Excessive Oil Use

I have a 1998 Chevy Prizm with about 160,000 miles on it that I acquired recently. It goes through massive amounts of oil. I don't have a good measurement but am putting in about 1 quart per every two hundred miles I drive. I've looked online and this is apparently a common problem with this model and year. The most common recommended solution seems to be just keep adding oil but I have teenagers driving this car that are not always good about checking the oil and I'd like a good fix. Has anyone else fixed this problem? I found one individual who recommended adding Seafoam to clean the pistons and rings. Has anyone tried this? Did it work? Do I need to replace the piston rings? Will replacing the head gasket take care of it? What did you do? Any input would be great!

Thanks.