Biggs notes that both studies lack controls, and we cannot be attribute changes to the treatment effect. Vries et al. also combines pubertal suppression with psychological support, meaning that changes may be the result of this support.
In the Dutch study males and females improved on several psychological function measures. However, female psychological functioning deteriorated in the English study. Notably, this deterioration included increased suicidal behaviour (emphasis added):
...after treatment, female subjects were more likely to state that they sometimes “deliberately try to hurt or kill myself” ... (Affirmative answers also increased for the other question on self-harm—“think about killing myself”—but this was not statistically significant.)
In both the Dutch and English studies, female adolescents became more dissatisfied with their bodies. Biggs concludes (emphasis added):
The comparison with the Early Intervention Study reiterates a neglected aspect of the original Dutch findings: female adolescents treated with GnRHa became more dissatisfied with their bodies. This fact might help to explain why this treatment almost invariably leads to further physical interventions. At the Leiden gender clinic, 96% of adolescents treated with GnRHa continued to cross-sex hormones, and only 4% discontinued...Although puberty suppression is still described as an “extended diagnostic phase”...in practice, it becomes the first stage of irreversible physical transition.
The two studies draw from the two cohorts examining the psychological effects of puberty blockers in the published literature. Both have several limitations and mixed results. Based on the above analysis, NZ clinicians must inform parents of children considering puberty blockers that:
- There is no firm evidence of a psychological improvement effect from puberty blockers.
- There is a risk of increased suicidal behaviour and body dissatisfaction, particularly in female adolescents.
- Following treatment, the child may wish to continue to cross-sex hormones, but this desire may follow from a dissatisfaction effect of the puberty-blocking treatment.