Why does my personality change?

first off i have major depression. but i go from being totally withdrawn (not socializing with customers at work, i feel i dont have the ability to) to being my normal witty, self. How can i have great levels of intelligence and wit one second, and be reverted to nothing the next?

Its almost as if my mind were fatigued as well as my body, im always tired.

for this reason im going to try adderall i hope it helps, but why does my personality change like that? I know im capable of being social but i cant snap out of the dulled out feeling!Why does my personality change?
Anxiety often accompanies depression. So you may naturally be an extrovert, but become more introverted and shy when around people you are uncomfortable with.Why does my personality change?
maybe you should talk to a doctor but my advice don't take adderall it messes with the chemicals in your brain...which in the future could make your personalitys change even more
Personally, I would assume you are introverted. It could be because, even though you can socialize with others, you feel alone. Although you are adequate at socializing, you don't feel like you connect or you are just completely different than everyone else. Maybe you have a feeling that you'll never be able to connect with anyone and enter into that depressed, lost world. Sad thing is you just have to wait it out, although you know another cycles waiting in the future. Don't take adderal thats compromizing yourself, save what uniqueness you have youll regret it later
I don't think your personality changes, I think your mood does. And I think it's because you're sick of your boring, recurring life. Try something new. Get your spirits up, do different things especially the ones that are far from your daily routines. That way, you always have something to keep you excited and bouncing.
You need to have professional advice. Also from what you describe is signs of borderline personality disorder with symptoms of depression that lead to the chronic tiredness, a common symptom among people with severe depressive disorder. Keep in mind that many intellects suffer from what you have described and the only way of a proper diagnosis is seeing a psychiatrist. Good luck!