Illicit drug use in cluster headache patients and in the general population: A comparative cross-sectional survey.

Background: The rate of illicit drug use in cluster headache (CH) patients is unknown. Methods: Two hundred and ten CH patients (162 males and 48 females) attending two headache clinics provided information about their lifetime use (once or more in their lifetime, LTU), recent use (once or more in the past year, RU), and current use (once or more in the past 30 days, CU) of illicit drugs. General population data (IPSAD®Italia2007-2008) served as the control group. Results: LTU of each illicit drug but hallucinogens, RU of cannabis, cocaine, amphetamines and ecstasy, and CU of cannabis and cocaine were significantly higher in the male CH patients than in the general population, whereas no difference was found between the CH women and the controls. In the CH group, 28.5\% of patients reported having used illicit drugs for the first time after CH onset and 71.5\% before CH onset. Compared with the controls, the male CH group showed a greater prevalence both of lifetime sustained intensive use of any illicit drug and of current intensive use of cannabis. Conclusion: The results of this study indicate that male CH patients are prone to overindulge in illicit drug use. This finding possibly reflects a common biological susceptibility that predisposes these subjects to CH and to addictive behaviour.