Relative rates of AD and PDD NOS Study Definition for other PDD ADPDD NOS Ratio Lotter (1966) behaviour similar to 4.1 3.30.8 autistic children Brask (1970) other psychoses or 4.3 1.90.4 borderline psychotic Wing et al (1976) socially impaired 4.9 16.33.3 (triad of impairments) Hoshino et al autistic mental 2.3 2.91.3 (1982) retardation Burd et al (1987) autistic-like 3.3 > 7.82.4 Cialdella & other forms of 4.5 4.71.0 Marmelle (1989) infantile psychosis
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