Hormone Therapy & Suicidality: What The 2025 Follow-Up Study Shows.
In 2019, coming out of my dissertation (Allen et al., 2019), my co-authors and I published a small observational study (N = 47) examining changes in well-being and suicidality among transgender and non-binary (TNB) adolescents after the initiation of hormone therapy (HT). Given the replication crisis in the sciences (Ioannidis, 2005; Open Science Collaboration, 2015) and the well-documented decline effect (i.e., where initially large effects often shrink or vanish with replication; see also my Blog on Purple Hat Therapies)—larger, better-designed replications are necessary before drawing strong conclusions.
This year, we completed a substantially expanded follow-up with more than 400 youth, allowing us to revisit our earlier findings with a larger cohort and over a longer observation window. Although many studies in gender care, especially around youth, remain constrained by the practical and logistical limits of ethical clinical research (small samples, short follow-up periods, and the difficulties of conducting randomized controlled trials) accumulating evidence strengthens our confidence when patterns recur across independent datasets.
Our 2025 study, Changes in Suicidality Among Transgender Adolescents Following HT: An Extended Study, confirms the primary findings of the initial 2019 research. The reduction in suicidality following HT remains significant. The estimated effect size decreased from large to medium, which is expected with a larger sample (aligning with broader trends in replication research).
The most salient pattern in the expanded sample (N = 432) was a reduction in self-reported suicidality among TNB youth:
| Outcome Metric | Baseline (Start) | Follow-up (End) |
|---|---|---|
| Endorsing Suicidality | 92 (21.3%) | 32 (7.4%) |
| Reported Recent Suicide Attempts | 13 (3.0%) | 2 (0.5%) |
First, its important to highlight that most TNB youth did not report suicidality at baseline, and many are flourishing in school, relationships, and daily life. Among those who did endorse suicidality at baseline, the rate dropped by nearly two-thirds (65.2%) at follow-up, and the number reporting recent suicide attempts declined by 84.6%. Although observational studies cannot definitively establish causation, seeing similar improvements across multiple samples makes it increasingly likely that the association reflects a real trend worth taking seriously. In fact, no reasonable analytical decision could obscure the finding that suicidality significantly decreased (Allen et al., 2025b).
This follow-up study matters because evidence in medicine accumulates over time. It would be rare that one study settles any question (though, I am in favor of devoting resources to larger, better studies rather than multiple small studies). Evaluating evidence requires assessing the limitations and quality of individual studies, as well as replication and convergence across methods and populations. Science is inherently iterative and self-correcting (Nosek, 2025). Even studies with acknowledged limitations can still contribute when their results align with broader empirical patterns.
In the area of gender care for TNB youth, the pattern of findings have been notably consistent. Across dozens of studies, transgender youth who begin HT typically experience measurable improvements in a wide range of outcomes (Turban, 2025; Budge et al., 2025). Of course, evidence is not perfect or without limitations, and causal inferences should be made cautiously. Some improvements may also reflect maturation, psychosocial support, expectations of benefit, or broader changes in life circumstances. And some of these positive changes may have only been enabled by HT. Still, the recurring pattern across independent studies suggests that the observed improvements are unlikely to be purely random or idiosyncratic.
But evidence-based medicine has never been only about the data. The evidence alone cannot tell us or a patient what to do. Clinical decisions require incorporating patients and stakeholders’ values and preferences. Different people place different weights on potential benefits and risks, and evidence alone cannot settle some of those value judgments and levels of risk tolerance. Of course, choosing not to do something also is not value neutral or risk free.
As a mental health practitioner, clarity about the role and limits of therapy is important. There are things therapy can and cannot do. There is no credible evidence that therapy can reliably change a person’s gender identity or reduce gender dysphoria by attempting to alter it directly. The aim of (gender) therapy lies elsewhere: to help patients understand themselves, explore their self-expression and what feels right for them, clarify their values, and make informed, values-aligned decisions. This includes supporting patients whether they pursue medical interventions or decide that non-medical approaches or non-treatment are right choice for them.
If we are practicing good gender care, we are never telling any patient “You are transgender and you need X intervention.” It is about supporting the patient as they figure that out themselves (if they don’t already know) and providing accurate information about the full range of treatment options, which may include non-treatment, and ensuring that any decision is grounded in informed consent.
Stepping back, the picture we see across the literature is one of consistent evidence of benefit, albeit based on studies that vary in design and often face significant methodological constraints. The ‘signal’ is not perfect and does not meet strict causal standards (most medical interventions do not). But the findings regarding gender care for youth are stable across time, samples, and research groups, and reflect the best evidence we currently have in a challenging and evolving field of study. That is what science looks like in the complexity of real life. And ultimately, decisions about care must be made collaboratively by families and knowledgeable clinicians who understand the developmental context, the values and preferences of those involved, the limitations of current evidence, and who adhere to established standards of care.
