The prevalence of chronic daily headache (CDH), and its impact and related medication use or overuse in adolescents were examined at the Neurological Institute, Taipei Veterans General Hospital, and other centers in Taiwan. CDH was defined as headache occurring 15 days/month or more, average of 2 hours/day or more, and for more than 3 months. Of 7,900 subjects, 122 (1.5%) had CDH in the past year. The prevalence was 2.4% in girls and 0.8% in boys (p<0.001). CDH was sub-typed according to ICHD-II criteria as chronic tension-type headache in 65.6% or chronic migraine in 6.6%, and medication overuse CDH in 20%. A majority (67%) of all CDH subjects had some migraine or probable migraine features. Forty one percent consulted physicians, only 1 patient took prophylactic medication, 6 consulted neurologists, 48% reported that school performance was influenced moderately and 21% severely, and only 35% took sick leave for headaches during the past semester. 
COMMENT. While chronic tension-type headache was the most common subtype of CHD in adolescents in Taiwan, a majority had headaches with some features of migraine.
In Turkish adolescents the prevalence of recurrent headache was 45.7%; migraine was diagnosed in 21.3%, and tension-type headache in 5.1%. Recurrent headaches were significantly more frequent in students with low-income families (p=0.016). The 1-year prevalence of chronic recurrent headaches was 21.7%. More than half (53.3%) of the students with headache took medication, and 37.3% saw a physician for headaches.