I don't believe he had a drug problem. I think the media is speculating on things they really don't understand. All the medications found in his apartment were legally prescribed to him.
NYPD sources tell TMZ that nearly full pill bottles containing the anti-anxiety medications Alprazolam (Xanax), Diazepam (Valium) and Lorazepam (Ativan) were found in the apartment. The sleeping medication Zopiclone (Lunesta) and the sedative Temazepam (Restoril) -- which is used by people with "debilitating insomnia" -- were also found.
I think sometimes we forget that celebrities are people too and have their own mental health issues. Take for example the last year's events in Ledger's life. His girlfriend, who he loves more than life itself, dumps him and takes their baby girl with her. While they were still in contact, he was devastated. He probably felt like his world was falling apart. But in no way am I insinuating Ledger took his own life. I think, like a responsible person, he sought help from a medical professional to get his life back on track and not feel utterly empty and depressed over this turn of events. I'm guessing that he was in therapy and was prescribed the medications to help him begin feeling better.
It's sad that the media is making all these claims when I think this story is just an utter tragedy. A life was taken much too soon and Matilda will now grow up fatherless. I think it's important to respect the privacy of the family and not continue to speculate on the events that led up to Ledger's tragic death.