methadone treatment

I work with a person who goes to a clinic for methadone treatments daily sometimes, and then other times she is given three treatments to give herself per day.  It really dosen't make any sense to me, because sometimes she is on the ball and other times she is nodding off, slurring in her speach, and not present intellectually.  Why is this and why if she stopped treatment for 5-6 weeks a couple of months ago would she suddenly have the need to start up again.

[serenitysaves]

if she stoped treatment and then started back up.  It could be she'd rather be on a maintance program with her doctors than shot herion on the streets.  People try to get off everyday, because if they use it as prescribed after some time and a lot of work with themselfs you can start to get your life back and want to get off.  A lot of times people come off way to fast.  This is a stronge drug but can work if it's taken right.!!!!  She could be up to no good but I just want to give you my experence with it....
take care, Robin