Conversation so far:
Paul McCartney do drugs?
McCartney first used drugs in the Beatles' Hamburg days when they often used Preludin to maintain their energy while performing for long periods.
What kind of drugs did Paul McCartney take?
marijuana and cocaine
Did Paul McCartney have an addiction problem?
Use of the drug soon became habitual, and according to Miles, McCartney wrote the lyrics another kind of mind in Got to Get You into My Life specifically referencing cannabis.
Did Paul McCartney seek help for addiction?

Question: How did the drugs effect his preformance?
Self-contained rewrite: How did the drugs effect Paul McCartney's performance?