This is one of those issues that point out how different all of us AN-ers are (in relation to our ANs, and other things too!)
I noticed extra sleeping time long before i was diagnosed, but I have dealt with depression for most of my adult life, so i just wrote it off as using sleep to avoid issues --a favorite diversionary tactic of mine. I do believe that my increasing need for lots of sleep over the year prior to diagnosis (i usually need 9-11 hours ) is a combination of body reaction to AN and my depression.
I decided for myself to ask for a very low dose antidepressant, and have noted a marked improvement in my sleep quality. I must add that I have also made extra effort to talk about this AN with friends, doctor, family etc. (much more so than I usually talk about such personal things). The talking and sharing plus the mild sedative plus regular exercise helps a lot. Thank goodness for friends who have horses (who always need stalls cleaned, horses exercised, etc.)
Definitely mention the sleep issue to your doc. Talk about it with friends, etc. It is miserable to be sleep-deprived, and it is miserable to sleep all the time....another little challenge AN folks have to deal with. And, it is not a sign of weakness to examine your feelings and see if there is any depression (or hidden anger) about the AN, etc.
Lots of great observations about this in earlier posts , of course!!!