The goal of this interventional study is to assess the efficacy of a therapeutic intervention aimed at diminishing pediatric chronic headache. This intervention is based on the development of relaxation skills, particularly the practice of deep breathing, using virtual reality in conjunction with a biofeedback device. Specifically, it aims to assess the relevance of this tool both in learning relaxation techniques and in changing cognitions involved in pain adjustment, such as self-efficacy and pain catastrophizing. The main hypothesis is that the intervention using virtual reality will lead to greater daily use of the relaxation techniques learned, as well as an increase in the associated self-efficacy, resulting in a reduction in headaches (in terms of frequency and intensity) both immediately after the intervention and two months later. A secondary hypothesis is that this intervention will contribute to a decrease in negative pain perceptions, pain catastrophizing, and functional disability. A tertiary hypothesis is that the intervention will lead to an improvement in the child's quality of life. The effects of this intervention will be compared to those of a similar intervention without the use of virtual reality, as well as to a control condition in which only psychoeducation is provided.