Can a wizard run out of power?

Question

Similar to the question about the "wand power", I'm curious if a wizard can run out of power by other means than death.

This quote lead me to ask my question especially because Ariana had some issues with handling her magic powers and with her character there are always mentioned squibs:

It destroyed her, what they did: She was never right again. She wouldn't use magic, but she couldn't get rid of it; it turned inward and drove her mad, it exploded out of her when she couldn't control it, and at times she was strange and dangerous. But mostly she was sweet and scared and harmless.
_{Harry Potter and the Deathly Hallows, chapter 28}

In some other movies/series/books there's always at least a tiny mention of "draining" a wizard's power dry. So, if not naturally i.e. by having mental issues (Ariana still had magic powers in some crippled form I presume, until death), does JK state anywhere some other means how would a wizard run out of power directly or by an action of other wizard? Probably a plothole around Ariana's character?

Maybe there was a person in St Mungo's hospital or something?

Answer 1

I am unsure whether this is a case of a wizard losing their power permanently, but in Half-Blood Prince, Dumbledore says:

"Of course, it is also possible that her unrequited love and the attendant despair sapped her of her powers; that can happen"
_{Harry Potter and the Half-Blood Prince, chapter 13}

This would seem to suggest that it is possible for a witch or wizard to lose their powers.

Being exposed to Dementors for an extended period can also cause a wizard to lose the ability to use their magic, although this certainly isn't permanent.

Answer 2

As far as I can remember, magic is not a resource within a body of a wizard. You can't drain it. You can compare it to gravity. It's a force that is all around us. The difference is that wizards are able to manipulate that force to a small extent without a wand, like Harry making the glass disappear in the zoo. They need a wand to manipulate that force on a bigger scale. The wand acts as a catalyst, a tool.

So to answer your question, no, a wizard can never run out of magic. But he can lose his ability to manipulate and form it. And the ability to manipulate magic differs from person to person.

I also don't consider Ariana's story a plot hole. I think that wizards never stop using magic. They use it automatically when they get angry or emotional. The problem with Obscuros is that they don't let the magic they used or created manifest in the world. They kind of swallow it and that might damage the mind and body. That could pretty much explain your quote, too.

[...]She wouldn't use magic, but she couldn't get rid of it; it turned inward and drove her mad, it exploded out of her when she couldn't control it[...]

She wouldn't use magic as in she doesn't let it manifest, therfore it's stored within her and she could not get rid of it. Whenever she lost control of herself, it burst out.