Trazodone is not FDA-approved for PTSD, but it is sometimes used off-label, including specifically for nightmares associated with the condition, given its sedating properties and effect on sleep architecture. It is one of several medications considered in this context, alongside options like prazosin, which has more specific evidence for PTSD nightmares.
Treatment decisions for PTSD symptoms, including nightmares, should involve a clinician experienced in trauma-related care, since PTSD treatment usually also involves therapy approaches alongside any medication.