|Homer's interpretation of the famous painting: 'The Meme"|
Next week I'm giving a presentation to my peers, entitled: 'The Genetics of Schizophrenia'. The topic itself is fascinating to me and not only because of the scientific content. As you may know, there is a large heritable component to schizophrenia and as much as 80% of the liability contributing to the disorder is genetic. Schizophrenia segregates in my family. My mother has been afflicted with paranoid schizophrenia throughout most of her adult life. This has, and continues to have, a profound impact on her life. She has been sectioned on four occasions. The last time, two years ago, she spent 10 months in a secure mental health unit. I was aware of my mother's diagnosis from a relatively early age. My father, when alive, managed my mother's condition with skill and compassion. Only once during his watch was my mother incarcerated and that was when she was first diagnosed.
Behavioural conditions are hard to define from a genetic perspective. Many interacting genes are involved and there is usually an environmental component or trigger. Furthermore, our response to environmental ‘factors’ is very much conditioned by our genetic makeup –thus adding another layer of complexity to an already labyrinthine situation. And then, there are epigenetic phenomena to contend with.......
We are in our infancy concerning the genetic factors involved although several hundred genes have been implicated in schizophrenia. Furthermore, epigenetic changes are also involved. When I was at 'Big school' I was taught the 'Central Dogma Theory'. Basically, this states that genetic information flows in one direction only, from DNA, to RNA, to protein. This means that genetic changes are inviolate from environmental influence. To think otherwise was heretical and akin to the discarded theory of Lamarckism. I've added a link if you would like to know more about this fascinating pre-evolutionary theory. However, relatively recently it has been shown that environmental factors can influence gene expression by a mechanism called 'epigenetic transformation'. Thus, environmental insults can change gene expression, not by mutation within the gene, but by altering DNA conformation or by adding methyl groups to gene promoters. Thus, genes are ‘switched off or on’ according to environmental whim (not really). Clearly, the foetus, and especially the early gestational foetus, is highly responsive to environment changes mediated through the mother. Apart from this 'direct' influence, environmental changes can result in epigenetic changes which alter gene expression in the developing foetus. These changes can have profound affects on the developing baby which often continue to take hold throughout adult life. Moreover, once a ‘genetic imprint’ is achieved, it can be passed down the generations. Many of these changes we would consider maladaptive, especially when they are the consequence of extreme maternal stress or distress. Epigenetic changes, from an evolutionary perspective, are actually adaptive and enable organisms to cope with situations, which otherwise, might result in foetal demise.
Being mad is not all bad news. It has been recognised for a long time that mental illness is associated with creativity and dare I say it, 'genius'. Aristotle, the famed ancient Greek philosopher of the 4th century BC had this to say: "Why is it that all those who have become preeminent in politics or poetry or art are clearly melancholics." But it is only in the past couple of years that we have been able to place this anecdotal observation on a firm scientific footing. Genetic factors predisposing to schizophrenia have been found to be enriched in folk of an 'artistic bent' compared to non-histrionic folk. And conversely, scientists have less of these predisposing factors compared to the general population. Make of this data, what you will.
Schizophrenics, especially when in the throes of acute florid episodes are subject to delusions. During such periods my mother has several very strong delusions and often recurrent delusions. One delusion stands out. She believes that scientists are conducting experiments on her mind, remotely. When my mother is well all the delusions melt away, except one. We were chatting last week and during the conversation she casually announced: 'The Scientists' had been conducting experiments on her the previous night. Generally I don't comment. This delusion has been persistent for many years and no matter what I say, it remains undiminished. However, on this occasion I pointed out the obvious, as I've done many times, previously. She looked me straight in the eye and said: "But my dear Flaxen (not my real name) you would say that, wouldn't you? You are the 'Head Scientist' supervising the experiments"......... Arse