“Little Disasters,” premiering Thursday on Paramount+, is both a glossy psychological thriller and a classic British whodunit. At its center is Diane Kruger’s Jess, a mother accused of seriously harming her baby daughter.

To play Jess, a mother of two grade school boys and the baby, Kruger, 49, had to continually balance emotional extremes through months of filming the six episodes.

“Excuse my English but it was a bit of a mind (expletive),” the multilingual Kruger acknowledged in a virtual interview. “I would have to go from one extreme emotion in the morning from, like, Episode 4 to go into a happy flashback from Episode 1. So, emotionally and physically you always have to anticipate where this puzzle is going to fit in within a really extreme, heightened emotion.”

Jess, we learn, is given to flashes of horribly realistic images of what might go wrong. “They’re just,” Kruger explained, “intrusive thoughts, which are very severe form of postpartum depression.

“I met Sarah Vaughan, who wrote the book and who was very present while filming. She revealed that my character was based on the personal experience that she went through when she had her kids.

“And I’ve had a few girlfriends in my circle, who have struggled with postpartum, if not to this extent.

“So that was interesting: Really leaning into what this condition can bring, the scariness of the darkness that comes with it.

“My daughter was five when we did this. So I didn’t have to look for very long and hard to feel a commonality, something that I had at least experienced to a certain extent. It helped me immensely.”

Is there a special responsibility when actual kids are playing your kids for two or three months?

“Yes, it’s a huge responsibility. It’s never easy. Obviously, it depends on the subject matter as well but clearly this wasn’t the kids movie.

“Kids are very intuitive. If they want to be on set, it makes it easier. But they don’t have the — what do you call it? — the wherewithal to really understand the depth of some emotions. They’re very just reactive to what’s going on.

“For example, I think about the last scene with its big reveal in the park. I remember going on long walks with the little boy who plays Frankie (Jax James), because he’d never been on set and he was going to watch a bunch of adults yelling and screaming and crying.

“And we needed him to be emotional as well. It takes trust. You have to gain that trust and it’s a big responsibility.

“You don’t want to obviously hurt or scar them for life. It’s a funny job for a kid, for sure.”

JJ Fields, Jago, Diane Kruger, Petra and Jax in a scene from “Little Disasters.” (Photo courtesy Paramount+)