DOPAMINE D-2 RECEPTOR (DRD2) GENE AND SUSCEPTIBILITY TO POSTTRAUMATIC-STRESS-DISORDER - A STUDY AND REPLICATION

Subjects on an addiction treatment unit who had been exposed to severe combat conditions in Vietnam were screened for posttraumatic stress d isorder (PTSD). Of 24 with PTSD, 58.3% carried the D2Al allele. Of the remaining eight who did not meet PTSD criteria, 12.5% carried the D2A l allele (p = 0.04). In a replication study of 13 with PTSD, 61.5% car ried the D2Al allele. Of the remaining II who did not meet criteria fo r PTSD, 0% carried the D2Al allele (P = 0.002). For the combined group 59.5% of those with PTSD carried the D2Al allele versus 5.3% of those who did not have PTSD (p = 0.0001). These results suggest that a DRD2 variant in linkage disequilibrium with the D2Al allele confers an inc reased risk to PTSD, and the absence of the variant confers a relative resistance to PTSD.