Ben Mathis-Lilley isn't concerned about the career of Miley Cyrus following a leaked video of her copping to her weed habit:
For one, hard drugs aren’t something "accessible" celebrities do. "I bet if we met we would really get along, just talking and smoking meth and getting arrested" is not a thing people think about their favorite singer or actor. Furthermore, even for those with very flexible professional schedules, uppers have a problematic tendency to totally incapacitate—see the wasted years of talents like Lohan and Robert Downey Jr.
By contrast, if you’re an artist who has employees to schedule appointments and pay bills, the typical drawbacks of weed-smoking (slovenliness, excessive listening to Otis Redding) can be made irrelevant or even useful. If Jack Nicholson, Tom Petty, and Brad Pitt are any indication, it seems possible to have a long, consistently productive marijuana-fueled career.
But if you aren't rich and famous, you're screwed of course, especially if you're black or Latino.