Headache and Psychological Functioning in Children and Adolescents
From the Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH (Dr. Powers); Department of Psychology, Columbus Children's Hospital, Columbus, OH (Dr. Gilman); Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH (Dr. Hershey); and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH (Drs. Powers and Hershey).
Address all correspondence to Scott W. Powers, Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 2015, Cincinnati, OH 45229-3039.
Headache can affect all aspects of a child's functioning, leading to negative affective states (eg, anxiety, depression, anger) and increased psychosocial problems (for instance, school absences, problematic social interactions). For children and adolescents who experience frequent headache problems, comorbid psychological issues are a well-recognized, but poorly understood, clinical phenomenon. The confusion surrounding the relationship between pediatric headache and psychopathology exists for several reasons. First, in some cases, headache has been inappropriately attributed to psychological or personality features based on anecdotal observations or interpretations that go beyond the available data. Additionally, measures of psychopathology have not always adhered to the American Psychiatric Association's diagnostic criteria, thus reducing the reliability of diagnostic judgments. Furthermore, the diagnosis of headache has not always followed standard criteria, and has been complicated by the emergence of new terms and evolving measures. Finally, methodological shortcomings, such as incomplete descriptions of the procedures and criteria used for the study, inadequate descriptions of headache severity, lack of a control group for comparison with individuals without headaches, reliance primarily on cross-sectional research designs that are often discussed with inferences to causal hypotheses, and the use of unstandardized assessment measures, have significantly limited the validity of research findings. The goal of the current review is to examine the extant literature to provide the most up-to-date picture on what the research has made available about the magnitude, specificity, and causes of psychopathology in children and adolescents with headache, in an effort to further elucidate their relationship and prompt a more methodologically rigorous study of these issues.
For many children and adolescents, headaches are a common phenomenon.1 In fact, headache is the most frequently reported pain among children and adolescents.1–3 A recent survey of chronic pain in youth found that 18.9% of respondents from the general pediatric population reported recurrent headache as the most prevalent chronic pain.4 Although headache is rare before the age of 4 years, its prevalence increases throughout childhood, reaching a peak at about 13 years of age in both males and females.5 Estimates of prevalence vary according to age, definition of headache, and method of data collection; but among school children, as many as 65% to 75% may experience headaches infrequently1,6 and about 10% suffer from recurring headaches (at least once per week).7,8 According to data recently obtained from the National Health Interview Survey, more than 3.7 million children (6.7%) aged 4 to 17 years in the United States had notable headache pain over a 12-month period of time.9 This is significant, as recurrent headaches in childhood may be a precursor to potentially severe headache syndromes later in life.
Headache has been associated with psychiatric illness, such as anxiety and depression, for more than a century. Headache can affect all aspects of a child's functioning, leading to negative affective states (eg, anxiety, depression, anger) and increased psychosocial problems (eg, school absences, problematic social interactions).10,11 Major flaws in research, such as the use of clinic samples which are not representative of all children and adolescents with recurrent headaches, interpretations that go beyond the data, such as over-pathologizing children despite scores on psychological instruments in the normal range, and neglecting to use valid, standardized instruments or established diagnostic criteria (eg, Diagnostic and Statistical Manual of Mental Disorders [DSM]) for diagnosis of psychopathology limit understanding of the relationship between headache and psychopathology.12–14 Thus, for children and adolescents who experience headache problems, comorbid psychological issues are a well-recognized, but poorly understood, clinical phenomenon.12
In the child and adolescent literature, the relationship between headache and psychiatric symptoms has not been well-defined. Depression and anxiety disorders are thought to be particularly problematic psychological correlates of recurrent headaches. Among adults, several epidemiological and clinical studies have reported an association between headache and depression.15–20 Anxiety disorders have also been consistently associated with recurrent headache among adults.21,22 The apparently high comorbidity of headache and depression and anxiety has generated substantial attention in the pediatric headache literature.
The goal of the current review is to examine the extant literature to provide the most up-to-date picture on what the research has made available about the magnitude, specificity, and relationship between psychopathology in children and adolescents with headache in an effort to further elucidate their relationship. Methodological considerations within this literature will be discussed; recommendations for future research are also presented. Finally, based upon the current evidence, this review will discuss clinical implications and treatment recommendations for headache care providers who serve children, adolescents, and families.
A literature search encompassed empirical published articles that were found by means of a search of MEDLINE and PsycLIT. Studies were chosen based on their relevance to the topic for this special edition. Due to the lack of scientific rigor employed in the majority of studies examining comorbidity and pediatric headache, it was not possible to develop specific inclusion criteria for studies included in this review, though we aimed to articulate the strengths and weaknesses of the studies reviewed.
DEPRESSION AND HEADACHE
Depressive disorders are reported to be a commonly encountered psychiatric diagnosis, with 6% to 8% of children and adolescents in the general population diagnosed with a depressive disorder.23 Many children and adolescents who suffer from chronic pain often present to physicians with physical complaints and symptoms of depression. In the adult literature, depression is reported to occur in 30% or more of headache patients (see Lake, Rains, Penzien, and Lipchik, 2005 for review). Correspondingly, both epidemiological and clinical studies of pediatric populations with recurrent headaches provide evidence to support an association between headache and depression.
Researchers have utilized the American Psychiatric Association (APA) diagnostic criteria from the DSM for assessing the prevalence of depressive disorders among the pediatric headache population. For example, Pine, Cohen, and Brook used DSM-III diagnostic criteria to demonstrate an association between headaches and depression in children, finding that headaches were twice as common in depressed adolescents than nondepressed adolescents. Seshia examined features associated with chronic daily headache (CDH) among a sample of 143 clinic-referred children and adolescents. Results of psychiatric evaluation indicated that 9% of the sample met DSM-IV diagnostic criteria for depression (base rates were not reported).24 Using a similar diagnostic technique, Kaiser examined the relationship between depression and headache among a sample of 30 headache patients aged 13 to 18 years seen for evaluation at a multidisciplinary clinic. Based on the clinic evaluation, which included a diagnostic interview derived from DSM-III-R criteria, 12 of 14 males and 12 of 14 females (86% of the entire sample) were diagnosed as having some manifestation of depression, either Dysthymia or Adjustment Disorder with Depressed Mood, based on patient reports of loss of interest and reduction in pleasurable activities as a result of chronic headache pain.25 It is not clear whether formal diagnostic assessment measures were followed in this study; however, licensed psychologists were reported to have made all diagnostic decisions, and so the diagnoses are reported to be reliable and valid. Anttila and colleagues found that in their population-based study of 12-year-old children with tension headache, 17% reported 2 or more depressive symptoms consistent with DSM-IV criteria, and Major Depression occurred in 1.5%.26 Guidetti and colleagues conducted an 8-year longitudinal study aimed at analyzing the evolution of headache and psychological comorbidity in 100 clinic-referred migraine patients aged 4 to 18 years. They reported that patients with migraine headache and tension-type headache reported clinically significant symptoms of depression on the Structured Clinical Interview for the DSM-III, and that comorbid symptoms of depression at baseline evaluation were related to worsening or enduring headache symptoms at 8-year follow-up.27
Researchers have also utilized dimensional assessment techniques to measure levels of depressive symptoms among headache patients. Reliable and valid pediatric-specific measures of depressive symptoms are available to assess the presence of depressive symptoms among children and adolescents. Research examining clinic-populations of children and adolescents and employing these measures have revealed elevated levels of depressive symptoms in headache patients as compared to non-headache controls.28–30 However, it is often found that although patients with headache report elevated symptom levels, both the headache and non-headache group means typically fall within the “normal range,” indicating that although the children with headache are considered to be statistically more depressed than children without headache, most are not clinically maladjusted.28 A population-based study of young adolescent Canadians responding to a national survey found that symptoms of depression were significantly associated with frequent headache (defined as headache occurring “about once a week or more frequently”), and that depression was a risk factor for the development of headache.31 In a follow-up study with the same national sample, Dooley et al reported similar findings.32 Specifically, they found that adolescents who reported feelings of unhappiness and sadness on a proxy measure of depression had an increased risk of headache, suggesting that symptoms of depression increase the risk of headache onset. Although these results are compelling, the authors neglected to use valid and reliable measure of depression, which significantly limits the findings.
Although the majority of available research findings from clinic and community studies support a relationship between symptoms of depression and recurring headaches, not all pediatric studies confirm these findings. Recently, Pakalnis and colleagues found that depressed mood was not significantly represented among their sample of school children with episodic migraine when compared to controls without a history of headache.14 In addition, Cunningham and colleagues found that for their sample of children with migraine headache, depression scores on a standardized measure were not significantly different from the depression scores of non-migraine controls.33 Another clinic study found that depression scores on the Children's Depression Inventory were not significantly different for migraine patients and non-migraine controls.34 Finally, Kaiser used the Beck Depression Inventory in conjunction with diagnostic criteria for additional understanding of the association between headaches and depression, and although 86% of the sample were diagnosed with a depressive disorder based on clinical interview, a substantial majority (63%) did not meet clinical cut-offs for Major Depression on this self-report depression questionnaire.25
The results of these studies en bloc demonstrate the lack of consistency in the current literature. Therefore, the nature of the relationship between psychopathology and headache remains unclear. Evidence was presented to support the notion of increased risk of headache in depressed individuals;27,31,32,35 however, it has been argued that it is unlikely that psychological illness causes headache.12 In fact, in the adult literature, evidence to contrast this hypothesis has been presented.36 Headache was also suggested to predispose children and adolescents to depression,28,33,37which has also been contrasted in the adult literature.38 Thus, it is not likely that depression results from the difficulty of living with recurrent headaches.12 The results of longitudinal studies suggest that the association between depression and headache may be bi-directional.19 The fact that several researchers have found no relationship between depressive symptoms and headache, further illustrates the complexity of the comorbid relationship between headache and depression.
Levels of self-reported stress and anxiety among clinical populations of children and adolescents with headaches have primarily been assessed through the use of validated, standardized dimensional measures developed for use with pediatric populations. Smith et al found that in their clinic sample of 276 adolescents (aged 11 to 18) with migraine, anxiety scores on a validated, standardized measure of anxiety were higher for migraine than non-migraine controls.39 Andrasik and colleagues found that adolescents with migraines reported more trait anxiety on a validated, standardized measure than matched controls without headaches.28 Similar findings for elevated trait anxiety scores for individuals with headache as compared to controls were reported by Larsson.40 It is important to note that these results should also be interpreted with caution, as the mean scores for the migraine group were not in the clinical range; so differences between groups indicated a relative difference in symptomatology and not the presence of a specific disorder. Mazzone and colleagues also reported that migraine and tension headache patients had higher anxiety scores on a validated, standardized measure than non-headache controls.30 Carlsson et al, in their sample of 113 school children aged 8 to 15 years, also found higher levels of anxiety on a questionnaire assessing family, school, leisure time, anxiety, worry, and restlessness reported by headache patients than matched controls.41
Few studies available utilized the APA's diagnostic criteria to assess anxiety disorders. One clinical study examined features associated with CDH among a sample of 143 clinic-referred children and adolescents. Results of psychiatric evaluation indicated that 6% of the sample met DSM-IV diagnostic criteria for an anxiety disorder (base rates were not reported).
Researchers have suggested that children with headaches may be more sensitive to everyday life stressors and daily hassles than children without headaches. Koch and Melchior explored associations with recurrent headaches in children.42 They reported, based on informal observations and interviews, that for the majority of children presenting to a headache clinic, stress and anxiety-producing situations precipitated migraine headaches and tension-type headaches. More recently, researchers have explored the hypothesis that children with recurrent headaches are more sensitive to stressors, using standardized assessment techniques. For example, in a study of children with migraine, aged 6 to 16 years, presenting to a pediatric clinic during a 4-month period, Cooper et al found that although all 39 of their subjects had anxiety levels in the normal range, those with higher self-rated anxiety scores on the Revised Children's Manifest Anxiety Scale at initial assessment reported more frequent and severe headaches at 4-month follow-up.43 They concluded that normal amounts of anxiety and stress lead to expression of migraine, but more anxious children with migraines have more frequent and severe migraines. Thus, although children with migraine do not experience more anxiety than their non-headache peers, they appear to be less able to cope with stress and anxiety, resulting in increased headaches. Kowal and Pritchard also noted that the results of their study of 9- to 12-year-olds with chronic headaches supported the concept that anxiety, perfectionism, and life stress contributed significantly to the prediction of the severity of headache pain.44 Finally, the results of one clinic study revealed that 42% of headache patients reported stressors that precipitated CDH.24 These findings suggest that anxiety and stress may initiate headache onset.
Although it may be concluded that there exists a relationship between anxiety and headache, there are studies available contrasting the association between anxiety and headache. For example, Pine and colleagues did not find an association between anxiety or mixed anxiety and depression and headache.35 Likewise, Pakalnis and colleagues reported that they did not find a significant difference in reported anxiety symptoms between children and adolescents with headache and non-headache controls.14
Despite the large body of evidence documenting an association between anxiety and headache, the exact nature of the relationship remains unclear. There are several potential explanations for the association between anxiety and headache. One explanation is that anxiety may cause headaches. As suggested by several studies, anxiety may be a precipitating factor that increases risk for headaches.24,30,40,41,44 Additionally, research suggests that some children may be less able to cope with daily life stressors resulting in an increased number, frequency, and severity of headaches.43 Conversely, headaches may trigger anxiety. In children with recurrent headaches, the level of anxiety has been reported to increase from childhood to adolescence,45 and researchers have found that a history of childhood headaches increases the risk for anxiety disorders in early adulthood.46 The results of longitudinal studies suggest that the association between anxiety and headache may be bi-directional. Although this relationship is not clear, there is evidence to suggest that anxiety influences headache, and one's response to stress/anxiety may increase headache frequency. Shared diathesis models have also been proposed.27,47 It is possible that anxiety shares a common diathesis with headache or represents a different aspect of headache. Egger et al reported that central nervous system serotonergic dysfunction may be a common point of neurotransmitter abnormality for depression, anxiety, aggression, and headaches.48 Finally, it is possible that associations found between headache and anxiety are an artifact of the study measures. Higher levels of anxiety reported by children and adolescents with frequent headaches could be a result of somatic items that are included on many anxiety questionnaires, which may mask headache symptoms and be interpreted as anxiety.
DEPRESSION AND ANXIETY AND HEADACHE
Researchers have suggested a relationship between depression, anxiety, and headaches. Mirikangas et al suggested that anxiety in childhood and adolescence preceeds migraine, and that a syndromic relationship between migraine, anxiety, and depression exists, such that anxiety in childhood precedes migraine and childhood migraine leads to development of depression.49 Guidetti and colleagues reported that their results also supported this theory, and that the absence of comorbidity among their non-headache patients, much more than the presence of psychiatric disorders among migraine patients, provided evidence for the presence of a syndromic relationship between headache, depression, and anxiety.27 In contrast to this theory, however, Egger and colleagues reported striking differences in outcomes for individuals with anxiety and depression.48 Specifically, they found that depressive girls reported more frequent headaches and more profound effects on their lives as a result of headaches than anxious girls. Thus, despite the seeming similar relationship with headaches, anxiety and depression were associated with distinct effects of headaches. The relationship between anxiety and depression and headaches by no means is fully understood. Indeed, in the general pediatric population, the diagnostic picture of depression and anxiety may be complicated by the high rate of comorbidity between the two disorders. Ongoing studies are sorely needed to evaluate fully the impact and course of these disorders and their association with headache.
PAIN/COPING, QUALITY OF LIFE, AND HEADACHE
The biopsychosocial model of headache (see Andrasik, Flor, and Turk, 2005) suggests that diversity in illness expression, including duration, severity, and consequences to the individual, can be accounted for by complex interrelationships among behavioral, affective, and cognitive influences.
Pain/Coping.— The elevations on measures of psychopathology observed among children with headache may be secondary to living with pain rather than being of etiological significance, and the experience of pain itself may serve as an important risk factor in the development of psychiatric disorders. Having pain can cause serious temporary or permanent impairment of everyday life functioning.50 Holroyd et al found that pain-state at the time of assessment mediated the levels of psychological symptoms among young adult headache patients.51 When pain levels were controlled, differences between headache patients and headache-free controls were no longer present. In contrast, Fichtel and Larsson found that in their population-based study of 793 adolescents, those with frequent headache but no ongoing pain at the time of assessment, reported more psychological symptoms than those with infrequent headache pain.52
Some researchers hypothesize that pain may lead to higher somatic focus and, therefore, may increase psychopathology; thus, the connection between headache and psychiatric symptoms may be related to a larger framework in which somatic symptoms and recurrent pain are related to psychiatric symptoms.53 Carlsson et al found that in their sample of school-going children with recurrent headaches, pediatric patients with headache evidenced more somatic symptoms and pain complaints than headache-free controls.41 In one population-based study of 1,135 children, somatic complaints were connected with headache,29 and in an associated study, children with migraine more often reported pains other than headache.54 However, as migraine is often accompanied by nausea, vomiting, visual and perceptual disturbances, dizziness and somatic complaints are in fact inclusion criteria for the diagnosis of migraine. As such, these results should be interpreted with caution.
The experience of pain has been associated with symptoms of depression and anxiety. In studies with adults, results have shown that depression and anxiety are related to sensitization of pain detection system and to the chronicity of tension headache.51,55,56 A positive association of headache, depression, and somatic symptoms has been reported in children with recurrent headaches.28,33 Specifically, Andrasik and colleagues found that in their sample of children experiencing recurrent migraine (aged 8 to 17 years), the headache group revealed greater somatic complaints than controls on several standardized measures, as well as increased symptoms of depression and anxiety.28 Kashikar-Zuck et al found that in their sample of 57 patients (mean age 14.81 ± 2.95 years) experiencing nonmalignant chronic pain, most patients showed mild to moderate levels of depression and 15% reported severe levels of depression.57
It has been suggested that anxiety influences the experience of pain by increasing the attention paid to the pain, which in turn increases anxiety. For children with chronic headaches, anxiety may increase because of repeated pain episodes and worry about future pain. Prior pain experiences influence pain evaluation and management, and more experience with pain does not necessarily portend more adaptive coping. In fact, negative pain experiences may sensitize an individual to more intense feelings of pain, may trigger memories of previous pain experiences, and may increase anxiety regarding how pain may impact their life, and increase worry about pain getting worse.58
Is there something special about headache pain that makes it a primary factor in the development of psychiatric disorders? Although chronic pain may be linked to increased psychiatric distress, it seems unlikely that depression or anxiety results only from recurrent headache and there is little empirical evidence to support that psychopathology results from headache pain specifically. In fact, headache and other recurrent pain syndromes have yielded similar results in terms of pathology. In one study, children with recurrent abdominal pain or headache were similar in symptoms of depression and anxiety.59 In another study, Cunningham and colleagues compared 20 boys and girls with migraine, matched for age and gender with a “pain” control group of 20 children with musculoskleletal pain, and with a “no pain” control group of 20 children.33 Both the migraine and pain groups had significantly more internalizing symptoms than the “no pain” controls. Notably, the migraine pain group and musculoskeletal pain group did not differ significantly from each other. The results from both these studies indicate that psychological symptoms and features thought to be characteristic of headache may actually be the result of having a chronic pain disorder. Therefore, characteristics such as “…anxiety, depression, poor social competence, social withdrawal, unhappiness, unpopularity, inattentiveness, and poor adaptive functioning” (p. 177) are most likely a result of the severity of a pain disorder rather than migraine headache.33
Although the relationship between pain and psychiatric symptoms does not appear to be limited to headache pain, there is research to suggest that frequent and severe pain, such as that experienced by children and adolescents with recurrent headache may lead to anticipatory anxiety, perceived loss of control, frustration, anger, or other risk factors for psychopathology. Recently, researchers have begun exploring the relationship between chronic pain and affective distress, suggesting co-sensitization of sensory and affective components of headache pain, resulting in an integrated relationship between headache and psychopathology in susceptible individuals.60 This certainly warrants future research and should be explored further, examining psychological symptoms in different groups of chronic pain patients, including headaches.
Quality of Life.— Health-related quality of life (QoL) is a multidimensional construct that reflects the impact of disease and treatment on a patient's subjective evaluation of his or her functioning and emotional well-being.61,62 The assessment of headache-related QoL in children and adolescents is an emerging area of research. Despite the paucity of research on the impact of headache on perceived QoL, the available studies provide compelling evidence that demonstrate the negative impact of headaches on children's QoL. Engstrom found in a sample of 20 headache patients aged 9 to 18 years, children experienced more somatic complaints, lower general well-being, were less communicative, and experienced more physiologic anxiety than matched non-headache controls.63 In another study of adolescents, participants with headaches reported worse psychological functioning, more physical symptoms, poorer functional status, and less satisfaction with life and health than headache-free controls.64 Powers and colleagues found that in their study of 572 patients between the ages of 5 and 18 years referred to a headache clinic, QoL was adversely affected in all areas of functioning when compared to healthy controls and the impact on QoL was similar to that of children with juvenile rheumatoid arthritis and cancer.62 In a population-based study of Swedish adolescents, Fichtel and Larsson found that adolescents with frequent headache had more functional disability when compared to those who had infrequent headache.52
As a result of unpredictable and severe headaches, emotional functioning may suffer as children experience repeated adjustment difficulties. Even in between headache attacks, the QoL of patients with recurrent headaches remains compromised.61 For example, children and adolescents may worry about whether a headache will start or worsen, fear that peers may not understand, worry about interference with social life and academic life, may feel fed up, loss of control, frustrated, angry, worried.65 The ability to perform everyday activities, such as going to school and participating in sports, are important areas for children and adolescents, and limitations in these areas can have significant negative psychological influences. In one study, depression was strongly associated with functional disability in children who experienced chronic pain.57 In another study of male adolescents, headache frequency, duration, and intensity were found to be associated with negative perceptions of QoL.66
The findings reported in these limited studies suggest that certain types of psychiatric symptoms may be a consequence of poorer QoL among these children and adolescents rather than antecedent conditions that cause headache, and psychopathology may exacerbate headache, particularly for children with poor QoL. This has potential to impact long-term functioning. Studies with adult patients with headache report that headache patients evidence worse mental health functioning, and physical, social, and role functioning.67
As noted in the previous sections, the methods used to assess psychiatric comorbidity and headaches vary substantially in the current literature. A key issue that emerges after examining this body of research is whether researchers are actually measuring psychopathology and whether different assessment techniques are measuring the same thing but at different levels of severity and specificity, and whether the various definitions and indicators of psychopathology are comparable. This is particularly important when considering the usefulness of results obtained from assessment and diagnostic techniques that are not standardized or recognized criteria for diagnosis of psychopathology. Despite results from numerous studies which reveal elevated levels of psychiatric symptoms observed among headache patients in comparison to controls, very few pediatric patients exhibit symptom levels that indicate the presence of a comorbid psychological condition, such as an anxiety disorder or depression.
Additionally, due to measures of psychopathology that to some extent reflect somatic or vegetative symptoms of chronic headache, it is possible that the findings from these studies overestimate the presence of psychological symptoms.12 Frequently, researchers overlook the potential impact of symptoms that are common to both psychopathology and headache (eg, reduced interest in activities, worry about physical symptoms/pains, poor appetite, difficulty sleeping). Consequently, elevations in depressive symptoms or anxiety symptoms may actually indicate the effects of headache-related, such as pain severity or decreased QoL, or shared symptoms of headache and psychopathology, but not necessarily a psychological disorder in isolation.
IMPLICATIONS FOR FUTURE RESEARCH
There is considerable uncertainty in the literature regarding the direction of the relationship between headache and psychiatric symptoms, and underlying biological or psychological causes linking headache and psychopathology. In light of more recent research, this view has been modified, and what appears to be most important to examine is the relationship between genetic, biochemical, emotional, cognitive, and behavioral factors and how they interact with one another to influence development of or occurrence of headache in children and adolescents. More research is needed to elucidate the nature and direction of these variables in relation to headache.
When conducting studies of comorbid psychological disorders and recurrent headache, standardized and recognized criteria (eg, ICHD-II, DSM-IV-TR) for the diagnosis of headache and psychological disorders is indispensable. Psychiatric diagnoses should be derived from formal diagnostic assessment methods and based on clearly specified diagnostic criteria. When dimensional assessment measures are employed to assist with diagnosis, clinically relevant cut-off scores should be identified and utilized for diagnosis. If symptom scores are elevated, but are at subclinical levels, scores should not be reported as “depression” or “anxiety.” In these cases, it may be more beneficial to discuss results from a symptom-level rather than a diagnostic-level. In addition, incorporating reliable and valid pediatric-specific measures of QoL and headache disability is vital for differentiating the impact of symptoms that are common to both psychopathology and headache (ie, transdiagnostic symptoms).
It would be valuable to utilize longitudinal research designs for future investigations of comorbid psychiatric illness and headache. Longitudinal research designs can address issues and support methods in ways that are not possible with cross-sectional approaches which have been used to-date. The statistical analysis techniques, such as path analysis, available to researchers employing longitudinal designs make longitudinal approaches ideal for determining which of two or more theoretically driven models most conform to underlying data. Longitudinal research designs are better suited for capturing temporal relationships among variables and can focus directly on change, which is useful for predicting long-term or cumulative effects which are typically hard to analyze in a cross-sectional study. In addition, longitudinal designs enable researchers to investigate causal relationships and processes which will promote understanding of the nature of the relationship between psychological symptoms and headache. Longitudinal studies may also increase our understanding of potentially important changes in headache experience and related psychological symptoms across developmental trajectories, providing further insight into the changing patterns of headache and comorbid psychopathology and help identify key points of intervention or effectiveness of treatment.
Certainly, there is evidence to suggest that a few pediatric headache patients exhibit symptoms indicative of a comorbid psychological condition. However, it is evident from the research presented in this review that a considerable number of children and adolescents who experience recurrent headaches do not evidence a diagnosable psychiatric condition. Many pediatric patients do report significant impairments in daily functioning, such as attending school and involvement in extracurricular activities, as a result of recurrent headache and symptom severity. Based upon the current body of evidence, a biospychosocial model of care may help integrate what we know to guide diagnosis, treatment planning, and measurement of outcomes.
Parallel to the recommendations for researchers, it is imperative that clinicians utilize appropriate, standardized, and valid criteria for the diagnosis of psychological disorders. A diagnostic approach to headache and psychological comorbidity must be incorporated into diagnostic evaluations. At the time of presentation to clinic, psychometric tests should be used to assist in diagnosis by assessing the level of psychological symptoms present. Patients who report clinically relevant levels of symptoms, as indicated by cut-off scores, should be further assessed using formal diagnostic assessment methods based on the DSM-IV diagnostic criteria to establish whether or not criteria is met for one or more specific disorders.
Treatment strategies should be based on the findings of the diagnostic evaluation and should address the antecedent and contributing factors. In a small, but not insignificant, percentage of patients, comorbid headache and psychiatric conditions will be diagnosed, which will likely effect adherence to prescribed treatment regimens. In these cases, referrals to appropriate persons may be warranted, in an effort to deliver evidence-based interventions that complement one another and promote adherence. For patients who report subclinical elevations on measures of psychopathology, the primary intervention regimen will be directed at reducing the symptoms of the headache disorder. Attention to potential barriers to adherence (such as psychological distress) is also needed in situations where the evaluation indicates elevations on psychological measures.
Measurement of outcomes for patients with comorbid presentations involves assessment of changes in key features of both the psychological symptoms and headache symptoms. Re-administering psychometric tests can be used throughout treatment to assist in outcome measurement by assessing the level of psychological symptoms present at each time interval. To assess improvement in headache symptoms, parameters of the headache experience (frequency, duration, severity) along with assessment of changes in QoL and disability is necessary. For patients who report subclinical elevations on measures of psychopathology, successful management of headaches should portend an improvement in psychological symptoms. If this does not happen, a re-assessment of ongoing concerns for the patient is indicated. Additional treatment may be necessary at this time to help the patient with ongoing concerns.
Although only a minority of pediatric headache patients exhibit psychiatric disorders, their presence generally portends a poorer outcome for headache management. When comorbid headache and psychiatric disorders are present for a patient, a comprehensive treatment approach is necessary. Active collaboration of pediatric specialists from multiple disciplines is indispensable for successful treatment of emotional functioning and headache symptoms.
The confusion surrounding the relationship between headache and psychopathology exists for several reasons. First, in some cases, headache has been inappropriately attributed to psychological or personality features based on anecdotal observations or interpretations which go beyond the available data. Additionally, measures of psychopathology have not always adhered to the APA's diagnostic criteria or utilized validated, standardized instruments, thus reducing the reliability, validity, and utility of diagnostic judgments.12,14 Furthermore, the diagnosis of headache has not always followed standard criteria, and has been complicated by the emergence of new terms, evolving measures, and potential adjustments needed in standard criteria to account for pediatric-specific aspects of headache.12,14 Finally, methodological shortcomings, such as incomplete descriptions of the procedures and criteria used for the study, inadequate descriptions of headache severity, lack of a control group for comparison with individuals without headaches, and the use of unstandardized assessment measures, have significantly limited the validity of research findings.
Comorbidity creates a need to study the content of risk and causal factors in a different way than studying pure headache diagnosis or pure psychological diagnosis. The complexity of these matters is quite challenging and ultimately creates a need for sophisticated research designs and methods. The fact that we can measure symptoms and apply diagnostic criteria has lead to greater study of this important topic, but at the same time, it might have misled us into believing that the relationships are more simple than they really are. Clearly, examination of headache and psychiatric comorbidity requires special considerations with respect to study design and methodology, analysis, and interpretation and reporting of results. Available data can help guide current practice in useful ways, but more rigorous research is necessary for advancements in evidence-based assessments and treatments of pediatric headache disorders.
Conflict of Interest: None