‘Our findings suggest that sustained changes in autism symptoms are possible after early intervention, something that has previously been regarded as difficult to achieve,’

said Professor Tony Charman, who led the London arm of the trial and Professor Andrew Pickles, the study methodology expert, both from King’s College London.

‘However, we found no evidence of any effect on child mental health, such as anxiety or challenging behaviours, suggesting that additional interventions may be needed to address these difficulties at later ages. As these children grow up, they will continue to need support in many aspects of their lives. We are currently working to further enhance our intervention.’