Table 1.

Sample Characteristics of 305 adults with DSM-III or DSM-IV diagnoses of ASD eligible for participation in the current study.

Sample	Participants1	Nonparticipants2	Total Eligible
N	162	143	305
Mean age at Time 1 (years)	7.5	7.6	7.5
Mean age at Time 2 (years)	35.4	33.9	34.6
Male:Female ratio	3.0:1	2.5:1	2.8:1
Reclassified ASD (N)	22	42	64

¹Excludes a random set of 7 first- or second-degree blood relatives for whom data were collected to ensure independence of data.

²Unable to contact or declined to participate.