The best hint that “Crazy Ex-Girlfriend” means to reconcile the “crazy” in its third season lies in the theme song.

With every season of Rachel Bloom’s rom-com musical series comes a new opening credits sequence. But while the catchy expositional intro of Season 1 and the bubbly but utterly dark Busby Berkeley number of Season 2 make good first impressions, Season 3’s opening musical mashup is a head-scratcher: Four Blooms, each an avatar for different styles of music, sing in tandem about different flavors of crazy, while a fifth, very perplexed Bloom watches their performance on YouTube.

Country singer Bloom shatters windshields with a baseball bat. Diva Bloom is crazy in love. Rock 'n' roller Bloom likes girls with crazy bedroom habits. Rapper Bloom thinks you should avoid the other three Blooms at all cost. Gathered together on the same stage, they’re the sum total of her character, the increasingly unhinged Rebecca Bunch.

Try as they might, they can’t find a cohesive conclusion to their joint anthem, each of them looking at the other as if for an answer to a rhetorical question. That’s the point, of course. For two seasons now, we’ve watched Rebecca labor endlessly to rationalize her unique craziness but fail to find a way of coping with it. She can’t possibly.

If “Crazy Ex-Girlfriend” used its first two seasons to lay the groundwork for addressing Rebecca’s underlying issues, Season 3 throws them into sharp, painful relief, which gives the show’s overarching narrative tangible dramatic heft. The experience of watching Rebecca’s misadventures in stalking has changed. Prior to now, “Crazy Ex-Girlfriend” was about watching an oblivious train wreck coming off the rails as the conductor sat blissfully daydreaming at the wheel. Following Rebecca’s failed wedding to Josh Chan, the undeserving object of her love, the series is now about the painful task of cleaning up in the wake of emotional calamity.

And it’s beautiful. You can still expect the same screwball zaniness from “Crazy Ex-Girlfriend” as before, of course (though with one fewer dance numbers per episode than there ought to be). What’s new here is the dramatization of the process people go through when they’re no longer able to justify their actions and must confront the truth of who they are. We always knew Rebecca is crazy, for lack of a better word (the show’s title is, in her own words, sexist, and while we’re at it, “crazy” is a worn-out and unacceptable pejorative). Rebecca knew, too, but on a primal level rather than a surface level. Now she irrefutably, undeniably knows, and watching her deal with it is as joyful as it is achingly true.

Here’s a fun exercise: Try telling someone you know and love who has behavioral health problems that they have behavioral health problems. It’ll go poorly. Take Rebecca’s full-nuclear reaction to her West Covina crew when they try to stop her from dodging self-accountability by running away to Rome with her boss-cum-partner-in-revenge-cum-lover, Nathaniel. She doesn’t stop at telling them to butt out of her business. She mercilessly lays their own blemishes bare. Watching her shred Heather, Paula, Darryl and Valencia is horrifying, but they understand. Rebecca felt cornered, attacked and worst of all judged.

When you’ve spent your life explicitly denying your inner demons, hearing people voice their concern for you in the fashion of “Crazy Ex-Girlfriend” is very much like hearing those people tell you that there’s something wrong with you. No one actually says it. Rebecca senses it as subtext, and it chafes her.

She thinks she’s fine the way she is, that everyone else, especially that jerk Josh, is messed up, not her. But eventually Rebecca bottoms out, burns her bridges, and then, only after attempting suicide on a commercial flight in the final soul-shaking sequence of Episode 5 (“I Never Want to See Josh Again”), does she accept that she needs professional care, emblemized in the musical number “A Diagnosis” in Episode 6 (“Josh Is Irrelevant”).

In keeping with her character, Rebecca seeks out a second opinion on the diagnosis handed to her by her new doctor, Dr. Dan, who tells her she has Border Personality Disorder; the statistics and traits and treatments that come along with it are too dark, too much for her to handle at first.

But Rebecca’s struggle with her diagnosis is “Crazy Ex-Girlfriend” at its best. It’s scary, to sit in a room with a stranger and have them tell you things about you that you’ve always been aware of but never felt comfortable enough to admit out loud. It’s also freeing and, in a way, even validating. Facing the parts of yourself that you fear demands you see yourself in unflattering light. (This is true for Rebecca especially, because as great as she is, she’s got a rap sheet that spans the country.)

But once you do, you realize your fear is a self-fulfilling prophecy. The more you fear those parts, the more influence they wield over your life. Confronting them means understanding them, which means understanding yourself. In “Crazy Ex-Girlfriend,” as in real life, that dynamic is actually palliative. Suddenly, her the ebb and flow of her life makes more sense. Suddenly, there’s a name for this side of her that she’s so afraid of. Suddenly, she belongs.

“Crazy Ex-Girlfriend” is now on its brief winter hiatus, and we’ve only had one episode for Rebecca’s diagnostic discoveries to really sink in and start changing who she is. That episode, “Getting Over Jeff,” focuses more on Paula, with a side arc involving Josh’s latest idiotic attempt at growing up (because nothing says “grown up” like emulating Tom Cruise in “Cocktail”). But we can already see the change in Rebecca, ever the overachiever, as she strives to get a handle on her dos and don’ts, her triggers, what activities and indulgences she should avoid and which she should embrace. (Turns out that staying somewhere in the middle of extremes is her best bet. Who knew?) The healing has already started.

Maybe “Crazy Ex-Girlfriend” isn’t exactly a serious show, but unlike other shows that hinge on behavioral disorders, a’la the very good “Mr. Robot,” Bloom’s story handles its mental health element with honesty rather than fantasy or melodrama, and that honesty is already taking the show to wonderful places.