In "There Is Not Currently a Problem," the seventh episode and midpoint of its second season, FXX comedy You're the Worst does something I'm not sure I've ever seen TV do so well: It makes clinical depression understandable.

It does so by grounding that depression in a character we already love, who's always been troubled but basically fine. And it adds a nasty edge to one of the things that's always been funniest about her, her ability to immediately find the worst thing about someone, the point where they feel the weakest, and turn it into a snide joke. It makes depression at once sympathetic and terrifying, and it shows just how exhausting living with the condition can be.

It also brings the series to another level. You're the Worst has been dancing around this revelation for a while. The first six episodes of this season indicated something was wrong with Gretchen (the series' female lead, played by Aya Cash), but not specifically what.

But even in season one, her hugely messy apartment and her occasionally erratic demeanor suggested she was suffering from something far more extreme than garden-variety self-loathing.

Now, though, her secret's out in the open. Her boyfriend, Jimmy (Chris Geere), knows, and he's determined to fix it. But if Gretchen knows anything, it's this: She can't fix this. She can only manage it. Maybe.

Television is a horrible medium for talking about mental illness

One of the things about mental illness is that it never truly leaves a person. It can be medicated, and talk therapy can definitely help. But if someone is clinically depressed, she's always going to be clinically depressed. She'll have peaks and valleys, sure, but you can't tell a story that's all peaks. That's just bad drama.

This is absolute anathema to television, which thrives on change and on characters either overcoming their obstacles or eventually falling prey to them through means of their own making. As an example, consider The Sopranos, where Tony's panic attacks gradually subsided as the series went on, because he was unable to confront the real roots of his anxiety and depression. To do so would be to admit his own weaknesses and his own culpability in egging on those conditions. So he drifted on, blithely trying to keep a cork in a big, rage-filled bottle.

Television generally takes that approach to dealing with mental illness. It's a problem, and maybe the characters always know it's a problem, but they also can't constantly be struggling with the same problem week after week, lest the viewer become exhausted. On the '90s soap Party of Five, for instance, Kristen, one of the main character's love interests, fell into a bout of depression, but it was largely treated as something she would overcome with proper care and treatment. The idea that it might never go away is just too much for a TV show to deal with.

For an example of a show that I think generally handles mental illness well, turn to Showtime's Homeland, where the lead, Carrie Mathison, struggles with bipolar disorder. The show too often suggests that Carrie's fits of mania drive much of her spycraft prowess, and "my mental illness makes me a great crime solver!" is an unfortunate TV trope. But when it digs into how horrible Carrie can be to those around her, and to herself, in her depressive phases, the show finds the long, grinding process of learning to live with mental illness.

Plenty of viewers have complained about this (especially connected to a recent episode where Carrie went off her meds yet again), but there's an admirable stubbornness to it. This is what it's really like to have bipolar disorder. Most people look away. Will you?

You're the Worst tries to make this funny — and somehow succeeds

The centerpiece of "Problem" is a scene in which Gretchen tells every single one of her friends exactly what she thinks of them. Now, it's not actually what she thinks of them. It's her depression feeding her the worst thoughts she's ever had about them, then blowing them up even further. It's her brain causing her to drop a nuclear bomb on her life. (Amusingly, one character who's an improv comedian seems to treat the whole thing as just another comedy game.)

But this scene will ring devastatingly true to anyone who suffers from depression or loves and cares about someone who does. These moments of seemingly over-the-top rage happen, and they're usually followed by even deeper trough of self-loathing. Gretchen doesn't really hate all of her friends. She hates herself.

What makes the episode work until the centerpiece scene is how expertly writers Stephen Falk (also creator and showrunner) and Philippe Iujvidin convey that something's not right, even as everything, outwardly, seems to be just fine. This is an impeccably crafted episode of television, one that takes place in a single location and includes lots and lots of little motifs that indicate things are going very wrong.

In particular, there's a mouse that Jimmy becomes obsessed with catching. It could too cutely stand in for his need to fix the problems in Gretchen's life — he doesn't yet know she's depressed, but does know she goes out at night to cry in her car — but when the episode ends, the mouse, which he believed to be dead at his hand, skitters back into the wall. You can't get rid of these things. You can only turn a blind eye to them, until they're staring you in the face.

But in terms of raising tension, the episode also lets Gretchen be off, wearing sunglasses inside and drinking too much and dancing to music that's not even playing. She's staving off something that's chasing her, but she won't be able to forever. You can't escape depression.

The centerpiece shouting match is followed by a sweet scene where Gretchen's oldest friend, Lindsay, who's received many of Gretchen's worst insults, goes into her bedroom to ask her if it's "back," if this will be like sophomore year, when she didn't leave her dorm room for weeks. Gretchen, tearfully, nods. Jimmy can't find out, she says. But Lindsay points out that Gretchen's shared more of herself with Jimmy than with anybody else. He needs to know about this if they're going to have a real relationship.

That's the cost of loving someone with clinical depression. It's understanding that they will go out of their way to make you feel, at times, like the smallest person on the planet, and then having to overcome that to realize they're not really yelling at you for who you are, but for loving them. Lindsay knows that. Jimmy is about to find out.

Depression is a ravenous beast that slumbers, sure, but never really goes away. When you're in a relationship with someone who suffers from it, it's the unspoken third in the relationship, the thing you try not to talk about. Maybe, if you're lucky, it will go hide in the wall for a while. But it always comes back out. It has to.

You're the Worst airs Wednesdays on FXX at 10:30 pm Eastern. Watch previous episodes on Hulu and FXNow.