Headaches and psychopathology were evaluated in 1013 children, aged 9 to 15 years, enrolled in the Great Smoky Mountains Study, and reported from Duke University Medical Center, Durham, NC. Headaches lasted at least 1 hour and occurred each week during the 3 months prior to interview. The overall prevalence of headaches was 10.3% (10.4% of boys and 10.2% of girls). An increased prevalence with age was similar in boys and girls and did not affect associations with psychiatric disorders. Of those with internalizing disorders, depression and anxiety, 20.5% had headaches, compared to 9.2% in children without psychiatric disorders. Girls were affected more than boys (30.6% v 13.1%). Of externalizing disorders, conduct disorders were associated with a 2-fold increase in prevalence of headache only in boys, whereas ODD and ADHD did not predispose to headaches. Although ODD in girls was not associated with an overall increase in headache prevalence, this comorbidity resulted in an impaired quality of life, with headaches that were more prolonged, affected school attendance, and required greater medical intervention. 
COMMENT. Depression and anxiety disorders are associated with an increased prevalence of headache in girls, and conduct disorders predispose to headaches in boys. Girls with ODD have greater morbidity resulting from headaches, with increased school absences and medical intervention. The authors discuss the common neurotransmitter, serotonin, in the regulation of headaches, depression, anxiety, aggression, and hostility, and the relation to Carroll’s theory of central pain mechanisms as a cause of depression.
Classification of Headache. Cluster analysis failed to identify groups of symptoms corresponding to the World Federation of Neurology definition of migraine in 150 children with recurrent headache, attending neurology clinics at Royal Manchester, Booth Hall, and Birmingham Children’s Hospitals, UK. Three groups of symptoms that were identified were not stable, not clinically useful, and did not correspond to any of the International Headache Society classifications. The authors propose a continuum theory of headache disorders based on signs and symptoms associated with the headache, course, response to treatment, and prognosis, rather than the severity and character of the headache itself.