Case reports in this collection are detailed accounts of single patients or small clinical series, most of them describing people who detransitioned or whose requests for medical treatment changed. Their main contribution is depth: they document pathways, harms and clinical encounters that larger datasets rarely capture. The largest is a Finnish series of all nine adults who returned to a Helsinki gender clinic to detransition in 2018–2019; regret took seven years on average to appear, eight had undergone breast surgery, and mood disorders (89%), anxiety disorders (78%) and borderline personality disorder (56%) were common (Kettula et al., 2025). A UK series found 12 of 128 adolescents (9.4%) stopped seeking medical treatment during extended assessment, most of them girls and seven with an autism diagnosis (Churcher Clarke & Spiliadis, 2019). Single cases describe harms not usually measured, such as grief at being unable to breastfeed after mastectomy at 20, with no recalled pre-surgical discussion of it (Gribble et al., 2023), or testosterone prescribed at 18 after a 30-minute appointment, followed by two psychiatric hospitalizations (Marchiano, 2021).

A recurring theme is that gender distress came to be understood, in hindsight or in therapy, alongside trauma, grief, family conflict or difficulty growing up female (D'Angelo, 2020; D'Angelo, 2025; Kettula et al., 2025). These reports have also prompted practical recommendations, including breastfeeding counseling before mastectomy and easier routes for detransitioners to return to clinics.

Limits of the evidence

The method cannot establish how common any of these experiences are, nor what caused them. Samples are tiny, there are no comparison groups, and percentages in the Finnish series rest on counts below ten, with some figures in its discussion not matching its own tables. Accounts are often reconstructed after regret, from memory or clinical notes, and interpreted by the treating clinician without validated measures or independent review. Details are frequently altered for anonymity, and several authors hold stated positions on gender medicine. Case reports are best read as hypothesis-generating signals that point to questions for larger, prospective studies.