. The link between them is also the reason for creativity, mental illness and mysticism in humankind...
How can this be so?

It is difficult for us to see the links between these disorders as we so used to categorising each condition into a separate 'mental illness'. However, if, as researchers are now beginning to do, we look at the genetic links between these mental health problems, a bigger picture soon emerges...

What is the link?

In their new book, Godhead: The brain’s big bang Griffin and Tyrrell look back through historical and prehistorical time to unpick the evolutionary origins of creativity and mysticism and in doing so have also thrown extraordinary light on the evolutionary origins of mental illness and the situation modern humans face today.

The surprising link which connects and explains not only the origins of creativity, mysticism and mental illness but also how farming and civilizations arose, is the brain state associated with rapid eye movements – the REM state. (So named because it is indicated by darting eye movements beneath the eyelids of sleeping mammals, the discovery of which was first published in 1953 by Nathaniel Kleitman and Eugene Aserinsky.)

The REM state

This crucial, often over-looked, brain state is most famously associated with dreaming, because 90% of vividly remembered dreams take place in that state. We spend approximately two hours out of an eight-hour sleep cycle dreaming, during which our senses cease to take in information from the outside world and our anti-gravity muscles are paralyzed so we can’t move. (The pons, a structure on the brainstem, sends signals that shut off neurons in the spinal cord, causing temporary paralysis of the limb muscles. If something interferes with this paralysis, people will begin to physically act out their dreams – a rare, dangerous problem called REM sleep behaviour disorder. A person dreaming about a football game, for example, may blindly kick their sleeping partner while trying to kick the ball in their dream.)

We have provided substantial evidence elsewherethe expectation fulfilment theory of dreams – that all the elements of our dreams are metaphorical pattern matches that act out the suppressed expectations (emotional arousals) that remain in the autonomic nervous system from when we were awake.

How REM relates to genes

But it was the great French sleep scientist Michel Jouvet who first realised that the REM state also performs another function: programming in instincts from our genes. In mammals, brain states associated with REM switch on very early in gestational life. For example, in human foetuses these states have been detected at about 10 weeks after conception. Jouvet first hypothesised that programming of instinctive knowledge in animals takes place when the REM state is activated in the foetus.

Now, thanks to ultrasound video technology, we can observe unborn healthy babies in the womb as young as eight weeks and study their behaviour. From 10 weeks old they can be seen practicing breathing, scratching, grasping, blinking, thumb and toe sucking, sensing other parts of their body and, later, learning the entire range of emotional expression: grimacing, yawning, fear, anger, sadness can all be seen on their faces – and all this happens while they are in the REM state. Although newborns don’t smile until about six weeks after birth, babies in the womb do, perhaps because the womb is less stressful than the loud, bright external environment.

Throughout our life we revisit this process during dreaming in order to preserve the integrity of our instincts by removing any suppression placed upon them during waking. Although programming of instinctive knowledge from our inherited genes, and preserving the integrity of that knowledge, is the prime function of the REM state, we also believe it is key to understanding what enabled us to fulfill the potential of our frontal lobes by accessing two amazing perceptual faculties: imagination (forming mental images of something that is not present to the senses); and universal reasoning (our ability to use critical thinking with all available evidence to reach a rational understanding of the material world and to interpret the actions and intentions of others rationally).

Discovering that imagination has no limits

What we believe occurred about 40,000 years ago is that humans learnt to access the REM dream state while awake. This is quite a logical deduction since we know that the REM state creates a powerful reality simulator in our brain – our dreams are entirely convincing to us. In effect, this simulator is an internal theatre in our mind where metaphorical dramas are enacted.

When we evolved the ability to enter this internal theatre outside sleep and learned to daydream, we became the first animal on Earth with the capacity to ponder over different realities, recreate our past mentally and think about what we might do in the present to influence the material world around us in the future.

Although we call this daydreaming, which has a frivolous connotation of idleness about it, when it is put to good use it is the most productive brain state ever to have evolved. For example, once our ancestors could create different scenarios in their imagination, they had the impetus to develop the complex language they needed to describe their thoughts and feelings. By talking about ideas and things that were not right in front of them, the language of abstract thought opened up. Prior to this, the only need for language was for present-centred signalling sounds, such as warning calls that would direct others to think about whatever was going on in their current environment.

But once possessed of imagination, people could plan, design, reflect, learn and pass on culture. In other words, they could escape the bonds of time and space. Campfire conversations and storytelling would naturally follow, unleashing the power of creativity. The dead would be talked about too, and the realisation that we all must die in our turn invaded human thought. This would naturally lead to pondering the fundamental questions about the meaning and purpose of life, and wondering if we survived death in any way.

Experiencing the wonder of the REM state

Once the power latent within the REM state was released, all the characteristics that we now intimately associate with being human arose. What a wondrous moment it must have been when those pioneers discovered that imagination had no limits.

Like Aladdin they came into possession of a magic cavern full of unlimited treasure, there for the taking: rich and multi-layered language, creativity and craft, stories, music and song, and the world of ideas, reason, philosophical enquiry – and mystical insight. (The REM state is the 'brain portal' through which gnostic insight enters humankind.)

One can still get a sense of the intensity of those prehistoric times by entering the caves, such as Chauvet in France where these trailblazers made beautiful drawings and paintings on the walls and ceilings.

The devastating effects of a single evolutionary leap
 
But, as with Aladdin, such wealth did not come without danger. For example, if we misuse our imagination by worrying, we risk triggering a range of mental illnesses from depression to psychosis.

Just as we believe that what we are dreaming is real while in a dream (unless it is a lucid one, when the sleeper becomes aware that they are dreaming and may influence the dream content), so we believe in the world we see through depressed or anxious eyes. Likewise a person suffering a psychotic episode may believe in the reality of the hallucinated voices or images that he or she hears, and will often act on them.

Since natural mechanisms are precariously dependent on every element working cooperatively in due order, just as a cell needs all its parts to function properly in unison with all the others, it was vitally important that this development maintained itself according to certain procedures.

Whenever conscious access to the REM state was sought, both right and left neocortex had to operate simultaneously, as if two keys needed to be turned together to open a door. If only one key was used without the other, or one wouldn’t turn properly, the result could be disastrous. So learning to operate both keys together was laden with risk.

___________________

To learn more about the link between the major psychiatric disorders, read Godhead: The Brain's Big Bang:
"Read it and act" - Amazon Review

This post was taken from an article on griffintyrrell.co.uk, the author's website.

No comments:

Post a Comment