Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
PTSD symptoms
RCT	38 people with chronic PTSD resulting from various non-combat-related traumatic events	Change in PTSD symptoms (mean change in Clinician Administered PTSD Scale) 12 weeks (end of treatment) –52.7 with topiramate (flexible dose: 25–400 mg/day) –42.0 with placebo	P = 0.23		Not significant
RCT	232 people with PTSD resulting from various non-combat-related traumatic events	Change in PTSD symptoms (mean change in Clinician Administered PTSD Scale) 12 weeks (end of treatment) –30.7 with tiagabine (flexible dose: 4–16 mg/day) –30.2 with placebo	P = 0.85		Not significant