Some days I feel more depressed and anxious than normal and hence I am not very sociable and talkative like I normally would be. I worry that my friends would take it as being rude to them though I do not do anything that is particularly rude, I am just less talkative and energetic. How could I avoid being perceived as cold or rude to people, especially friends?
No. Making your friends aware that it sometimes happens should be enough, if you want to tell them at all.
There are a few reasons I think that apologizing every time is not necessary.
- Depression tends to be cyclical.
From your question it seems that your depression comes and goes. Your friends, once aware of your depression, shouldn't need regular reminders to appreciate a perceptible, identifiable change in your behavior. Apologizing every time may become tiresome, as there is nothing any of you can do about it.
- Your social perception while depressed is probably not very reliable.
I don't know you personally, nor the manifestation of depression in your particular case. But I would hazard a guess that it is not so different from my own, or those of others I know, in this respect. I imagine that you are particularly anxious about this while in the midst of a depressive episode, and that it is not based on something clearly communicated from your friends. It's plausible, even likely, that these concerns are mostly (if not entirely) in your head. If you want to know how your friends perceive your behavior when you are depressed, you can ask them:
I was a bit out of sorts yesterday. Did it seem like I was being rude to you?
- Whatever the reason, friends should be able to appreciate differences in mood, regardless of the exact reason.
Depression isn't the only reason that people might feel less sociable on a given day, and you don't really owe any particular amount of perkiness or gregariousness to your friends. You're certainly allowed to not feel like going out, doing certain things, or being chatty. If you wouldn't apologize in every such instance (and most people would not), I don't see why you would need to here.
- There may not be an actual problem.
As above, you can ask your friends to find out if there is any issue related to those days when you are less enthusiastic about social interactions. But without that information from them, it's possible (even likely) that you are overinterpreting events. If you are feeling depressed and are quieter than normal, that doesn't automatically mean that your friends are feeling slighted. If they're not upset, then there isn't anything to apologize for.