Is Paula Abdul's dishevelled behavior due to pain killers for her chronic pain or from drugs or alcohol?

I was watching interviews with her from years ago and she seems like a complete different person now. In some of her recent appearances she has slurred words, couldn't keep balance while sitting, and generally appeared to be under influence of some sort of drug. I've heard that she suffers from chronic pain due to an injured back, but many people take meds for pain and don't end up so dishevelled. Do you think she has a drinking or a drug problem? I have nothing against her as a person, she actually seems like one of the nicer celebrities out there, but I'm just curious why she is so different now as opposed to just several years ago.