The movie Requiem for a Dream gives a graphic elucidation on drugs. They show you what would be the consequences of taking drugs knowingly and unknowingly.
The lead actors, Jered Leto and Jennifer Connelly are heroin addicts, they face challenges to keep up with the availability and the expense of the drug, Connelly is forced to do sell her body to get money to buy the drug.
There is another African American character who is falsely arrested because he was involved in a shootout (gang violence). Later on, he and Leto go to Miami to buy heroin because they had heard about a better deal, where they get arrested again because Leto's arm was falling apart. (The message here likely is, there is a possibility of a person getting arrested, and will have a negative impact on your well being when you are in the vicinity of drugs or have a link to it).
I understood the heroin side of the movie, they know it is bad for them and they still continue to do it because I think the drug has taken control over their reward system.
Now, Leto's mom Sara gets addicted to another drug unknowingly, which makes her fall into this loophole of losing weight and it's almost like OCD because she is constantly trying to appear pretty for this television show.
Was the television show a hallucination or was it real? What drugs did Sara take that got her addicted to the TV show? What was the message the film-maker was trying to convey with respect to Sara?