ASD is a lifelong neurodevelopmental condition with a highly variable clinical course throughout childhood and adolescence.[123]Baird G, Cass H, Slonims V. Diagnosis of autism. BMJ. 2003 Aug 30;327(7413):488-93.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC188387
http://www.ncbi.nlm.nih.gov/pubmed/12946972?tool=bestpractice.com
In general, people with ASD with a higher IQ and language ability in childhood tend to have fewer and less severe symptoms of ASD in adulthood, and are more likely to live independently.[320]Magiati I, Tay XW, Howlin P. Cognitive, language, social and behavioural outcomes in adults with autism spectrum disorders: a systematic review of longitudinal follow-up studies in adulthood. Clin Psychol Rev. 2014 Feb;34(1):73-86.
http://www.ncbi.nlm.nih.gov/pubmed/24424351?tool=bestpractice.com
However, in high-functioning adults with ASD, better reported quality of life is associated more with family and community support than the extent or severity of core ASD symptoms.[321]Renty JO, Roeyers H. Quality of life in high-functioning adults with autism spectrum disorder: The predictive value of disability and support characteristics. Autism. 2006 Sep;10(5):511-24.
http://www.ncbi.nlm.nih.gov/pubmed/16940316?tool=bestpractice.com
Around 9% of children diagnosed with ASD in early childhood no longer meet diagnostic criteria by early adulthood.[322]Brignell A, Harwood RC, May T, et al. Overall prognosis of preschool autism spectrum disorder diagnoses. Cochrane Database Syst Rev. 2022 Sep 28;9(9):CD012749.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012749.pub2/full
http://www.ncbi.nlm.nih.gov/pubmed/36169177?tool=bestpractice.com
These people are more likely to have higher cognitive skills at age 2, and to have participated in early intervention services.[323]Anderson DK, Liang JW, Lord C. Predicting young adult outcome among more and less cognitively able individuals with autism spectrum disorders. J Child Psychol Psychiatry. 2014 May;55(5):485-94.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819743
http://www.ncbi.nlm.nih.gov/pubmed/24313878?tool=bestpractice.com
Some children may receive a change in diagnosis, for example from ASD to ADHD or obsessive compulsive disorder. This is more likely in children diagnosed with ASD before 30 months of age.[324]Zwaigenbaum L, Bauman ML, Fein D, et al. Early screening of autism spectrum disorder: recommendations for practice and research. Pediatrics. 2015 Oct;136 Suppl 1:S41-59.
http://www.ncbi.nlm.nih.gov/pubmed/26430169?tool=bestpractice.com
Many adults with ASD require lifelong full-time care. About 15% of adults with ASD will live independent lives, whereas 15% to 20% will live alone with community support.[123]Baird G, Cass H, Slonims V. Diagnosis of autism. BMJ. 2003 Aug 30;327(7413):488-93.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC188387
http://www.ncbi.nlm.nih.gov/pubmed/12946972?tool=bestpractice.com
One meta-analysis found that, in a sample of 828 individuals with ASD, 19.7% had a good long-term outcome, 31.1% a fair outcome, and 47.7% a poor outcome, in terms of global measure of adjustment.[325]Steinhausen HC, Mohr Jensen C, Lauritsen MB. A systematic review and meta-analysis of the long-term overall outcome of autism spectrum disorders in adolescence and adulthood. Acta Psychiatr Scand. 2016 Jun;133(6):445-52.
http://www.ncbi.nlm.nih.gov/pubmed/26763353?tool=bestpractice.com
Among individuals with ASD who have complex neurologic/medical and neuropsychiatric comorbidities, there is evidence of a twofold higher mortality risk through young adulthood.[326]Schendel DE, Overgaard M, Christensen J, et al. Association of psychiatric and neurologic comorbidity with mortality among persons with autism spectrum disorder in a Danish population. JAMA Pediatr. 2016 Mar;170(3):243-50.
http://www.ncbi.nlm.nih.gov/pubmed/26752506?tool=bestpractice.com