This thesis describes the results of a large questionnaire-based study on the epidemiology of chronic frequent headache (CFH) in the Dutch adult population. It also includes information on triptan ... Show moreThis thesis describes the results of a large questionnaire-based study on the epidemiology of chronic frequent headache (CFH) in the Dutch adult population. It also includes information on triptan (over)use from the Drug Information Project (GIP database) and the results of a withdrawal trial in General Practice. Lastly, clinical features of children with CFH seen at a tertiary referral centre are presented. The conclusions are as follows: The prevalence of CFH is 4%. CFH is associated with analgesic overuse, psychiatric comorbidity, sleeping problems, smoking, a history of head trauma and low educational level. Female sex is a risk factor for headache, not for chronic headache in particular, and there is no association between oral contraceptive use and CFH. Psychological factors play a role. CFH is associated with catastrophizing, low internal pain control, and high external pain control. Especially catastrophizing seems to be important for the impact of headache on daily life. Personality factors do not pose an additional risk factor for chronification. CFH patients have more overall somatic and psychiatric comorbidity than patients with infrequent headaches. Both high headache frequency and comorbidity contribute to their low quality of life. Medication overuse headache in the general population mainly concerns analgesic overuse. Many use analgesics inappropriately and lack prophylactic medication. Ten percent of triptan users are overusers and account for half of the total costs of triptan therapy. CFH and analgesic overuse also occurs in children and leads to frequent school absenteeism and sleeping problems. An active approach by GP's to identify patients with CFH and analgesic overuse and explain the need for withdrawal is not effective. A letter with discontinuation advice may be effective. Show less