Do IPAs cause worse hangovers? I usually drink strong Belgian Ales, particularly Triples, Quads and Trappists, so I'm no stranger to strong beer.  But I've noticed that I get far, far worse hangovers when drinking IPAs.  

Is there anything about IPAs that would make this possible?  The lower quality places like ask.com or Yahoo answers usually say no, that only ABV produces hangovers, though one source did seem to imply that IPAs have special ingredients that make this a possibility. 

So I want to ask the experts here: do IPAs have ingredients that other strong beers lack, that could exacerbate hangovers?
Although as Bill said it can be down to a persons chemistry. One reason for you finding that IPAs affect you more could be the higher hop content in a Pale Ale (IPAs in particular). Hops (the oils) can have an effect on brain chemistry, that affect can be positive or it can be negative!

Some people can actually have alergic reactions to hops, or even beer in general (poor them, see this). Where as I suffer from some nasty migraine problems and actually find that well hopped ales alleviate some of the symptoms (not that I use it as a reason to drink!!).

So to sum up is it possible that you find that IPAs cause you to suffer more in the morning because you have a slight intolerance to higher hopped beers. Where as your fellow drinkers do not.