Table 2.

Table 2 Large consistent effects from meta-analyses of studies of physical and cognitive examinations of patients with schizophrenia versus controls

	Effect size vs. controls	Different from relatives	Evident at first episode	Specificity vs. bipolar disorder	Other issues
NSS	1.08, but with heterogeneity (Chan et al, 36)	Yes	Yes	Requires more study	Blinding reliability and practicality issues; specific domains and items may have stronger diagnostic properties
IQ	1.10, but with heterogeneity (Heinrichs and Zakzanis, 38)	Yes	Yes, at least in part, but some possible progression	Premorbid IQ deficits may differentiate	Various methods
NSS – neurological “soft” signs