Absolutely it is.
Anger is seemingly a part of many depressions and it also seems that it is the anger that causes the depression as the person (including me) has been taught as a child to not be angry. So it turns inwards, punishing yourself when the anger should be directed outwards.
In nearly 50 years of suffering this as a big part of my own depression though I have yet to get an answer from any adviser, doctor, psychiatrist or self appointed expert as to how to express that anger safely so it does not turn back on itself, on you.
There are many who talk about punching bags and similar ideas but these do not work.
So it is part of the yet to be found solution to many depressive illnesses to find a way to express that anger/rage in a healthy way at the time it is relevant and not store it inside your head for yeards and decades.
I do express my rage when it arises thse days which is really why I isloate and stay at home mostly. You see when I do let it go anything could happen and I could hurt someone or even myself in such a state.
The causes of depression are limitless I'm afraid. What may depress me could mean nothing to you. Similarly with rage. I get into a rage when forced to wait on telephone calls for people who then fob me off to someone else who then tell me there's no problem when there is. Etc.
You need to identify the causes yourself or in conjunction with a doc or therapist.
Hi, yes it is, look at the top of the page and under health topic look up depression. Hope this helps.