Table 1.

Group Demographics

	Schizophrenia Patients n = 84			Healthy Controls age-matched to Schizophrenia Patients n = 110			Statistic	p-value	Early Illness Schizophrenia Patients n = 35			Healthy Controls age-matched to Early Illness Patients n = 93			Statistic	p-value	Clinical High-Risk Patients n = 48			Healthy Controls age-matched to Clinical High-Risk Patients n = 88			Statistic	p-value
	n	Mean	SD	n	Mean	SD			n	Mean	SD	n	Mean	SD			n	Mean	SD	n	Mean	SD
Age (years)		29.58	11.57		27.93	9.77	t(192) = −1.08	ns		22.75	5.0		24.62	5.9	t(126) = 1.68	ns		18.93	4.1		19.99	4.3	t(134) = 1.09	ns
Parental SESa,b		39.79	14.85		34.36	15.12	t(190) = −2.45	<.05		40.1	15.2		32.92	14.9	t(126) = −2.44	<.05		36.43	16.4		30.34	13.4	t(134) = −2.33	<.05
Gender							χ2(1, 194) = 4.34	<.05							χ2(1, 128) = 2.5	ns							χ2(1, 136) = .51	ns
Male	64			68					27			58					29			47
Female	20			42					8			35					19			41
Handednessc							χ2(2, 194) = 2.0	ns							χ2(2, 128) = 0.9	ns							χ2(2, 136) = 5.15	ns
Right	75			103					33			87					38			81
Left	6			6					1			5					7			6
Ambidextrous	3			1					1			1					3			1
Schizophrenia subtype
Paranoid	49								18
Disorganized	9								6
Undifferentiated	15								6
Residual	9								3
Schizophreniform	2								2
CHR criteriad
APS																	47
BPS																	2
GRD																	7
Antipsychotic type
Atypical	67								32								0
Typical	6								1								0
Both	5								0								0
None	6								2								48
PANSS total		66.38	16.4							67.34	16.6
SOPS total																		32.3	13.7

Note. SES = socioeconomic status; CHR = clinical high risk; APS = attenuated positive symptoms; BPS = brief intermittent psychotic symptoms; GRD = genetic risk and functional decline; PANSS = Positive and Negative Syndrome Scale; SOPS = Scale of Prodromal Symptoms. Values are given as number of subjects for gender, handedness, diagnostic subtype, clinical high risk criteria, and antipsychotic type. Group means with the standard deviation for age, parental socioeconomic status, PANSS, and SOPS are reported. Age and parental socioeconomic status were analyzed with independent samples t-tests; gender and handedness were analyzed with chi-square analyses.

^aThe Hollingshead (1975) four-factor index of parental SES is based on a composite of maternal education, paternal education, maternal occupational status, and paternal occupational status. Lower scores represent higher SES.

^bSES values are missing from two schizophrenia patients (n = 2).

^cThe Crovitz-Zener (1962) questionnaire was used to measure handedness.

^dClinical high-risk criteria APS, BIPS, and GRD are not mutually exclusive.