Tyrosine hydroxylase allelic distribution in suicide attempters.

A tetranucleotide repeat polymorphism in the first intron of the tyrosine hydroxylase (TH) locus was examined in a group of 118 adult suicide attempters and 78 control subjects. The suicide attempters were diagnosed according to DSM-III-R criteria at the index attempt and represented the following diagnoses: major depression (18), dysthymia (13), anxiety disorders (16), adjustment disorders (29), psychoactive substance abuse disorders (27) and psychotic disorders (15). A significant variation in the prevalence of carriers of the TH-K3 allele (high for suicide attempters with adjustment disorders, P = 0.0023) and a tendency toward a variation of the TH-K1 allele (low among all suicide attempters, P = 0.046) was observed. In light of other data the variation of TH-K1 and TH-K3 suggests that these alleles may reflect predisposition for a common phenotype with altered vulnerability for psychiatric disorders.