Table 1.

Summary of First-Episode Schizophrenia-Spectrum MMN Studies

Study	Time of Testing	N (SzS/HC)	Pitch MMN Reduction	Duration MMN Reduction	IQ or Education Controlled	Effect Size at Fz/Fcz (Cohen’s d)
Tested < 1-y FH						Pitch	Dur.
Salisbury et al6,a	<1-y FH	21/27	N		Y	0.09
Oknina et al7	At FH	25/14	N		Y
Oades et al8,b	At FH	28/22		Y	N		1.0
Umbricht et al9,c	<6-mo FH	26/39	N	N	N	0.33	0.25
(College subsample)c	<6-mo FH	12/39	N	N	Y	−0.10	−0.42
(No college subsample)c	<6-mo FH	14/39	Y	Y	N	0.67	0.96
Salisbury et al10,a	<6-mo FH	20/32	N		Y	−0.008
Devrim-Üçok et al11	At FH	30/34	N		Y	0.0
Magno et al12	<3-mo FH	12/27	N	N	U	−0.36	−0.24
Kaur et al13,d	<1-y FE	18/18		Y	N		1.47
Bodatsch et al14	At FE	33/67	N	Y	U	0.11	0.45
Hsieh et al15	<1-y FE	32/56		Y	N		0.50
Mondragón-Maya et al16,f	At FH	20/23	N		Y	0.17
Nagai et al17	<1-y FE	20/22	T	Y	Y	0.34	0.80
Tested < 2-y FH
Kaur et al18,d	First or second episode	20/20		Y	N		1.40
Higuchi et al19,e	<2-y FH	20/20		Y	U		1.60
Higuchi et al20,e	<2-y FH	19/19		Y	U		1.20
Solís-Vivanco et al21,f	<2-y FH	20/23		Y	Y		1.14

Note: FE, first episode; FH, first hospitalization; HC, healthy controls; IQ, intelligence quotient; MMN, mismatch negativity; SzS, schizophrenia spectrum; Y, yes; N, no; T, trend level; U, unreported. Effect sizes: pitch, pitch MMN (left side); dur., duration MMN (right side). Negative values indicate patient samples had larger responses than healthy subjects.

^a–eStudies with matching superscripts present data from overlapping samples. Caution should be used to avoid “double weighting” effect sizes.

^cUmbricht et al performed secondary analyses based on whether FHSz had or had not attended college. Note the strong effect on group differences.

^fSubject overlap between studies is unclear.