Anxiety, mood, and behavioral disorders among pediatric patients with juvenile fibromyalgia syndrome.

Juvenile primary fibromyalgia syndrome (JPFS) is a chronic pain condition characterized by symptoms of diffuse musculoskeletal pain and multiple painful tender points upon palpation. It is often accompanied by fatigue, poor sleep, chronic headaches, irritable bowel syndrome, and subjective soft tissue swelling.1 JPFS primarily affects adolescent girls and is typically recognized between the ages of 13 and 15. Siegel et al2 reported that JPFS is ranked as the 12th most common new-patient diagnosis representing about 7% of patients in pediatric rheumatology clinics. The long-term prognosis of children and adolescents with JPFS is unknown. Some community-based studies have shown that adolescents with JPFS may have a more favorable prognosis than adults.3,4 However, in clinical populations of adolescents with JPFS, 80% to 90% of patients continued to report pain, sleep disturbance, fatigue, stiffness, and other symptoms at 2 to 3 years of follow-up.2 Moreover, those with persistent JPFS symptoms tended to show more emotional problems,4 suggesting that a subgroup of adolescents with JPFS may have clinically significant psychologic symptoms that may affect their long-term functioning. The complexity of the presenting clinical picture in JPFS has not been sufficiently addressed in the literature. Similar to adult fibromyalgia syndrome (FMS), JPFS is often difficult to classify, because many of the symptoms are “medically unexplained” and often overlap with other medical conditions such as chronic fatigue syndrome, irritable bowel syndrome, and migraine headache. Comorbid psychiatric conditions, such as mood and anxiety disorders have been found to be prevalent in both clinical and community samples of adults with FMS.5–7 The estimated prevalence of concurrent mood disorders in adults with FMS ranges from 24% to 34%, with an estimated lifetime prevalence of 64% to 69%. The estimated prevalence of concurrent anxiety disorders in adults with FMS ranges from 15% to 32%, with lifetime prevalence of 35% to 47%.5,6,8,9 As might be expected, treatment-seeking FMS patients have greater psychiatric comorbidity than those who do not seek medical care.10 There is ongoing debate about the causes of psychiatric symptoms in FMS. That is, whether the symptoms are a consequence of living with chronic pain, or whether FMS and mood/anxiety disorders are an expression of the same disease spectrum, and share common familial risk factors. The current thinking supports a stress-vulnerability model of the pathogenesis of FMS in which FMS patients and their female relatives may share a common risk for heightened pain sensitivity and mood difficulties.11 When exposed to physical or emotional stressors, they are likely to experience increased pain and/or emotional symptoms. Regardless of the mechanisms, it has been found that adult FMS patients with greater psychiatric comorbidity tend to have poorer treatment outcomes than those with fewer psychiatric symptoms.12 Studying the presence of psychiatric disorders in children and adolescents with JPFS is a useful approach in providing greater insight on the issue of the development and course of symptoms over the lifespan of individuals with FMS. There is no documented evidence of the prevalence of specific psychologic disorders in children and adolescents with JPFS. The few studies, including our own, which have previously explored anxiety and depressive symptoms in JPFS have primarily relied on child and parent-report symptom checklists and found that psychologic distress was mildly elevated overall in adolescents with JPFS, similar to levels of distress in children with other chronic pain conditions such as juvenile idiopathic arthritis or chronic back pain,13,14 but a subgroup of JPFS patients seem to have severe mood symptoms.13 Although these studies point toward potential emotional difficulties in some patients with JPFS, it is not clear from elevations in scores on self-report questionnaires how many JPFS patients have symptoms severe enough to meet the criteria for psychiatric diagnosis. The primary objective of this study was to determine the presence of current and lifetime diagnoses of psychiatric conditions in a clinical sample of pediatric patients with JPFS using a standardized diagnostic interview for children: the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (K-SADS-PL15,16). Additionally, we gathered information about JPFS symptom severity (using physician global ratings and patient pain ratings) to explore the relationship between symptom severity and psychiatric status. It was hypothesized that the prevalence of mood and anxiety disorders would show a similar prevalence as adult samples of FMS patients, and that the presence of mood, anxiety, or behavioral disorders would be associated with greater JPFS symptom severity.