A new study, carried out by researchers from China and the UK, suggests that 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 (ASD) and has no significant side effects. Published Monday in the Translational Psychiatry journal, the study demonstrates for the first time that the drug improves the symptoms by decreasing the ratio of the gamma-Aminobutyric acid known as GABA, a neurotransmitter that plays a fundamental role in inhibiting neurons activity throughout the nervous system. People with Autism have lower GABA levels, which mean they have more active neurons that cause the behaviors we usually notice in people with ASD. ASD affects one in 160 children worldwide. It is characterized 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. ASD can be reliably diagnosed at age 24 months or even as early as 18 months of age. 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, 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. In a report released by Cambridges website, Dr. Fei Li from Xinhua Hospital, Jiao Tong University School of Medicine, the clinical lead of the study, said: "We recruited 83 children aged three to six years old and divided them into two groups. A treatment group of 42 children received bumetanide twice a day for three months, while a control group of 41 children received no treatment." Before treatment, both groups had similar CARS (Childhood Autism Rating Scale) scores, which is used to rate behavior such as imitation, emotional response and verbal and non-verbal communication. But afterwards, the treatment group had a better evaluation score compared with the control group.