Depression, schizophrenia and some other mental health conditions can have very different symptoms but they all seem to be connected by a set of structures in the brain.
This network may help us understand the link between certain genes and psychiatric symptoms, and suggests a focus on symptoms, rather than categorising mental health conditions, may be a better way to help people.
鈥淲e know for psychiatric illnesses, the categories of diagnosis are not very reliable,鈥� says Maxime Taquet at the University of Oxford. Psychiatric conditions have been shown to overlap when it comes to which genes they are linked to, as well as symptoms.
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Taquet and his colleagues wanted to find out how these shared genetic factors might influence a person鈥檚 brain structure. Looking at the brains of adults with established disorders might not answer the question, says Taquet, as the disorder or any treatments might have made changes to the brain.
Instead, his team turned to children aged between 3 and 18, none of whom had been diagnosed with a psychiatric condition. Any differences in brain structure among children are more likely to be explained by genes rather than the effects of an established disorder or treatment, says Taquet.
Using data already collected from 678 children in the US, the team started by searching for 1877 genetic factors that have been linked to a range of conditions, including schizophrenia, panic disorder, addiction and others. Each child was given a score based on their overall genetic risk for these conditions.
His team then assessed scans of the children鈥檚 brains. There were 鈥渓arge differences鈥� between the brains of high-risk and low-risk children, says Taquet, and not just in one or two regions of the brain.
Vulnerability network
The team has described the affected regions as being part of a 鈥渧ulnerability network鈥�, which includes three key brain structures.聽The default mode network 鈥� a structure that is active when the brain is at rest 鈥� looks different in children with high scores, for example, as does a structure involved in planning and controlling behaviour.
The brain structure involved in vision was also significantly different in those with high genetic risk scores compared to those with low scores. Taquet presented the findings at the annual meeting of the European College of Neuropsychopharmacology in Copenhagen, Denmark, on 8 September.
The findings highlight the crossover of vulnerability across psychiatric disorders, says Heather Whalley at the University of Edinburgh, UK.
Annika Hulten, a medical advisor for Janssen-Cilag in Helsinki, Finland, says the work is 鈥渋mpressive and promising鈥�. But she cautions that it is too soon to know if this network would make a good target for future treatments. 鈥淚t鈥檚 a stepping stone to other work,鈥� says Whalley.
The findings add weight to the idea that seemingly different mental health conditions have a lot in common, says Taquet. 鈥淭he psychiatric disease categories we have, such as depression, bipolar disorder, schizophrenia and anxiety disorder, are not that different in the end, from a biological point of view,鈥� he says.
