I think we underestimate our young people. Tell them the pros and cons. Informed adolescents quickly grow into educated adults. And there are cons, a young persons emotional development can be halted if they numb those emotions with any substance thc, etoh or prescribed antidepressants or anxiolytic.
Family history of psychosis means you may be more susceptible to paranoid ideas. It does complicate issues for schizophrenic people. Depressed people may become less motivated and melancholic.
Equally if you give an adolescent antidepressants (and many do whether you agree or not) and you increase their suicidal risk dramatically in those first few weeks.
Along with many other Side effects too.
Information is key. Open dialogue with young people with respect for their intellect and growing independence. Why feed a 15 yr old scare tactics and propaganda.