• drug-induced headache;
  • medication;
  • analgesics;
  • headache;
  • epidemiology;
  • specialist consultation

Objective– We studied the frequency of unrecognized headache associated with overuse of analgesic drugs in a population of headache patients treated at a neurological centre. Methods– Patients in North Norway referred to a neurologist for headache during a 2-year period completed a questionnaire. From a total of 945, 262 patients (28%) reported headache 3 days or more per week and used analgesic drugs on a daily bases. Results– A specific diagnoses given by the neurologist was reported in 134 of the patients (51%). Only two patients reported that they suffered from a possible drug-associated headache. Conclusion– This study shows that drug overuse may be the cause of chronic headache in more than 1/4 patients referred to neurologists. Drug-associated headache is a difficult diagnosis which deserves more attention because it is a common and treatable condition.