Puberty blockers aren't OTC, they're prescribed by doctors. The kid's not making the judgement so much as they're bringing up the medical issue to a professional.

I was diagnosed with depression at a fairly young age, just entering into my teens, but I only got in to see a psych to begin with because I was worried enough to self-advocate. Can't really imagine what it would be like if I was told that I was too young to understand depression and turned out on my metaphorical ass.