Landmark discovery made on the cause of schizophrenia
Researchers have made a genetic discovery which suggests a likely cause of schizophrenia, and the finding may have huge implications for early detection and treatment of the illness.
A new study published in the prestigious scientific journal Nature has found that an individual's risk of developing schizophrenia increases if they inherit specific gene variants involved with a process known as "synaptic pruning".
Synaptic pruning is a normal part of development where extra neurons in the brain are eliminated as a way to improve its efficiency. It's a complicated process, but you can imagine it by thinking of the brain as a system of telephone wires that communicate with one another, linking together different parts. These "wires" are synapses.
When a baby is born, they are inundated with a huge amount of sensory information. That information needs to then be linked to other regions of the brain responsible for processing it. When parts of the brain are linked, it establishes direct pathways. Infants create many of these. At birth, humans have around 2,500 synapses per neuron. By age 3, they will have 15,000.
This is more than necessary. The brain is inefficient if there are so many wires, particularly if some aren't used. Over time, some of our neural pathways strengthen. However, those less useful pathways get deleted. By the time we're adults, most of us will have about half as many neural connections as we did as 3-year-olds.
The study, which comes from Harvard Medical School, suggests that people with schizophrenia mark too many synapses for deletion during adolescence because of a genetic variant. Their excessive synaptic pruning leads to an abnormal loss in grey matter in the brain, a characteristic that has been observed in schizophrenia patients for 20 years.
What's new about this study is that it's the first time schizophrenia has been linked with the presence of a specific genetic variant. Steven Hyman, director of the Stanley Center for Psychiatric Research at the Broad Institute at MIT, told The Washington Post that the findings come from "the most significant mechanistic study about schizophrenia ever".
"I’m a crusty, old, curmudgeonly skeptic, but I’m almost giddy about these findings", he enthused.
The implications of the findings could be enormous for the 25 million people in the world who have schizophrenia — as well as their friends and families. It could make room for early detection of the disorder, and it could pave the way for new treatments. As it stands, treatment for schizophrenia is geared towards managing existing symptoms. But with information about the cause of schizophrenia, researchers may be able to address the underlying contributing factors.
Schizophrenia is a mental illness which can make it difficult for individuals to distinguish between what is real and what isn't. It can also involve difficulties in thinking clearly, relating to others and managing emotions. Symptoms vary considerably between individuals, but paranoia and other delusions, hallucinations, disorganisation in speech and behaviour and an apathetic or unemotional demeanour are some experiences which characterise the disorder.
The symptoms of schizophrenia can be very disruptive to regular functioning. But so too can the stigma which surrounds the diagnosis. A 2012 survey conducted by the independent "Inquiry into the Schizophrenia Label," involving around 500 people who have been diagnosed with schizophrenia, found that more than 80 per cent said the diagnosis made life more difficult; 88 per cent said they thought the public associated schizophrenia with violence.
This new finding is important because it offers some hope for people who may be struggling with their illness. But it's also important in that it sheds some much-needed light on a misunderstood population.
If you need advice, information or support regarding schizophrenia or any other type of mental illness, contact mental health charity Mind.