[Suicide attempt, psychopathology and genetics].

BACKGROUND

There is compelling evidence that suicidal behaviour has a heritable component and is associated with disturbances in serotonergic mechanisms. Thus genes coding for proteins of the serotonergic pathways are leading candidates for investigating possible associations.

METHOD

We studied three serotonergic gene polymorphisms (5-HTTLPR S/L, TPH A779C, 5-HT1B G861C) in a sample of 114 unrelated suicide attempters (mainly non-violent methods), in 112 patients, 23 siblings and 56 healthy controls. Genotyping was done using polymerase chain reaction (PCR) based assays. The primary analyses compared allele and genotype frequencies between patients and controls and to test for presence of linkage disequilibrium using the family based association test (FBAT). The genotypes were further related to clinical characteristics and to psychological traits.

RESULTS

There was a trend towards an increase in the L-allele frequency of the 5-HTTLPR in suicidal patients (p=0.066, OR=1,57, 95%CI 0,96-2,52). No other polymorphisms were associated with suicidal behaviour and the FBAT showed no excess transmission of any allele from parents to the offsprings. We found a slight reduction in "Novelty Seeking Scores" in patients having at least one S-allele (one-way ANOVA F=3,90, p=0.024). All the other traits were not related to any of the genotypes.

CONCLUSION

Our data extend the evidence that genetic factors do not play a major role in non-violent suicidal behaviour. The 5-HTTLPR S/L variants may have an impact on personality traits.