Natural disasters impact brain growth, behaviour: Book

Exposure to severe hurricanes during pregnancy enhances the risk of the unborn foetus to develop autism, according to New Zealand's Victoria University of Wellington researchers, who have shed light on gene-environment interactions in a new book.

In the book "Gene-Environment Interactions in Psychiatry: Nature, Nurture, Neuroscience", Bart Ellenbroek and Jiun Youn from Victoria's School of Psychology say genes are not the only factor that make people more vulnerable to developing a brain disorder.

Gene-environment interactions are usually studied in relation to "rapid" environmental events, which generally induce substantial trauma, says Ellenbroek.

"For instance, there are multiple studies on the influence of natural disasters on the development of brain and behaviour. To give one example, which is described in the book, there is evidence that exposure to severe hurricanes during pregnancy enhances the risk of the unborn foetus to develop autism," Ellenbroek told IANS via email.

"Moreover, the influence of the hurricane depends on when it occurs during pregnancy, with the period in the middle of pregnancy (weeks 17-24) having a much higher risk than before or after that," he said.

However, Ellenbroek says, since climate change is a slow process, he does not expect it to have a strong influence on the developing brain.

The book also delves into the linkages between social behaviour and social communication with regard to brain disorders.

"The link is very strong. Virtually all psychiatric disorders (schizophrenia, depression, anxiety, autism, ADHD) are associated with deficits in social behaviour and social communication. The same can be said for other aspects of behaviour as well, such as emotional instability," said Ellenbroek, who leads the Behavioural Neurogenetics lab at the varsity.

In fact, in the final chapter of the book, the authors have argued that it is "much more important to focus on such 'global' symptoms than on specific brain disorders, as there is a lot of co-occurrence and overlap between different psychiatric disorders".

The book has been published by Academic Press, an imprint of Elsevier

Ellenbroek also highlights the gender bias in psychiatric disorders.

"Although there is still a lot of research that needs to be done, there is a lot of evidence that psychiatric disorders have a gender bias. For instance, depression and anxiety disorders are much more common in females, while autism is more common in males," he said.

He points out many pharmaceutical companies, such as Novartis, Merck, GlaxoSmithKline and AstraZeneca, have all withdrawn (or at least reduced) research in brain disorders.

"The main reason for this is that pharmaceutical research is very costly, and the success rate for drugs in the neuroscience area has been much lower than in other areas (such as dermatology or heart disease)," he added.

--IANS

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