GAD1 and post-traumatic stress disorder: Cronbach’s alpha of the GPS symptoms score (α = 0.88), PTSD subscale (α = 0.81), depression subscale (α = 0.82) and dissociation subscale (α = 0.76) indicated excellent internal consistency, while the Cronbach’s alpha for subscale disturbances in self-organization (α = 0.39) and GAD (α = 0.49) was poor.