Scientists Move Closer to Understanding Schizophrenia's Cause

Recently, scientists took a significant step toward finding the cause of schizophrenia, in a study that provides the first rigorously tested insight into the genetics behind any common psychiatric disorder. Schizophrenia is a psychiatric disorder characterized by hallucinations and delusional thinking. Although people who suffer from schizophrenia are prescribed drugs, they only hide some symptoms and do not nearly touch upon the underlying cause. 

The recent findings were published in the journal Nature, which explained that although these findings were a step in the right direction, scientists and researchers are not even close to finding the exact cause, and unfortunately, will not lead to any new treatments. But, this new finding will help scientists and researchers move forward in finding the root cause to this ancient disorder, and does explain some mysteries such as why this disorder usually begins in adolescence. 

Researchers put pieces together by which genetics can increase the risk of developing schizophrenia, and found it was linked to synaptic pruning. Synaptic pruning is a process that happens in the brain which sheds weak or redundant connections between neurons as it matures. This happens in the prefrontal cortex, where thinking and planning happens, and starts during adolescence through early adulthood. Researchers suggest that people who carry genes that accelerate synaptic pruning are at a higher risk of developing schizophrenia. They suspect that synaptic pruning goes awry in people with schizophrenia because studies show they have a diminished number of neural connections in prefrontal areas, as compared to people without schizophrenia. 

The research team was made up by scientists from Harvard Medical School, Boston's Children's Hospital and the Broad Institute, a research center allied with Harvard and the Massachusetts Institute of Technology. The team began by focusing on the human genome MHC which was strongly associated with schizophrenia in previous studies. 

The below "skyline" graphs show the genetic variation associated with schizophrenia from 2011 to 2014, while the MHC looms the highest.

The MHC genome is known to control the body's immune responses, which had given rise to the question if schizophrenia is an autoimmune condition. Using advanced statistical methods, the research team found that the MHC locus contained four common variants of a gene called C4 which produced two kinds of proteins, C4-A and C4-B. The team analyzed 64,000 people and came to the conclusion that people with schizophrenia were more likely to have the overactive form of C4-A than the control subjects. C4-A leads to innapropriate pruning in the critical phase of development. Researchers hope to soon determine an at-risk genetic profile for schizophrenia that will help clarify a prognosis for patients. 

The finding of the C4-A gene leading to innapropriate pruning is an enormous step in the process of finding the cause of schizophrenia, and the researchers are excited about this finding. Although they have a long way to go, it gives them more insight into what can be causing this early psychiatric disorder. 

I believe this finding will give researchers motivation to find out more, because this finding has answered many questions and mysteries. We now know what gene is responsible for how fast synaptic pruning happens, but still are not sure why or how this actually happens. This finding also gives researchers ideas on new medications; possibly medications that can interfere with the pruning process. These findings also reveals why schizophrenia shows itself in young people, because that is when synaptic pruning happens, which is very promising. I am surprised, though, that this article does not talk about non-genetic events and if they can have an effect on schizophrenia. Are researchers leaning more towards schizophrenia as a true genetic disorder? Can traumatic events cause schizophrenia? Or maybe worsen effects after a person already has it? There are still many unanswered questions. Although this study did not reveal the cause of schizophrenia, we are well on our way, and technology will only keep advancing to help us through this process.