It is impossible to cure autism with the methods known today. At the same time, sometimes remission occurs in childhood, leading to withdrawal of the diagnosis of autism spectrum disorder; this sometimes happens after intensive care, but not always. The exact rate of recovery is unknown; in unselected samples of children with autism spectrum disorders, rates range from 3% to 25%. Most children with autism lack social support, strong relationships with others, career prospects, and a sense of self-determination. While underlying problems remain, symptoms often subside with age.

There are few qualitative studies devoted to long-term forecasting. Some older autistic people show moderate improvements in communication, but a fair number of these skills deteriorate; there is no study that analyzes the condition of autistic people over middle age.

The development of language skills before the age of six, an IQ level of over 50 units and the presence of a profession or skill in demand are signs that predict the best performance in the future; a person with severe autism has a low chance of achieving independence. In a 2004 British study, of a group of 68 autistic people diagnosed as children before 1980 with IQs above 50, only 12% achieved a high level of independence by adulthood, 10% had several friends and were busy most of the time, but required some support, 19% had some degree of independence but tended to stay at home and needed significant support and day-to-day supervision, 46% needed the care of an autism specialist, increased support and only a little autonomy, and 12% needed a highly organized hospital care. According to Swedish data from 2005, in a group of 78 autistic adults matched with no IQ cutoffs, the results were worse: for example, only 4% lived an independent life. In a Canadian publication, an analysis of the condition of 48 young people with autism spectrum disorders diagnosed in preschool age identified subgroups with poor (46%), moderate (32%), good (17%) and very good (4%) levels of functioning; 56% of them have had a job at least once in their life, mostly volunteer, adapted or part-time.

Changes in diagnostic practice, as well as the increased availability of effective early intervention methods, call into question the applicability of the above data to children currently being diagnosed.