The broad aim of the study is to implement and evaluate the efficacy of Graded Exposure Treatment (GET Living) to target elevated pain-related fears in children with chronic pain. Pain-related fear is an important psychological factor associated with poor outcomes in children suffering with chronic pain. To examine the efficacy of GET Living in addressing pain-related fears the investigators propose to use a sequential replicated randomized single-case experimental phase design with multiple measures. The specific aims are to 1) evaluate the effectiveness and acceptability of individually tailored GET Living for children with high pain-related fear and functional disability and 2) define anatomical and resting state connectivity patterns in the brains of children and adolescents with complex chronic pain prior to and after participation in GET Living.

Inclusion Criteria:

• Pain-related fear (score >40 on the Fear of Pain Questionnaire (FOPQ (Simons et al., 2011a))
• Musculoskeletal, neuropathic limb or back pain, or headache
• Functional limitations (score > 12 on the Functional Disability Inventory (FDI (Kashikar-Zuck et al., 2001; Walker and Greene, 1991)).

Exclusion Criteria:

• Significant cognitive impairment (e.g., intellectual disability)
• Serious psychopathology (e.g., active suicidality).
• Acute trauma (e.g., spondylolithesis, disk herniation, fracture, acute tendonitis)
• Systemic disease in active inflammatory state
• Biomechanical deficit that would limit ability to engage in exposure activities (e.g. severe muscle atrophy)
• Making gains in current physical therapy or have not had physical therapy, but it is clearly indicated