From my experience the tax implications while important are usually only a small part of the potential problems....
If your name goes on the account with your parent, and (sorry to be morbid here) your parent passes away, the proceeds of the account do not form part of your parents estate, but pass to yourself. That may be exactly what you and your parent want, but I've seen so many rows afterwards among families when they feel they are entitled to their share of that account. It's just something to be aware of.
To get around the problem there is a bank document you and your parent can sign, which gives you authority to sign cheques/debits on the account, but your name doesn't actually go on the account. This often suits the parent, the co-signer and the family best as the proceeds of the account then form part of the parents estate. (again, sorry to be morbid).
Hope that's of some help.
Regards,
BM