Doctors have long believed that disabling autistic disorders last a lifetime, but a new study has found that some children who exhibit signature symptoms of the disorder recover completely. The study, posted online ... by the Journal of Child Psychology and Psychiatry, is the largest to date of such extraordinary cases and is likely to alter the way that scientists and parents think and talk about autism, experts said. The findings suggest that the so-called autism spectrum contains a small but significant group who make big improvements in behavioral therapy for unknown, perhaps biological reasons, but that most children show much smaller gains. Deborah Fein of the University of Connecticut at Storrs recruited 34 people who had been diagnosed before the age of 5 and no longer had any symptoms. They ranged in age from 8 to 21 years old and early in their development were in the higher-than-average range of the autism spectrum. The team conducted extensive testing of its own, including interviews with parents in some cases, to gauge current social and communication skills. On measures of social and communication skills, the recovered group scored significantly better than 44 peers who had a diagnosis of high-functioning autism or Asperger's syndrome. Dr. Fein emphasized the importance of behavioral therapy. These people did not just grow out of their autism," she said. "I have been treating children for 40 years and never seen improvements like this unless therapists and parents put in years of work."