• Severity of pain from the 100-mm visual analog scale of the Pediatric Pain Questionnaire [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  

• The Mean Tender Point Pain Threshold will be assessed for all 18 tender points. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  
• The Clinical Global Impression of Severity scale evaluates the severity of illness at the time of assessment. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  
• The Patient Global Impression of Improvement measures the degree of improvement since randomization at the time of the assessment. [ Time Frame: since randomization at the time of the assessment ] [ Designated as safety issue: No ]
  
• The Functional Disability Inventory-child version assesses perceived difficulty in performing activities in the domains of school, home, recreation, and social interactions. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  
• The Functional Disability Inventory-parent version consists of the same 15 items as the child version but allows the parent to provide their perception of the child's difficulty in performing activities in physical and psychosocial domains. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  
• Children's Depression Inventory is a self-reported scale that is widely used in studies of children with fibromyalgia. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  
• Multidimensional Anxiety Scale for Children is a self-report inventory that assesses four areas of anxiety symptoms. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  
• Fibromyalgia Impact Questionnaire Modified for Children is a self-report instrument that measures function, pain, fatigue, sleep quality, stiffness, anxiety and depression. [ Time Frame: at the time of the assessment ] [ Designated as safety issue: No ]
  

Drug: Fluoxetine
fluoxetine po 10-60 mg/day for 12 weeks

Fibromyalgia is a common condition that is often challenging to treat. It is defined by the American College of Rheumatology (ACR) as widespread pain of at least 3 months duration in combination with tenderness at 11 or more of 18 specific tender point sites on the body. The prevalence of JPFS in children and adolescents in the general population of the United States is unknown. Studies from Israel, Mexico, and Italy have estimated that the prevalence rate of JPFS in school children ranges from 1.24% to 6.20%, with girls making up the majority of cases. Information from a national registry in the United States indicates that JPFS accounts for about 7.7% of new patient diagnoses in a pediatric rheumatology setting. The mean age of onset of pediatric JPFS is 12 years. As in adults, JPFS has been diagnosed in children and adolescents using the ACR criteria. JPFS often leads to substantial morbidity and disability. For example, adolescents with JPFS reported significantly greater functional disability and greater number of school absences than those with other rheumatic diseases such as juvenile RA or lupus. The presence of high levels of pain and disability at this critical developmental stage place adolescents with JPFS at greater risk for long term social and occupational difficulties. Early diagnosis and effective intervention are therefore of critical importance.

Inclusion Criteria:

• Female or male outpatients 13 to 18 years of age.
• Fulfillment of the American College of Rheumatology (ACR) criteria for primary fibromyalgia.
• Ability to understand and cooperate with study procedures.
• Provision of parental written informed consent and verbal and written assent from the adolescent for participation in the study.

Exclusion Criteria:

• Unwillingness or inability on the part of the parent to provide written informed consent or for the adolescent to provide verbal and written assent.
• Lifetime history of psychosis, hypomania or mania.
• Diagnosis of alcohol or substance abuse or dependence within 6 months prior to screening visit.
• Patients judged to be at serious suicide or homicide risk.
• Girls who are pregnant or lactating. Girls of childbearing potential who are not using a medically accepted method of contraception (including barrier or hormonal methods).
• Clinically unstable medical or psychiatric conditions that could interfere with the absorption, metabolism, excretion, or safety of fluoxetine or interfere with the assessment of disease severity.
• Inability to exclude traumatic injury, regional or structural rheumatic disease, or infectious arthropathy as the etiology of their relevant fibromyalgia symptoms and that would interfere with interpretation of outcome measures (e.g., osteoarthritis, bursitis, tendonitis).
• History of an autoimmune disease or inflammatory arthritis, such as systemic lupus erythematosis (SLE) or rheumatoid arthritis (RA).
• Treatment with a monoamine oxidase inhibitor, tricyclic, SSRI antidepressant, or lithium within 2 weeks prior to beginning study medication.
• Treatment with analgesic medication (with the exception of acetaminophen and over-the-counter NSAIDs) within one week prior to beginning study medication.
• Treatment with any other excluded medication that cannot be discontinued at the screening visit.
• Previous treatment with fluoxetine.
• Treatment with any investigational medications within 30 days prior to screening.