title: Reply to: 'illicit drugs and cluster headache: an inevitable discussion'.
authors.forename: John H
authors.initials: JH
authors.lastname: Halpern
mesh_terms: D003027:Cluster Headache / Q000453:epidemiology*; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D019966:Substance-Related Disorders / Q000453:epidemiology*
chemical_list: D013287:Illicit Drugs