Are you asking whether you should seek help in general? Or how to tell whether you should see a doctor versus a counsellor?

If you're asking the second question, it depends on whether your depression is most likely endogenous (caused by a chemical imbalance in your brain) or situational (caused by life circumstances). In both cases it's a good idea to see a counsellor for therapy, but if it's endogenous depression, it's important to also see an M.D. who can prescribe you medication.

Signs that it may be an endogenous depression:
- you have a family history of depression
- you have loss of appetite/weight loss
- there is no trigger for your depression that you can think of
- you have sleeplessness, or wake up too early in the mornings

Whatever your symptoms, it's never a bad idea to see both a counsellor and a doctor, if you can.