i am a submissive, and do sometimes tend towards depression. However i have always found that a good BDSM relationship actually alieviates my depression- the ability to let yourself trust someone is an incredible feeling, much like falling backward and knowing someone will catch you. I think it can often occur that someone with a tendancy toward depression will seek out comfort in a BDSM relationship purely to hide from their own personal issues. But if they are honest with themselves they will know that it is not the submission that makes them depressed but their own self-esteem issues that hold them back.

On the same note i know a man that i would group as a Dom who also tends towards depression. And perhaps i would argue that he finds comfort in the relationship from the sense of control. The ability to control what he loves to protect them...

At the end of the day i think it all falls down to you as a person, not whether you tend towards depression that affects your role in a D/s relationship