“Black-ish” kicked off its second season with the exhilarating musical episode “Juneteenth,” an incisive examination of the legacy of slavery and the progress America has not made in the arena of racial justice.

The second episode of the season is in a different key, so to speak. It takes on an important topic, but one that is often spoken of in whispers, if it’s talked about at all. And it’s entirely appropriate that “Mother Nature,” which depicts Rainbow Johnson’s experience with postpartum depression, airs on World Mental Health Day.

In the episode, the difficulties she experiences after giving birth to baby DeVante overwhelm Rainbow Johnson (Tracee Ellis Ross). Her postpartum depression affects the entire family, and at first, everyone — including Bow — is unsure of how to proceed.

The idea for the episode came from writer and executive producer Corey Nickerson, who brought up her own experience with postpartum depression in the “Black-ish” writers’ room. She quickly learned that many other staffers or their spouses had experience with it. One of the many facts about the condition that is gracefully woven into the episode notes that one in seven women goes through postpartum depression after the birth of a child.

And yet it’s a diagnosis that many new mothers don’t know about and aren’t prepared for. It can be even harder to recognize in women like Bow, who have had children but did not experience postpartum depression in the past.

“It was something that none of us had been warned about or had been” really aware of, Nickerson says of her circle of friends and colleagues. “Doctors didn’t really tell us it was a possibility. I’d heard of it. I didn’t really know what it was. So even when I was going through it, I didn’t really know exactly why I wasn’t right.”

Once the discussion was underway among “Black-ish” writers and producers, it was only a matter of time before the show brought it into the storyline involving the most recent addition to the Johnson family.

“We have this great character, a strong, great mom, a successful doctor,” Nickerson notes. “Why don’t we try to show women that it’s OK to be dealing with something like this and still be good moms?”

Tracee Ellis Ross says a couple of key scenes between Rainbow and her mother-in-law, Ruby (Jenifer Lewis) were, in many ways, an actor’s dream: They were challenging and filled with real, raw emotions. But she says that shooting the toughest moment in the episode — a very painful confrontation between the two women — left her drained.

“It was a heavy scene,” Ross says. “At the end of one of the takes, I couldn’t stop crying for real.”

Ross, who says she has “touched depression enough to have a place to go” in her performance, relished the opportunity to do what “Black-ish” has always done: Take on an issue of importance and air out a variety of views on it, while showing the resilience and adaptability of the Johnson family.

“I feel like we earned those moments — the heavier moments,” Ross says. “Even when you get to a scene like that, the audience has been right with us. We’ve all been laughing at how horrible Ruby is to Bow. It’s been hilarious for three years, but [an action Ruby takes in ‘Mother Nature’ leads to a much more serious dynamic]. And I think also the episode was a good way to introduce a topic that is not talked about. Postpartum depression is something that is extremely undiagnosed and way more common than any of us are aware.”

Because Nickerson was personally well-versed in the topic, and because she had additional research at her fingertips, the episode was not actually one of her more difficult assignments, she says.

“We were trying to portray the struggle of a woman having postpartum depression but who doesn’t want to ask for help, and who isn’t used to being in a position where she needs to,” Nickerson says. “She has a supportive husband who wants her to get better. I could relate to all of that. [Through research I understood there were people] who didn’t believe that it was real. I could see Ruby being that person. So it was just it was very obvious the roles that people would play in this household in the episode. It felt very natural.”

In a secondary storyline, the Johnson kids try to take on some household tasks in an effort to make their mom feel better.

“When something is not right in your house it affects everyone — the whole house is out of whack,” Nickerson says. “So it seems natural to show that the kids are a little bit afraid, and they are trying to do things, in a comedic way, to make everything OK with their mom. ‘If we are able to baby-proof the house, then that maybe that’ll cheer her up.’ There’s a lack of understanding about what she’s experiencing, but they do know that she’s off.”

In her performance, Ross was conscious of not wanting to portray’s Bow’s situation in a monochromatic way.

“The biggest thing I was worried about was finding the arc, so that you don’t play your whole deck in the first couple of scenes,” Ross says. “So that you’re not crying in every scene and there are different kinds of cries, all of it grounded in real tears. That was the thing that was hard — grounding it all in real feelings but then putting the layer of comedy on top of it.”

Both Nickerson and Ross spoke about the care that has been taken with Bow’s character throughout the run of the show. While elements of the ABC comedy are quite traditional, no one at “Black-ish” ever wanted her to be a one-dimensional sitcom wife and mother.

“What is interesting about her is her selfhood: It’s not that she’s a mother, it’s not that she’s a wife, it’s not that she’s a working mother, it’s not that she’s a doctor — she’s all of those things,” Ross says. The show often deals “with race and identity and culture and tradition and what that means. But there’s an underlying narrative on our show that I find so interesting and challenging, that really deals with who a woman is in this world now.”

And as resilient as any mother thinks she is, there are always media images and post-birth stories that can make her feel inadequate, which is one of the themes of the episode (as well as other elements of Bow’s recent storylines).

“I remember parenting magazines coming out and showing a woman at the park rollerskating while she’s nursing, and it’s just like, ‘Look at how easy this is! I’m wearing all white!’” Nickerson says. “There’s all this pressure from society to be this perfect thing. People say that it’s supposed to be the happiest time. And for a lot of women it’s the hardest time, and they feel alone and like they’re doing it wrong.”

Nickerson adds, “If someone can watch the episode and say, ‘I didn’t know that it was OK for me to feel this way and to get help,’” then “Mother Nature” will have done its job.

“Black-ish” airs Tuesdays at 9 p.m. on ABC.