Project Summary Migraine is a highly prevalent and disabling disorder that affects 15% of children and adolescents worldwide. Adolescents with migraine frequently undergo changes in their disease symptoms during puberty, with individuals experiencing increases, decreases, or no change in headache frequency. It is not currently possible to predict if an individual will experience improvement, no change, or worsening of migraine symptoms, and the underlying mechanisms controlling these changes remain uncharacterized. Thus, in the proposed study, we aim to identify the baseline factors determining migraine prognoses in adolescents (Aim 1), determine the hormonal, neural, and psychophysical changes related to migraine prognoses in adolescents (Aim 2a), and identify the temporal relationships between hormonal, neural, and psychophysical changes preceding vs. following changes in headache frequency (Aim 2b). Preliminary data support testosterone levels, conditioned pain modulation (CPM) response, and functional connectivity (FC) of the amygdala as factors that may determine migraine prognosis. Our preliminary data indicate that CPM response and amygdalar FC at baseline may predict the change in headache frequency following a behavioral intervention in adolescents with migraine. In addition, changes in testosterone levels are associated with changes in migraine symptoms. Study participants will be adolescents with episodic migraine (ages 10–13, 50% females, migraine onset > 6 months, headache frequency between 4–15/month, without or with a stable preventative treatment for migraine). Psychophysical, neural, and hormonal factors will be assessed at baseline and at 1- and 2-year follow-ups. Participants will meet with a headache specialist at all study visits to confirm migraine diagnosis and for rigorous characterization of migraine symptoms. Migraine outcomes will be categorized as an increase or decrease (> 30%) or no change (< 30%) in headache frequency from baseline to 2-year follow-up. A healthy control group will complete all study procedures to control for normal pubertal changes. We hypothesize that male sex and greater CPM responses, lower amygdala-prefrontal cortex (PFC) FC, and higher testosterone levels at baseline will be associated with a decrease in headache frequency after two years. We expect that adolescents with increased headache frequency will have a greater reduction in CPM efficiency, increased amygdala-PFC FC, and a smaller increase in testosterone levels compared to adolescents with a decrease or no change in headache frequency and healthy adolescents. We expect smaller increases in testosterone levels to precede increases in headache frequency and greater reductions in CPM efficiency and increases in amygdala-PFC FC to follow increases in headache frequency. Characterizing the mechanisms underlying changes in migraine symptoms is imperative for the development of new migraine treatments. Identification of adolescents who are at...