How long do the euphoric highs last? Hours? Days? Weeks? During your highs, in addition to the love of shopping, do you have any of the following symptoms:
feel more talkative and talk faster
decreased need for sleep
the feeling that you're on "top-of-the-world"
the feeling that you can do anything
an increase in the number of projects you're involved in
the feeling that your mind is sharper and clearer
irritability when someone doesn't agree with you or your plans
and/or hallucinations and delusions?
If so, this is probably (hypo)mania, especially if it lasts a week or longer. But, if you find that you quickly go from loving everyone to wanting to kill yourself the next, this may be BPD. For BPD, do you find that you:
have trouble finding your identity
have a need to be loved to the point where you feel intense jealousy and neglect
feel that cutting yourself would let out your emotional pain
go from saying, "I love you" to someone, to "I hate you" within minutes?
These are classic symptoms of BPD. That's the tricky thing about distinguishing BPD from manic-depression: you have to really understand the "highs". If you have any more questions, let me know!