Table 1.

Neurophysiological Markers in Psychotic Disorders

Biomarker	Schizophrenia/Relatives	Bipolar/Relatives	Heritability Estimates	Linkage Findings	Associated gene	Associated Clinical Phenotype
1. SPEM-predictive pursuit	+++/++	+/+	0.7–0.9	6p21	COMT	? Positive symptoms
Pursuit initiation	+/+	−/−				Primary negative symptoms
2. P50	++/+	+/+	0.44	15q14	Alpha-7 nicotine receptor
3. PPI	++/+	+/+	0.32–0.50	22q11a	Neuregulin 1	Positive symptoms
4. P300	++/+	+/+	0.27–0.69	4q22b
5. MMN	++/+	−/−				Negative symptoms; poor functioning
6. Neural synchronization	++/+	+				Positive symptoms

Note: Please see the text for details and appropriate citations. SPEM, smooth pursuit eye movements; COMT, catechol-O-methyltransferase; PPI, prepulse inhibition; MMN, mismatch negativity.

^aBased on findings of abnormal PPI in 22q11 deletion syndrome.

^bBased on a linkage findings in alcoholism.