法的な性別変更を元に戻したのは、スウェーデン人2,467人中わずか21人――ただし法的な取り消しはデトランジションのごく一部しか捉えない

性別違和のある成人における法的性別変更後の安定性

Authors: Kristen D. Clark, Richard A. White, Georgios Karamanis, Malin Indremo, Fatih Özel, Alkistis Skalkidou, Thomas Frisell, Fotios C. Papadopoulos
Journal: JAMA Network Open
Year: 2025
Source: https://doi.org/10.1001/jamanetworkopen.2025.27780

Summary

Researchers in Uppsala used Swedish national records to follow everyone first diagnosed with gender dysphoria between 2013 and 2023, 7,293 people. They checked who changed legal gender and who changed back. About a third (2,467) made a legal change. Only 21 changed back, so the estimated chance of keeping the new legal gender for 10 years was about 98%. The records are complete, but narrow. In Sweden, changing back needs a new application and a psychological assessment, so it is only a small, formal part of detransition. People who stop hormones, regret surgery or re-identify with their birth sex without changing their papers are not counted. Most people were followed for only a few years after their legal change, while detransition often happens 5 to 10 years after transition. The study shows that changing legal gender back is rare; it does not show that detransition is rare.

Key findings

この研究は、2013年から2023年の間にスウェーデンで初めて性別違和と診断された7,293人全員（女性として生まれた4,083人、男性として生まれた3,210人）を対象とし、それぞれ平均約5年間追跡されました。
2,467人（34%）が、平均して最初の診断から3.2年後に法的な性別を変更しました。10年以内に変更する確率は推定58%でした。
法的な性別を生まれつきの性別に戻したのは21人だけで、変更した人の0.9%、全体の0.3%でした。
新しい法的な性別を10年間維持する確率は推定約98%（おそらく96%から99%の間）で、女性として生まれた人と男性として生まれた人の間に違いはありませんでした。
元に戻した21人は他の人と似ており、18歳より前に診断されていたのは2人だけで、元に戻したときの平均年齢は約30歳でした。
著者らは、法的な性別を元に戻すことはデトランジションと同じではなく、理由や自認については何も語っておらず、最小限の数字として扱うべきだと強調しています。
論文の考察では、元に戻す割合を法的な変更をした人の0.09%としており、これは論文自体の結果の0.9%（2,467人中21人）より10倍低い値です。

Abstract

IMPORTANCE: The number of people seeking treatment for gender dysphoria (GD) has risen in recent decades, yet data remain limited for understanding cases of detransition (ie, the reversal of social, medical, or legal transition). Legal gender change in national registers poses an opportunity to examine legal gender reversals, which may reflect an aspect of the detransition process, while also informing an understanding of the stability after a legal gender change. OBJECTIVE: To determine the probability of obtaining a legal gender change and its stability over time among people diagnosed with GD in Sweden during a 10-year study period. DESIGN, SETTING, AND PARTICIPANTS: In this population cohort study using data from Swedish national registers from January 1, 2013, to December 31, 2023, individuals who received their first International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10), diagnosis code for GD during the study period were included. While participants may have received a GD ICD-10 code as youths, legal gender changes only occurred for adults (aged ≥18 years) based on legal requirements during the time of data collection. EXPOSURE: Gender dysphoria. MAIN OUTCOMES AND MEASURES: Legal gender change and its stability, that is, absence of legal gender reversal, as reported in the registry. Kaplan-Meier survival analysis was used to determine the probability of legal gender change and its stability during a 10-year study period. RESULTS: A total of 7293 people with a GD diagnosis were included (36 025 person-years). Approximately one-third of the sample (n = 2467) obtained a legal gender change during the study period. The probability of legal gender change at 10 years following diagnosis was 58.3% (95% CI, 56.2%-60.4%). Twenty-one cases of legal gender reversal were identified. The probability of legal gender stability at 10 years following the initial change was 97.7% (95% CI, 96.3%-99.2%), with no differences by sex assigned at birth for either outcome. CONCLUSIONS AND RELEVANCE: In this cohort study using national population registry data, a significant proportion of participants with GD in Sweden obtained legal gender change within 10 years of follow-up. Despite significant growth of the population with GD, the probability of legal gender stability during the 10-year study period was high, at almost 98%. These results highlight that legal gender reversal was an infrequent occurrence in a national sample.

Conclusion

In this cohort study using national population registry data, a significant proportion of participants with gender dysphoria in Sweden obtained legal gender change within 10 years of follow-up. Despite significant growth of the population with gender dysphoria, the probability of legal gender stability during the 10-year study period was high, at almost 98%, and legal gender reversal was an infrequent occurrence in a national sample. No differences by sex assigned at birth were observed, and most individuals who legally reverted were in their twenties at first diagnosis. The authors note that legal gender reversal is not synonymous with detransition, should be considered a lower-bound approximation, and cannot be generalized to social or medical detransition.

Methodological limitations

Only a narrow sign of detransition: The study only counts formal changes in the national register. It misses people who stop or reverse hormones, regret surgery, or re-identify with their sex without changing documents. The authors call it a minimum estimate that cannot be applied to social or medical detransition.
Changing back is hard: In Sweden, changing legal gender back needs a new application and a psychological assessment, which puts people off. Detransitioners may also have practical reasons to keep their new legal gender, such as matching a passport to a body changed by surgery or avoiding explaining themselves again and again.
Follow-up too short: People were followed for about 5 years from diagnosis on average, and the legal change came about 3 years after diagnosis, so most were watched for only a few years afterwards. Studies the authors themselves cite put the gap between transition and detransition at about 5 to 8.5 years.
The 10-year figure is shaky: Few people were followed for the full 10 years, and the authors themselves urge caution. The 98% figure is a projection based mainly on the early years.
The paper contradicts itself: The results report 21 reversals among 2,467 people (0.9%), but the discussion says 0.09%, ten times lower. Comparisons with other detransition estimates (2% to 16%) are therefore misleading as written.
Only the most committed could be counted: Only people who finished Sweden's slow process (diagnosis, treatment, and age 18 or over) could change legal gender. These are the most committed and most thoroughly assessed patients, so the results do not apply to everyone diagnosed, or to young people.
Gaps in the records: People entered the study when a diagnosis code appeared in hospital records, which captured only about 81% of outpatient visits in 2013. The code marks the first recorded visit, not when gender distress began or when social transition happened.
Nothing on reasons or wellbeing: Records cannot show why people changed back or whether those who did not are doing well. "Stable" here only means no paperwork change, not satisfaction or lack of regret.
Only male or female options: Sweden has no non-binary legal gender, so people who moved toward a non-binary identity could not show up as changing back.
Conflicts of interest: One author (Karamanis) said he volunteers for Transgender Europe, a trans advocacy group. University press releases said the results showed "very few regret", which goes beyond what the study measured.

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Summary

Key findings

Abstract

Conclusion