Princess Diana, the late Princess of Wales, may have shown signs of attention-deficit hyperactivity disorder (ADHD) as a child, according to her brother Charles Spencer's upcoming memoir, Swan Song: Diana, My Sister. The book, set for release on 22 September 2026, details how Diana's teachers frequently noted her challenges with focus and restlessness. At the time, ADHD was not widely recognized or understood in England, and Diana was never officially tested for the condition. Diana's kindergarten teacher observed that she had a short attention span and struggled particularly with lessons that required passive learning, such as listening rather than participating actively. When she became bored, she would often stand up from her desk and interject, finishing other students' sentences. At Riddlesworth Hall, where she began prep school at age nine, a report noted that she had difficulty concentrating and became restless during lessons. Teachers described her as easily distracted and quick to give up on difficult tasks, often retreating into her own world instead of facing challenges. In an interview with the BBC ahead of the book's release, Charles Spencer revealed that he and Diana both likely have ADHD. While Diana was never formally diagnosed, Spencer said he has come to recognize that he experiences Rejection Sensitive Dysphoria (RSD), a term used to describe an intense emotional reaction to perceived rejection or criticism. RSD is often linked with ADHD but is not considered a formal medical diagnosis or an official symptom of ADHD, according to the Cleveland Clinic. Spencer also wrote about how Diana, at times, contemplated ending her life, but her love for her sons stopped her from acting on these thoughts. Diana's youngest son, Harry, has spoken about attention difficulties, though he has not publicly confirmed an ADHD diagnosis. During a 2023 live-streamed conversation with physician and author Gabor Maté, Maté suggested that Harry might have attention deficit disorder after reading his book Spare and speaking with him. Maté noted that such conditions can be "healed at any age," to which Harry humorously responded, "Thanks for the free session." Maté later clarified that he was not diagnosing Harry with a medical condition, but rather identifying a response to challenging life circumstances.