One of the big challenges I have in working with families who have bipolar disorder and things like that is that there is a certain level of difficulty in following up. And that's probably true for all longitudinal studies, but with kid studies, it's so important to do follow-up because really you're studying development, and so you want to study these kids at another point in time, when they're young adults or adults.

And often just by the nature, I think, of research, but also because of the population, it's difficult. Because these families can be moving, a lot of times they're single-parent families, a lot of times a parent might not be doing well enough to be able to bring the child in or even to respond, or maybe for some reason just drop out of the study. And so it's really hard to do longitudinal studies in this population.

I think what makes it easier and what we do now, what I would have done at the beginning — you have to really get them invested into your research. And so this is actually something that we did do. We started with a newsletter, and we sent out a newsletter every year to two years so that people get this information, so they're part of the research, and they're invested in it.

We also try to offer any kind of clinical services that they need. So that we put a priority on the folks who are doing research because we have to make a cut-off somewhere; we're not a big clinic. And so we said, "Well, in order to fulfill our mission, we're going to put a priority — if you do research, then we're probably more likely to pick you up and follow you clinically after that." And so those are ways of keeping folks not only invested, but also physically close by and able to be contacted so you're always knowing where they are. It's really important for these kind of studies.