Journal of Korean Neuropsychiatric Association  2008;47(2):142-152

Association Between Suicide Attempts in Patients With Depressive Disorder and Tryptophan Hydroxylase A218C Polymorphism.

Se Hoon SHIM 1 ; Bo Young HWANG ; Young Joon KWON ; Hee Yeon JUNG ; Bun Hee LEE ; Yong Ku KIM

Affiliations

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Keywords

Suicide; Tryptophan hydroxylase (TPH); Depression; Association study

Country

Republic of Korea

Language

Korean

Abstract

OBJECTIVES: Several lines of evidence suggest the serotonergic dysfunction involved in the biological susceptibility of suicide. Tryptophan hydroxylase (TPH), the rate-limiting enzyme in the biosynthesis of serotonin, plays a vital role in serotonin metabolism. In a case-control study, we investigated whether the TPH gene was a susceptible factor for suicidal behavior in depressive patients. METHODS: The subjects were 218 depressed patients who attempted suicide and visited emergency rooms in multi-medical centers. One hundred thirty hospitalized non-suicidal depressed patients and the 161 normal controls were matched with the suicidal group. Individuals in all 3 groups were evaluated independently by a Structured Clinical Interview for the purpose of establishing a DSM-IV criteria diagnosis (SCID). The severity of depressive symptoms was evaluated using Hamilton depression rating scale (HDRS). RESULTS: There was no significant difference in genotype distributions and allele frequencies of TPH intron 7 A218C polymorphisms among 3 groups. Furthermore, no significant difference in genotype counts and allele frequencies of the polymorphisms was found among lethal suicidal depressed patients, non-suicidal depressed patients and the normal controls. CONCLUSION: This study suggests that the A218C polymorphism of the TPH gene is unlikely to have a major effect on the susceptibility of suicidal behaviors in depressive patients.