Deppression tends to be quite a common thing amongst the general concensus of bodybuilders, but not all.
Usually the most contributing factor towards deppression is lowered natural hormone levels. As your body is depleted of
steroids (Test, Deca, etc) your natural male hormone levels have not yet increased and you may find that the female hormone is elevated due to a natural response within the body. Another factor is the increase of your bodys cortisol production (ask an athmatic how they feel on this stuff).
secondly and most importantly their is the Phsycogical response to withdrawal, you know "I'm not getting bigger","I'll probbably lose size" etc. To pin-point one particular reason is almost impossible due to the fact that each individuals genetic and phycologocal make-up is different.
ANSWER: Yes it is common and normal in 7 out of 10 bodybuilders.
The deppression usually lasts an average of 3 to 6 weeks f you find that it's a majour problem and like a late freind of mine decide it's all too much for you PLEASE SEE A COUNCILOUR!
But usually its a normal re-adjustment to the bodys endocrine system and life is good.
Take and Relax