Princess Diana's brother suggested his sister may have had undiagnosed ADHD

On September 22, 2026, the memoir by Charles Spencer, brother of the late Princess Diana, titled "Swan Song: Diana, My Sister" was published. In it, the Earl Spencer shares memories of his sister's childhood, her life in the royal family, and her final years. One of the most discussed topics in the book is the author's suggestion that Diana may have had undiagnosed attention deficit hyperactivity disorder (ADHD).

Personal experience as a key to understanding his sister

Charles Spencer himself received an ADHD diagnosis in adulthood. In his words, this changed his perspective on the difficulties Diana faced in childhood. He notes that his sister had problems with her studies: she struggled to concentrate, had difficulties with spelling and word and letter order. Spencer also suggests that Diana may have had dyslexia.

Corroboration from school reports

The brother's observations partially align with the characteristics he says are quoted from school reports in the memoir. Teachers noted from an early age that the girl found it hard to focus for long, could become restless in class, and was easily distracted. One report indicated that poor concentration was hindering her learning. In Spencer's view, these details fit the profile typical of ADHD.

"Rejection sensitivity" and emotional reactions

The author separately addresses his sister's emotional reactions to conflicts with close people: Diana could cut off contact with someone for a long time if she felt let down by them. Spencer links this to what he calls rejection sensitivity and mentions the term "rejection sensitive dysphoria" (RSD). It is important to note, however, that RSD is not a separate official medical diagnosis or a formally recognized symptom of ADHD.

Contradictory reporting

Reporting in various outlets differs in its wording: some headlines present the information as an established fact ("suffered from ADHD"), while Spencer himself consistently speaks only of his own speculation and explicitly states that he does not want to diagnose his sister retrospectively. Thus, the memoir is not evidence that Diana had ADHD: it is the author's personal interpretation, based on his own experience and memories, rather than a medical conclusion. The difference between "may have had" and "suffered from" matters for a correct understanding of the material.

The author's purpose

According to Charles Spencer, his goal is not retrospective diagnosis, but explaining his sister's behavioral traits through his own experience and showing how difficult the period was for Diana, when much less was known about such conditions. The book thus functions more as a personal testimony and an attempt to reframe her biography than as clinical material.