Yes, they can be. Self-diagnosing isn't a great idea; lots of non-depressed people have some symptoms of depression. It would probably be a good idea to find someone to talk with though.
I’m just conscious of this because I’ve seen this argument used to justify delaying actual treatment in favour of ‘alternative medicine’.
Basically the counselling/therapy part of the process would be identifying if there's a "real world" root cause to address ahead of going the pharma route and facing potential side effects, and/or the reality of having to go off it later and immediately regressing because the root cause hasn't been fixed.
In any case, I'm obviously not a doctor; neither this post nor the GP should be construed as medical advice.