bipolar disorder or depression?

as for the topic i wish there were an option called "all of the above."

my question is - how do you know if it's bipolar disorder or depression?
i have been diagnosed with ADD and depression a few years ago.
i also have anxiety issues and have really bad up and down mood swings.
and i have OCD tendencies, but nothing too severe.
i'm currently taking zoloft for depression - it helps sometimes, usually when i'm in an "up" mood.
but the past week i've been in a rut & i can't get out!!
recently began researching between the two illnesses, i think i might be bipolar...  and i need help. or someone to talk to. :(

[ILADVOCATE]

There would be a big difference because if a person has depression then their mood swings would vary from depressed to stable (technically euthymic). If a person has any form of bipolar then their mood swings would vary from depressed to stable to manic and there are combinations in between such as mixed states. All of this is clinically complex and should be discussed with a psychiatrist but keep a mood tracker and then print out the results for them. Then if they notice any mood swings that appear to be part of bipolar depression (where depression is the general concern but there are episodes of mania as well) they could update your diagnosis and treatment within their discretion.

[paranoid_cataclysm]

Bipolar disorder involves you cycling between depressed to hypomanic/manic and sometimes mixed states which is depression with the sped up quality of mania, when you're having mood episodes.  Hypomania is a lite version of mania, so to speak.  Mania can involve destructive behavior to oneself such as gambling, running up credit card bills when you have no money, hypersexuality, decreased need for sleep, racing thoughts you can't keep up with, pressure to talk, rapid talking, impulsiveness, euphoria, gradiosity, etc.  When a person has a manic state it's usually pretty obvious something is going on with them and usually can end up with a hospitalization if the person is around people who are educated in these matters.