John Green’s latest young adult novel focuses on a teen with mental illness. Unsplash

High-school junior Aza Holmes, fan of bad poetry, Dr. Pepper, and her beat-up car Harold, has, like every normal ado­lescent, some irra­tional fears. But hers are worse. She has intense ger­mo­phobia, which keeps her from other normal teenage activ­ities: friend­ships, adven­tures, and espe­cially kissing her first boyfriend.

Aza’s struggle to escape the “tight­ening spiral” of her anxiety dis­order is the focus of popular young adult fiction author John Green’s latest novel, “Turtles All the Way Down,” a coming-of-age story through which Green serves as equal parts author, teacher, ther­apist, and poetry pro­fessor. I read the story for a Christ­mastime walk down memory lane. I emerged dis­ori­ented, won­dering whether as a teenager I, like Green, had con­fused relatable life advice with good sto­ry­telling.

In classic YA fashion, Aza is a smart, elo­quent teenager with real problems — and inter­esting ones. She obses­sively researches bac­teria that live in the human body. She picks open a callus on her thumb, cleans it, and applies new ban­dages, over and over again. She could be played by a young Emma Watson; she would not be out of place in “The Perks of Being a Wall­flower,” a novel-turned-movie in the same coming-of-age vein from a few years ago.

By novel six, there is a rec­og­nizable brand to Green’s char­acters, and Aza and co. partake in typical Green­nesses: They are pre­co­cious, artic­ulate, honest, emo­tional, troubled. They come from broken homes at mediocre high schools in non­de­script cities. But they love their small fam­ilies and friend groups some­thing fierce, and they talk with them about poetry, phi­losophy, and cos­mo­logical models with equal earnestness. Aza’s new boyfriend Davis has a poetry blog, which fea­tures Shake­speare, Woolf, and Plath; he writes poems with odd rhyme schemes because “That’s like life; it rhymes, but not in the way you expect.” He and Aza use metaphors to shape their struggles; Aza adapts Yeats’s “The Second Coming” by describing her mental state not as a “widening,” but a “tight­ening gyre.”

Pre­co­cious, perhaps, but not foreign to the teenage expe­rience. Having put in some time as a pre­ten­tious teenage girl myself, I can attest that glossing ado­lescent crises with classic lit­er­ature is a coping mech­anism for the few, the chosen, the afflicted among book­worms.

But in popular young adult lit­er­ature?

Well, yes, and here, the risk of didac­ticism works — neither the book’s char­acters nor its author is dumb, and at least the kids are learning some­thing while thinking about serious problems like teen mental dis­orders.

It is not in Green’s (admit­tedly pre­dictable) cast of char­acters that my dis­comfort with “Turtles” lay. And it is not the glo­ri­fi­cation of heavy subject matter of Aza’s mental struggles. (Green writes of mental illness in a way that is self-con­sciously Not Your Regular Problem Novel, the sort that con­cerns itself more with emo­tional iden­ti­fi­cation and val­i­dation — or, at worst, voyeurism — than with healing.)

My dis­comfort lay in the unshakeable sense that this was a therapy session, not a story.

But Green’s approach isn’t just sen­ti­mental drivel: There are no easy answers for Aza and Davis, just as there were none for the star-crossed Gus and Hazel of “The Fault in Our Stars.”

No, Aza’s anxiety is no shiny badge of indi­vid­u­ality, but her adversary: “Madness, in my admit­tedly limited expe­rience, is accom­panied by no super­powers; being men­tally unwell doesn’t make you loftily intel­ligent any more than having the flu does. So I know I should’ve been a bril­liant detective or whatever, but in actu­ality I was one of the least observant people I’d ever met.”

And her anxiety attacks force her into tighter spirals than merely unwrapping and rewrapping the bandage on her finger: Her rela­tionship with her best friend flounders because of her self-cen­teredness. Her romance with Davis dis­solves amid her night­mares about shared salival bac­teria.

Davis’s own troubles are less relatable, though they osten­sibly ground the whole (loose) plot. His father, a filthy rich man in every sense of the word, has dis­ap­peared. He has no mother; he and his younger brother may be the world’s richest orphans. The plot: Aza can help track him down. The point: Green needs to get Aza and Davis in the same room, and the stakes need to be high.

A loosely plotted adventure story is nothing new for coming-of-age novels, or for Green. (He did the same in “Looking for Alaska” and “Paper Towns.”) And neither are the troubled char­acters or the ill-fated lovers. The tear-jerker “The Fault in Our Stars” is a wildly popular story of cancer patients who fall in love and make the best of the time they have. Sweet. Probably, when the other options on the shelves include ado­lescent exper­i­men­tation (still!) with were­wolves and zombies.

A quote from Vir­ginia Woolf sum­ma­rizes Aza, Davis, and Green’s mission in “Turtles:” “The merest schoolgirl, when she falls in love, has Shake­speare or Keats to speak her mind for her; but let a suf­ferer try to describe a pain in his head to a doctor and lan­guage at once runs dry.’”

This is the quest of the “problem novel” version of the coming-of-age story: They must learn to connect through a pain that they find unspeakable, but they must also avoid destroying each other.

Green is right, and his readers likely need to learn it: Love is no therapy session. It is the way that Aza’s illness threatens to make love impos­sible that the story comes together. Her inability to connect with Davis is what finally allows her to escape the cage of her dis­order, but not in the way either of them wants, or expects.

Spoiler warning: In one of the final scenes in the novel, the two engage in a touching, mature con­ver­sation in Applebees (he tries to sit next to her; she moves to the opposite side of the booth) in which Aza comes to terms with the fact that she can’t love Davis in the way he needs. He needs physical closeness, and she needs to find a way not to drink hand san­i­tizer to stave off night­mares about bac­teria after she kisses him. She does not blame herself for her problems, but she does not deny them, either. She (or Green) phi­los­o­phizes a bit longer about the many lessons one’s first love (Aza has only had one; what does she know?) teaches, and the book ends.

The ending hits just right — too right. It is as if Green has checked every box in his list of “things that make a good coming of age novel,” and now he sits back, con­fident that he has imparted wisdom to the young folks. He has iden­tified with them and allayed their fears, and he has given them hope for health and healing and love in the future. All in the space of a 250-page novel.

Perhaps he has. Having spent some time as not only a pre­co­cious teen, but also a troubled one, I have to ask: Would “Turtles” have helped? And how — as val­i­dation, as emo­tional release, as affir­mation of the hope? And are these con­cerns primary? Isn’t the story itself, and not its emo­tional ben­efits, what matters?

Lit­er­ature can heal, but it can do a lot more while it’s at it. “Turtles All the Way Down” leaves readers on the psychiatrist’s couch.