ADCYAP1 and migraine disorder: Ample human experimental data support the involvement of PACAP-38 in cephalic pain.12,15,16 In a randomized, double-blind, placebo-controlled, two-way crossover trial,12 intravenous infusion of PACAP-38 induced migraine attacks in seven (58%) of 12 participants with migraine, compared with none after placebo.