The way I tend to differentiate between hormones and true depression is by tracking my cycle. The week before my period can be quite bad so if I feel depressed and its that week I ride it out. If there is, again I try to ride it out. If these reasons fail to give me a reason, I'd probably try to see my dr.
Clinical depression can be a medical problem that only medication can help.
Hope this helps. I have a question. I feel like I could sleep all day. Thanks for listning.