The prevalence of migraine and other headaches in 7-year-old children, in 1974 and 1992, was determined by school physicians at the time of medical examinations, using the identical study design and a similar urban child population of the same age group, and the data analysed in the Department of Child Neurology, University of Turku, Finland. The prevalence of “present” headache at age 7 years, defined as headache occurring in the preceding 6 months, increased from 14.4% in 1974 to 51.5% in 1992. Boys and girls were affected similarly. “Past” headache, having occurred at any time prior to present headache, also showed a significantly increased prevalence from 23.4% of children affected in the 1974 study to 71.1% in 1992. In both present and past headache categories, those having headaches infrequently, less than once a month or yearly, showed the greatest increase in prevalence. Precipitating factors, fever, fatigue, and head trauma, were equally prevalent in 1974 and 1992. Migraine headache had also increased from 1.9% affected in 1974 to 5.7% in 1992. Migraine prevalence was especially high in city areas with high percentages of council houses and family relocations. 
COMMENT. The prevalence of headache, including migraine, has increased significantly in school age children living in an urban area in Finland, in an 18 year period from 1974 to 1992. Highest increases occur among children exposed to social instability and stress. Similar increases in headache prevalence are known to have occurred in adults in the United States in the 1980s. (see Progress in Pediatric Neurology II, PNB Publ, 1994, ppl53-155).
The Children’s Headache Assessment Scale (CHAS), a parent questionnaire focusing on situations and events surrounding the headaches, emphasizes stress antecedents and coping responses rather than symptom details, and is of value in following responses to behavioral therapy. Environmental factors, including nutrition, are important in the etiology and management of childhood headache and warrant further study. (see Progress in Pediatric Neurology I, 1991, ppl41-150).