i know two people with adhd and neither of them are lazy or don't do homework.
one of them keeps losing jobs however, but he always gets a new one, because he's bad at math, and never finished high school, and not the sharpest tool in the shed, however, he's a sweet guy, with good intentions. he's just not very mature, but is still responsible.
the other one studies at mcgill, and just is really eccentric, she has to get good grades because that's what her parents expect, and she studies, and without the meds. she got expelled in high school for running around on the roof of her school(it was tiny and private, built like a house) but that's really the extent of her. other than that, she's just a hyperactive person, always boucing, and on the move, saying weird things, and has a really wild imagination.
neither of these people are lazy or unmotivated due to adhd.
i love people who misdiagnose things so easily.
if you're lazy and don't do school work, it's not adhd, you're just a teenager, and your hormones are going apeshit. if you're young and full of energy, or your sibling is and loves to play and run around, that's completely normal.
it's only when the actions are to extremes is that it's really a case of it.
bipolar is a completely fucked up depression, and saying you want to do shit and don't doesn't mean your bipolar.
however, you can be depressed, which causes social withdrawl, lack of interest, irritability, and sleepiness or insomnia etc.