trauma exposure, PTSD, and psychosis, our findings of shared genetic risk for PTSD and schizophrenia should be further interrogated with the aim of revealing shared pathophysiological mechanisms and, possibly, new treatments. Regarding treatment, atypical antipsychotics have been used to treat PTSD, though the supporting evidence is controversial.22 In the largest single trial of an adjunctive atypical antipsychotic, risperidone, for PTSD, the drug was superior to placebo for REX (and hyperarousal) symptoms.23 The possibility that a subset of patients with PTSD – possibly those with the greatest shared risk for schizophrenia (or the most prominent REX symptoms) – may be more likely to benefit from antipsychotic medications, should be tested in the drive toward precision medicine in psychiatry.
