Drug improves symptoms of autism by targeting brain’s chemical messengers


28-01-2020
back of child's head as he walks away holding parent's hand. Bubbles in the air/ Credit: Life of Pix

Bumetanide – a prescription drug for oedema (the build-up of fluid in the body) – improves some of the symptoms in young children with autism spectrum disorders and has no significant side effects, confirms a new study from researchers in China and the UK.

Published this week in Translational Psychiatry, the study demonstrates for the first time that the drug improves the symptoms by decreasing the ratio of the GABA to glutamate in the brain. GABA and glutamate are both neurotransmitters – chemical messengers that help nerve cells in the brain communicate.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder estimated to affect one in 160 children worldwide. It is characterised by impairments in social communication, which manifest as problems with understanding emotions and with non-verbal communication, such as eye contact and smiling, and in failures to develop, maintain and understand social relationships. People with ASD also tend to have restricted interests and show repetitive behaviour. In mild cases of ASD, people are able to live independently, but for some the condition can be severe, requiring life-long care and support.

Although the biological mechanisms underlying ASD remain largely unknown, previous research has suggested that it may result from changes in brain development early in life, and in particular in relation to GABA, a neurotransmitter, a chemical in the brain that controls how nerve cells communicate. In the adult brain, GABA is inhibitory, which means it switches nerve cells ‘off’. In fetal life and early postnatal development, it is mostly excitatory, switching nerve cells ‘on’ and making them fire, playing a key role in the development and maturation of nerve cells. Alterations in the GABA-switch (from excitatory to inhibitory) can cause a delay in when the developing neural circuits reach functional maturity, with consequences for network activity. This implies that intervening at an early age may help reduce some of the symptoms that can make life challenging for people with ASD.

Current treatments for ASD at preschool age are mainly behavioural interventions, such as using play and joint activities between parents and their child to boost language, social and cognitive skills. However, with limited resources there is an inequality in access to these treatments across the globe, particularly in developing countries.

Previous studies in rats and small clinical trials involving children with ASD suggest that the drug bumetanide, which has been approved for use in oedema, a condition that results in a build-up of fluid in the body, could help reduce symptoms of ASD.

Now, an international collaboration between researchers at a number of institutions across China and at the University of Cambridge, UK, has shown that bumetanide is safe to use and effective at reducing symptoms in children as young as three years old. ASD can be reliably diagnosed at age 24 months or even as early as 18 months of age.

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Image:  Child and parent

Credit: Life of Pix

Reproduced courtesy of the University of Cambridge

 

The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.

University of Cambridge (cam.ac.uk)