Kimball’s graphic memoir, And Now I Spill the Family Secrets (HarperOne, Apr.), tackles her family’s legacy of mental illness.

How did you balance collecting memories and undertaking research in writing your family’s story?

I had my memories floating around and tried to put them in order. Then I tried to fact-check them. The thing I loved the most was when I started discovering documents—that detectiving. Our memories change, but records can be wrong, too. My grandmother’s birthday was recorded wrong. Can you ever really say exactly what happened? I want the answer to be yes, but I don’t know.

What surprised you in your research?

There’s so much more information that I want to dig up. It’s addictive. A lot of the hospitals my grandmother went to are now defunct. It raised this question of how we treat people with mental illness in our culture. I feel like a different person than when I started this book. The generational impact of mental illness was something that I realized toward the end.

Can you talk about your choice to focus your drawings on objects and places rather than people?

I think of the book as a memory map, and when I think of memory, I picture a shirt or a shoe or a smell, but not my brother’s face. I wanted to use the illustrations to create this environment that was immersive.

When writing about your brother Ted, you give him space rather than judging or diagnosing his paranoia and conspiracy theories. Why did you take that approach?

I’m the one in the family who asks him the most questions rather than just saying his versions are impossible. We have this foundation that, even when we fight, is still there. He has different motives, and he knows that I have different motives. In his mind, he’s announcing his stories to the world. But it’s a conversation that requires maintenance.

In what ways did working as a professional illustrator prepare you to draw your own story?

Clients often want what’s most beautiful. Sometimes when I was facing difficult passages where I didn’t know what to represent, I could think about what was most beautiful. I could fall back on that. Like, I feel such warmth when I think about the houses I lived in with my mom. It was a disaster, but I felt safe there. I could make a mess and it wasn’t a big deal.

What do you hope for the book?

That it’s helpful. That the pictures make it accessible in a way that a tome about mental illness isn’t. So many books saved my life at different times, and I kind of wish a book like this existed when I was younger.