Not likely generic issues because the manufacturers have to maintain FDA manufacturing standards, so more likely the anxiety just hits you harder at some times than others.
Same with your IBS since it is unpredictable, so one bad IBS reaction could be unrelated to the clonazepam. How many SSRI did you try, how long, and how many IBS issues did you experience then?
IBS is a digestive problem. It isn't a real thing in and of itself, it's more of a description of symptoms. There are ways of working on it that might fix that problem, though of course there are no guarantees of anything. If you're on medication for the IBS, it might very well be making sure it sticks around rather than helping it to go away, depending on what you might be taking. Seeing a holistic nutritionist and experimenting with your diet might actually fix the darned thing rather than just accepting this as a permanent part of your life. For example, let's say you have a wheat problem or a dairy problem, very common problems people have but don't know they have. If you found that out and it worked and the IBS went away, well, you'd be able to take ssris and handle the digestive problems they present. Sometimes the problem with antidepressants, and also with benzos, is interference with magnesium absorption, and that's important for digestion. So my first thought reading this is, have you ever worked on actually fixing this problem, which is a problem with your digestive system? I mean, you might have tried everything under the sun and none of it worked and you are where you are, but it's possible you haven't tried to do this because your doctor doesn't dive deep. As for the clonazepam, it hasn't happened lately on this site, but some years ago there was a lot of discussion about the generic not working for people. It depended on which company made the generic. Recently this came up as well with Wellbutrin. Generics are not the same as the brand name drugs, they are similar. Many people do in fact find the brand names work a whole lot better, but these days it's not easy to afford them -- the whole health care system has evolved to force us all to use generics and the price of brand name drugs has gone up correspondingly and insurance companies often don't cover them or only cover a small portion of the cost. The only way of finding out, of course, is to try the brand name and see if you get better results. The other thing I'd recommend, and I know you're having money issues with your health care, but psychiatrists generally do this a whole lot better than regular docs. You don't say if you're seeing a psychiatrist or not. A problem with using benzos for sleep is that they actually interfere with normal sleep patterns, so although they are sedating because that's an unwanted side effect of taking them, they are not a sleep remedy and they often do make people drowsy when they wear off. Now, an ssri can be pretty sedating too, so you might have that same problem if you were able to find one that didn't mess up your digestion, assuming you can't fix that problem by changing your diet and lifestyle habits. It's also a bit odd to be taking two pills when it would be cheaper to buy 1mg pills for when you need to take two of them, but that's a small issue. If you feel this schedule isn't working for you, talk to your doc and tell him and try a different schedule and see if it solves your problem, as you seem to feel it does. But as to your basic question, yes, there is a difference between generics and brand names, and some people do notice a big difference, some to the extent that the generic doesn't even work at all. Generic companies do differ in quality and almost all of them are pretty dicey operators constantly getting fined for violations, the worst being Teva.