Introduction

Top Abstract Introduction Participants and methods Results Discussion References

Headache is the most common somatic complaint in children.¹ Although headache is rare before the age of 4, its prevalence increases throughout childhood reaching a peak at about 13 years of age in both sexes. Estimates of prevalence vary according to age, definition of headache, and method of data collection, but in children of school age as many as 75% may experience headaches infrequently and about 10% have recurring headaches.^2-4

Reports have shown an association between headache in childhood and several psychosocial factors such as depression in the mother, depression in childhood, social disadvantage, and coming from a family with a history of "painful conditions."^5-11 Other reasons suggest that this complaint has a predominantly psychosocial basis. These include a lack of evidence for organic disease in most patients and a high rate of headache with recurrent abdominal pain, another common somatic complaint of children.¹² A recent prospective cohort study followed children with recurrent abdominal pain into adulthood.¹³ As adults they had increased physical symptoms, but these were accounted for by the association with increased rates of psychiatric disorder. Additionally, a recent review of functional somatic symptoms in adulthood suggests that these syndromes share many factors, including psychological distress.¹⁴ It thus seems plausible to speculate that headache in childhood may be associated with an increased risk of both psychological and somatic complaints in adulthood.

Little is known about the long term outcome of headache in childhood. Only one study has followed up children with migraine into adulthood.¹⁵ Overall, 60% of those who had had migraine aged between 7 and 15 years were still experiencing migraine attacks 23 years later, but in half of these patients the attacks were neither as frequent nor as severe as in childhood. No study has yet reported in general on the outcome in adulthood of headache in childhood. Most studies have been cross sectional, often utilising populations of participants in clinical settings. Other prospective studies do not extend beyond adolescence. We aimed to elucidate the childhood associations between headache and psychosocial factors in a sample of the general population and to determine whether headache in childhood is associated with an increased risk of physical and psychiatric symptoms in adulthood. ^{1 2}

	Participants and methods

Top Abstract Introduction Participants and methods Results Discussion References

The national child development study is an ongoing population based birth cohort study. Its origins lie in the perinatal mortality survey that collected data on the births of 17 414 infants born to parents residing in Great Britain between 3 and 9 March 1958, representing 98% of all births. Five subsequent sweeps of data collection occurred at ages 7, 11, 16, 23, and 33. Information was collected from parents, medical staff, teachers, census records, and the participants themselves, by both postal questionnaire and interview. In 1991, 11 407 cohort members were interviewed, representing 69% of the target population. The study has received approval from an ethics committee.

Variables in childhood
HeadacheParents were interviewed when the participants were aged 7 (1965) and 11 (1969). On both occasions they were asked "does your child suffer from frequent headache or migraine?" An ordered categorical variable was created dividing participants into no headache at age 7 or 11, headache at either 7 or 11 only, and headache at both 7 and 11.

Variables in adulthood
Multiple physical symptomsAt age 33 (1991) the participants were asked about specific somatic symptoms: backache, bad headaches, twitching of the face, head, or shoulders, indigestion, upset stomach, heart racing "like mad," pains in the eyes, rheumatism or fibrositis, and worries about health. Only those who endorsed three or more symptoms were deemed to have multiple symptoms. This definition broadly corresponds to the notion of "abridged somatisation,"¹⁷ which is associated with major disability and is probably a clinically relevant level of symptomatology.

	Results

Top Abstract Introduction Participants and methods Results Discussion References

Follow up and representativeness
Overall, 11 407 of the original birth cohort of 17 414 participants were interviewed at age 33, representing 69% of the target population. Complete data for the childhood variables of interest were available for 9841 participants.

Prevalence of headache in childhood
We found a prevalence of headache at age 7 of 8.2% (n=811), which increased to 15.4% (n=1511) by age 11. Most headache occurred in those of a manual social class at both age 7 (manual 75.2% (n=610), non-manual 24.8% (n=201); P=0.03) and age 11 (manual 77% (n=1163), non-manual 23% (n=348); P<0.001).

Associations between headache and other childhood variables
Table 1 shows the associations between headache and other variables in childhood. Those with headache were more likely to have a mother with a chronic physical illness that began before the participant was aged 11, or mental illness in a family member, but there was no significant association with having a father with a chronic physical illness. An association was found between headache in childhood and both depression rating at age 7 and separation from mother for periods of more than one week.

Prospective data
At age 33, 9.3% (n=656) of participants had multiple somatic complaints, 14.1% (n=998) mentioned headaches, and 13.9% (n=972) had evidence of psychiatric morbidity. All three outcomes were more common in women and those from a manual social class. Table 2 shows the relations between other psychosocial variables in childhood and the outcomes in adulthood. Overall, these results show a clear relation between psychosocial adversity in childhood and the three outcomes in adulthood.

	Discussion

Top Abstract Introduction Participants and methods Results Discussion References

Children with frequent headache are at an increased risk of headache and multiple physical and psychiatric symptoms in adulthood. This is the first study using prospectively collected population based data, which confirms that children with headache do not simply "grow out" of their somatic complaint and may also "grow into" others. It is unsurprising that the strongest association was found for headache in adulthood. If common childhood somatic symptoms are regarded as signs of underlying psychosocial adversity and learned illness behaviour from parents, then the persistence of the same symptom into adulthood is plausible.

The pathway from psychosocial factors and somatic symptoms in childhood to somatic and psychiatric symptoms in adulthood remains unclear and needs further investigation. However, taken together, our findings of an association between both headache in childhood and psychosocial factors and headache in childhood and adult morbidity may have implications for the health of today's children and their future wellbeing. We suggest that the wide range of professionals to whom a child with headache may present (including teachers, school nurses and doctors, general practitioners, paediatricians, neurologists, and child psychiatrists) consider the possible role of underlying psychosocial factors in the child's symptoms. If such factors are present and amenable to change, it is possible that intervention may reduce the risk of the child developing symptoms as an adult. This may be even more relevant today than when these participants were children in the 1960s. Evidence shows that the prevalence of headache in childhood is increasing steadily in the developed world,¹⁹ and if this is so there may well be a corresponding increase in somatic and psychiatric symptoms as today's children become adults.

	Acknowledgments

   Contributors: PF and MH formulated the hypotheses. PF performed the analysis and undertook the main writing of the paper. MH participated in discussing core ideas, interpreting the results, and revising the final version. PF will act as guarantor for the paper.

	Footnotes

Funding: None.

Competing interests: None declared.

The full version of this article appears on the BMJ's website

	References

Top Abstract Introduction Participants and methods Results Discussion References

1.	Egermark-Eriksson I. Prevalence of headache in Swedish schoolchildren. A questionnaire survey. Acta Paediatr 1982; 71: 135-140.
2.	Waters WE. Community sudies of the prevalence of headache. Headache 1970; 9: 178-186[Medline].
3.	Larsson BS. Somatic complaints and their relationship to depressive symptoms in Swedish adolescents. J Child Psychol Psychiatry 1991; 32: 821-832[Medline].
4.	Passchier J, Orlebeke JF. Headaches and stress in schoolchildren: an epidemiological study. Cephalgia 1985; 5: 167-176[Medline].
5.	Zuckerman B, Stevenson J, Bailey V. Stomachaches and headaches in a community sample of preschool children. Pediatrics 1987; 79: 677-682[Abstract].
6.	Andrasik F, Kabela E, Quinn S, Attanasio V, Blanchard EB, Rosenblum EL. Psychological functioning of children who have recurrent migraine. Pain 1988; 34: 43-52[Medline].
7.	Cunningham SJ, McGrath PJ, Ferguson HB, D'Astous JD, Latter J, Goodman JT, et al. Personality and behavioural characteristics in pediatric migraine. Headache 1987; 27: 16-20[Medline].
8.	Egger HL, Angold A, Costello EJ. Headaches and psychopathology in children and adolescents. J Am Acad Child Adolesc Psychiatry 1998; 37(9): 951-958[Medline].
9.	Carlsson J. Prevalence of headache in schoolchildren: relation to family and school factors. Acta Paediatr 1996; 85: 692-696[Medline].
10.	Sillanpaa M, Piekkala P, Kero P. Prevalence of headache in preschool age in an unselected child population. Cephalgia 1991; 11: 239-242[Medline].
11.	Oster J. Recurrent abdominal pain, headaches and limb pains in children and adolescents. Pediatrics 1972; 50: 429-436[Abstract].
12.	Borge AIH, Nordhagen R, Moe B, Botten G, Bakketeig LS. Prevalence and persistence of stomach ache and headache among children. Follow-up of a cohort of Norwegian children from 4 to 10 years of age. Acta Paediatr 1994; 83: 433-437[Medline].
13.	Hotopf M, Carr S, Mayou R, Wadsworth M, Wessely S. Why do children have chronic abdominal pain, and what happens to them when they grow up? Population based cohort study. BMJ 1998; 316: 1196-1200[Abstract/Full Text].
14.	Wessely S, Nimnuan C, Sharpe M. Functional somatic syndromes: one or many? Lancet 1999; 354: 936-939[Medline].
15.	Bille B. Migraine in childhood and its prognosis. Cephalgia 1981; 1: 71-75[Medline].
16.	Stott DH. The social adjustment of children. London: University of London Press, 1969.
17.	Escobar JI, Golding JM, Hough RI, Karno M, Burman MA, Wells KB. Somatisation in the community: relationship to disability and use of services. Am J Public Health 1987; 77: 837-840[Medline].
18.	Rutter M, Tizard J, Whitmore K. Education, health and behaviour. London: Longmans, 1970.
19.	Sillanpaa M, Anttila P. Increasing prevalence of headache in 7-year-old schoolchildren. Headache 1996; 36(8): 466-470[Medline].

(Accepted 20 February 2001)