Table 2.

The Mean Total IQ and the 12 Subtests of the Wechsler Intelligence Scale for Children (WISC) (at the Mean Age of 15.1 Years) in Relation to Psychiatric Outcome Status 25 Years Later

	SZ-Spectrum (n = 84)	No Diagnosis (n = 127)	Psychiatric Controls (n = 81)	SZ-Spectrum vs. No Diagnosis (df = 209)	SZ-Spectrum vs. Normal Controls Effect Size	SZ-Spectrum vs. Psychiatric Controls (df = 163)	SZ-Spectrum vs. Psychiatric Controls Effect Size
Total IQ	101.6	103.4	100.68	NS	0.14	NS	0.06
Arithmetic	11.4	11.9	11.4	NS	0.22	NS	0.001
Comprehension	14.0	14.7	14.0	NS	0.12	NS	0.001
Digit Span	9.9	9.8	9.7	NS	0.04	NS	0.09
Information	18.3	18.4	17.1	NS	0.04	NS	0.22
Similarities	14.3	14.4	14.0	NS	0.03	NS	0.07
Vocabulary	49.2	50.9	48.6	NS	0.12	NS	0.04
Block Design	33.1	34.6	33.3	NS	0.13	NS	0.02
Coding	45.8	51.2	50.3	0.001	0.41	0.05	0.30
Mazes	16.4	16.2	16.0	NS	0.09	NS	0.12
Object Assembly	24.5	25.6	24.7	0.10	0.27	NS	0.07
Picture Arrangement	29.7	30.7	30.4	NS	0.14	NS	0.10
Picture Comprehension	13.3	13.1	13.2	NS	0.04	NS	0.003

Note: The p-values refer to independent samples t-tests of mean differences between diagnostic categories.