Longitudinal follow up of folks is difficult no matter what, and these families are under, oftentimes, a great deal of stress. The parent may have depression or mood disorder or substance use disorder, so that adds an extra challenge to it.

The ways that we've tried to help manage that problem, we've sort of taken a multi-pronged approach, and one is have really well trained interviewers who are clinically savvy, have worked with kids and families before, that our coordinators are very sort of outgoing and warm.

We've learned from some of our other colleagues here at the University of Pittsburgh about things that families respond to, like sending out birthday cards and holiday cards for some of the families. Those kinds of things are both kind of heartwarming, but also it really keeps them attached to you.

The other thing that we've done with our clinical populations, kids that are actually receiving treatment, is we developed our own treatment program, a specialty treatment program here at the University of Pittsburgh, the Child and Adolescent Bipolar Services Clinic.

And a lot of the kids who are in our longitudinal follow-up study receive treatment with us or have in the past. And if you're able to offer them something back to the families and children, they're oftentimes more likely to work with you doing research studies.

And it allows some synergy, too, because families will, if they're coming in for a doctor's appointment or therapist appointment already, they're more willing to add on an extra hour-and-a-half assessment or two-hour assessment. It's not as hard as having to come especially just for this research assessment.

We've also found that some small monetary incentives can be helpful, too. I mean kids like to earn a little bit of money. And I mean, you don't want to be coercive with it, but they feel kind of proud and excited if they're able to do something and then they also get a little bit of money. It sort of makes them feel good.

We also tend to reward folks a little bit more each time they come in, so doing more follow-ups gives you a little bit more incentive, knowing that it's kind of hard to stick with things over time. So that's one thing that we've learned from other longitudinal studies that have been helpful. We didn't invent that, and we've learned that from other folks.

But it does tend to help. If you're coming in for your seventh visit, which sometimes may be the case in some of these studies where we follow kids every six months, it takes something to sort of say "Okay, let's do this again and do this well." So that little bit of extra incentive can be helpful.