CCKBR and panic disorder: Only 9.2% of 22 alleles from matched normal controls were the CCK-B receptor allele Panic disorders are common in Gulf War Veterans who have been exposed to organophosphate pesticides, nerve agents, high concentrations of n,n-diethyl-m-toluamide (DEET) insect repellants, and toxic levels of pyridostigmine (a cholinergic agonist used to combat nerve agents).