Table III. Effect of a family history of suicide. SA: suicide attempt; NS: nonsignificant.

	Probands with a blood relative suicide victime	Probands with a first-degree relative suicide victim	Probands with a second-and third-degree relative suicide victim
Schizophrenic patients versus normal controls
Schizophrenic patients	18.1% (29)	5.6% (9)	13.1% (21)
Normal controls	11.8% (12)	0%	11.8% (12)
Significance	NS	P=0.008	NS
Schizophrenic attempters versus schizophrenic nonattempters
With a history of SA	26.2% (21)	7.5% (6)	20% (16)
Without a history of SA	10% (8)	3.7% (3)	6.2% (5)
Odds ratio	3.2	2.1	3.7
95% confidence interval	(1.4-7.6), P=0.008	(0.5-8.4), NS	(1.4-10.3), P=0.01