Relationship between suicidal behavior of psychotic inpatients and serotonin transporter gene in Han Chinese

Strong evidence indicates that central serotoninergic system dysfunction is associated with suicidal behavior. The relationship between the serotonin transporter protein (5-HTT) gene of psychotic patients in Han Chinese with suicidal behavior was studied since the 5-HTT plays an important role in serotoninergic transmission. Two hundred and seventy-two psychotic inpatients with suicidal behavior (suicide group) and 275 psychotic inpatients without suicidal behavior (patient control group) were recruited from six mental health facilities in Shanghai, China. Another 628 healthy adults (healthy control group) without suicidal behavior and mental disorder history were enrolled from Shanghai, China. All subjects were Han Chinese. The genotypes and the alleles of 5-HTT genes of the three groups were examined by PCR amplification. Neither the intron 2 variable number tandem repeat (VNTR) polymorphism and 5-HTTLPR (5-HTT gene-linked polymorphic region), nor the haplotype frequencies of this gene have significant differences between the suicide group and the two control groups. However, there was a significant difference in 5-HTTLPR polymorphism between inpatients with a first episode of suicidal behavior and those with recurrent suicidal behavior. Except for the possible heterogeneity between inpatients with a first episode of suicidal behavior and those with more than one, the 5-HTT gene was unlikely to be associated with suicidal behavior of psychotic patient in Han Chinese.