Summary of studies comparing individuals with Asperger syndrome and high-functioning autism (Asperger syndrome groups higher IQ) from Patricia Howlin, Autism and Asperger Syndrome (2004).
| Authors | Year | Criteria | HFA:AS | Conclusions |
|---|---|---|---|---|
| General clinical characteristics | ||||
| Szatmari et al. | 1995 | Modified ICD-10 | 47:21 | HFA > social and adaptive problems, rituals and early language delays. No differences in current non-verbal/communication/motor skills. |
| Eisenmajer et al. | 1996 | Clinical diagnosis | 48:69 | Few differences on any variables, delayed language only significant difference in HFA group |
| Kurita | 1997 | ICD-10 | 16:26 | Few significant differences but HFA > on some CARS items |
| Gilchrist et al. | 2001 | ICD-10 | 13:20 | HFA > ADI problems age 4-5 years. No difference in current functioning on ADI or ADOS. |
| Obstetriclearly history and motor skills | ||||
| Ghaziuddin et al. | 1994 | ICD-10 | 9:11 | No significant differences in motor skills. |
| Ghaziuddin et al. | 1995b | ICD-10 | 9:11 | No significant differences in neonatal optimality scores |
| Ghaziuddin and Butler | 1998 | DSM-IV/ICD-10 | 12:12 | No significant differences in motor skills when IQ controlled for |
| Manjiviona and Prior | 1999 | Modified ICD-10 | 9:12 | AS > PIQ but no differences in motor skills |
| Neuropsychological and language profiles | ||||
| Ghaziuddin and Gerstein | 1996 | ICD-10 | 13:17 | AS > pedantic speech |
| Ehlers et al. | 1997 | Gillberg criteria | 40:40 | Differences in cognitive profiles; AS higher scores on most subtests |
| Pomeroy | 1998 | Non-language impaired PDD | 13:15 | AS > VIQ; also > language comprehension and expression |
| Manjiviona and Prior | 1999 | Modified/strict DSM-IV | 21:35 | AS > VIQ no differences on neuropsychological profiles |
| Miller and Ozonoff | 2000 | DSM-IV | 26:14 | No significant differences in motor skills, executive function or TOM when IQ co-varied. |
| Behavioural and psychiatric problems | ||||
| Ghaziuddin et al. | 1995a | ICD-10 | 8:12 | AS > disorganized thought; few other significant differences |
| Tonge et al. | 1999 | DSM-IV | 75:52 | AS > psychopathology |
| Kim et al. | 2000 | Modified DSM-IV | 40:19 | No differences in depression/anxiety/mood |
Summary of studies comparing individuals with Asperger syndrome and high-functioning autism matched for full-scale IQ
| Authors | Year | Criteria | HFA:AS | Conclusions |
|---|---|---|---|---|
| General clinical characteristics | ||||
| Szatmari et al. | 1990 | Wing's criteria | 17:26 | HFA > social impairments, language problems, stereotypes and preoccupations |
| Mayes et al. | 2001 | Modified DSM-IV | 23:24 | No difference on any of 71 variables (IQ, language, symptomatology, motor co-ordination, emotion or behaviour |
| Ozonoff and McMahon Griffith | 2000 | DSM-IV | 23:12 | HFA > ADI scores at 4; few differences in current scores. No differences in social functioning. AS > special interests HFA > insistence on sameness |
| Obstetric early history and motor abnormalities | ||||
| Szatmari et al | 1989a | Wing's criteria | 25:28 | HFA > early abnormalities in social, language and behavious |
| Gillberg and Gillberg | 1989 | Gillberg criteria | 23:23 | AS > clumsy |
| Neuropsychological and language profiles | ||||
| Szatmari et al. | 1990 | DSM-III | 17:26 | Few differences in IQ profiles, motor or other test scores |
| Ozonoff et al. | 1991 | Modified ICD-10 | 13:10 | AS > VIQ and > VIQ-PIQ difference. AS > verbal memory executive function and TOM scores. HFA > CARS scores |
| Fine et al | 1994 | Wing's criteria | 18:23 | Cohesive discourse > in AS group |
| Klin et al | 1995 | Modified ICD-10 | 19:21 | HFA > PIQ and better motor skills; AS > VIQ and higher verbal ability |
| Iwanaga et al. | 2000 | DSM-IV | 15:10 | No significant differences on gross or fine motor tasks, and most non-verbal tests. AS > HFA on some verbal tasks |
| Klin | 2000 | DSM-IV | 20:20 | No differences on social attribution task |
| Rinehart et al. | 2001 | DSM-IV | 12:12 | HFA > problems in shifting attention |
| Ozonoff et al. | 2002 | DSM-IC | 23:12 | Few differences but AS > VIQ-PIQ different; HFA > expressive problems. No differences on executive function/TOM tasks |
| Behavioural and psychiatric disturbance | ||||
| Szatmari | 1989b | Wing's criteria | 25:28 | HFA > bizarre preoccupations; AS > psychiatric problems |