Researchers at the Mediterranean Institute of Neurobiology in Marseille, France, using 60 autistic children between the ages of 3 to 11, randomly assigned either a daily dose of a placebo or of bumetanide, a commonly prescribed diuretic to treat heart, lung and kidney conditions.
Several studies suggest that the autistic condition interferes with a neurotransmitter, GABA, that typically puts a damper on neural activity. Bumetanide helps reinforce the inhibiting actions of GABA.
Parents of the children who’d taken bumetanide reported that after 3 months of daily treatment, the children were more “present” and engaged in social interactions than they’d been before taking the diuretic.
Lead researcher, Yehezkel Ben-Ari quantified the parents’ observations on a 60-point scale used to assess behaviors associated with autism, finding that the children had improved 5.6 points, enough to move the group average just under the cutoff for severe autism and into the mild to medium category.
“We have some indications that the symptoms particularly ameliorated with bumetanide are the genuine core symptoms of autism, namely communication and social interactions.”
“It’s enough to make me think about trying it on a few of my autism patients who haven’t responded to other interventions,” says Randi Hagerman, a pediatrician studying neurodevelopmental disorders at the University of California, Davis. He adds that social interactions tend to be reinforcing, so the brain of an autistic child who’s interacting more is likely to reflect more positive development.
A colleague of his, Elizabeth Berry-Kravis, pediatric neurologist at Rush University in Chicago, believes the new study suggests that drugs that reduce neural excitation by blocking substances from neurotransmitters or enhance inhibition by blocking GABA may be helpful for treating autism. “There seems to be this imbalance between excitation and inhibition in people with autism.”
Ben-Ari and his team are preparing for a larger, multicenter trial in Europe.
Sources: SmartPlanet, December 27, 2012 ScienceNOW, December 2012 Study published in Translational Psychiatry December 2012