The best time, in theory, is of course the earlier the better. If a child is born with autism, treatment can be started immediately, but in fact the symptoms of autism are usually recognized only after a certain period of time after the child is born. The characteristics and behaviors of autism usually show up by age three, and parents usually recognize differences between their child and other children around the age of one week, or even earlier. Many parents do not realize that their child is still not talking until he or she is a week and a half old, at which point the parents become anxious and then seek medical attention to get a preliminary diagnosis. However, some parents have the notion that the later the child speaks, the smarter he or she is, so they delay coming to the doctor until the age of two or three, and then it is relatively late to start treatment after the age of three. Parents are advised that if your child does not call mommy and daddy by the age of one week, or if he or she does not ignore you when you call him or her by name, he or she should go to a professional doctor as soon as possible to determine if autism is a possibility, so that some intervention can be done as soon as possible.