Some drugs are prohibited in some jurisdictions, though the details vary between jurisdictions. Illegal drugs generally are somewhat of a taboo subject, and discussions surrounding them should be handled sensitively. The N in PARSNIP covers such drugs (as narcotics).
Drug education is a whole approach to teaching people about drugs. This should ideally be evidence-based, but conservatives typically reject evidence that doesn't fit in with their preconceived ideas and instead insist on signalling their own virtue to their supporters, to the detriment of people's health.