Serotonin transporter polymorphism and harm avoidance personality in chronic tension-type headache.

Objective: To investigate the 5-HTT-gene-linked polymorphic region (5-HTTLPR) genotypes and harm avoidance (HA) dimension in chronic tension-type headache (CTH).

Background: Serotonin transporter protein (5-HTT) is a key modulating protein in synaptic serotonergic neurotransmission. Among serotonin gene-linked polymorphism, promoter located in the regulatory region of the 5-HTTLPR has two alleles (short and long) with different transcriptional efficiencies. The HA personality trait may be heritable and associated with serotonergic neurotransmitter activity.

Design: We amplified the 5-HTTLPR by means of polymerase chain reaction and performed genotype polymorphism analyses and we investigated the serotonin-related personality trait by evaluating the HA dimension in tridimensional personality questionnaire (TPQ) in 107 patients with CTH and in 100 healthy controls.

Results: We found an excess frequency of the short allele and a different genotype distribution in patients with CTH. S/S genotype frequency was significantly higher in patients with CTH (76%) than in those with controls (59%; P=.02). Patients with CTH had significantly higher HA scores (21.4+/6.3) than controls (16.3+/-6.1).

Conclusions: This suggests a serotonergic activity might be involved in the development of CTH and 5-HTTLPR might be one of the genetically contributing factors.