Association between dopamine beta-hydroxylase polymorphism and attention function in suicide attempters with chronic schizophrenia.

BACKGROUND: Patients with schizophrenia are at a higher risk for suicide compared with the general population. Dopamine beta-hydroxylase (DßH) plays a key role in the conversion of dopamine to norepinephrine, which is related to suicidal behavior and cognitive regulation. OBJECTIVE: To examine whether there is the effect of DßH 5'-insertion/deletion (Ins/Del) polymorphism on cognitive performance in suicide attempters with chronic schizophrenia. METHODS: This polymorphism was detected in 114 suicide attempters and 617 non-suicide attempters with chronic schizophrenia. Cognitive performance was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). RESULTS: The allelic and genotypic frequencies of this polymorphism between two groups did not differ after controlling for covariates (both, p > .05). There were no differences in RBANS scores between two groups after adjusting for covariates (all, p > .05). However, based on the genotype grouping in suicide attempters and non-attempters, the attention score significantly differed after adjusting for covariates (both, p < .05). Further analysis indicated that this polymorphism was associated with attention score in suicide attempters (p < .05), but not in non-suicide attempters (p > .05). CONCLUSIONS: DßH 5'-Ins/Del polymorphism was not a risk locus of suicide attempters, but it was implicated in attention regulation in suicide attempters with chronic schizophrenia.