The second part of the title of Camilla Whitehill’s Channel 4 comedy drama is a reference to mood disorders. Bipolar, to be exact – the condition her protagonist Maggie has been diagnosed with. The first part is a reference to pretty much everything else. Big Mood tackles big topics and chases big laughs. There are big adventures, big gestures and big cameos. It’s undeniably ambitious, but does all this add up to something truly meaningful? It can be difficult to tell.

Series one introduced Maggie in the midst of a manic episode: she had pestered her alma mater to let her deliver a speech in the hope of seducing her old history teacher. That quickly gave way to a depressive one, during which she attended her 30th birthday party unshowered and on the verge of tears. The reason for this rollercoaster was Maggie’s decision to stop taking her medication; she believed it was impeding her creative capabilities and her career as a playwright. Eventually, she agreed to go back on lithium, only to experience terrifying hallucinations and confusion – she’d been poisoned by an erroneous prescription filled out by an overwhelmed psychiatrist.

As a portrayal of bipolar, Big Mood was hugely insightful and nuanced; Maggie’s inner hell was externalised flawlessly by Bridgerton and Derry Girls star Nicola Coughlan. Yet it was immediately clear that the show’s interests were divided. It wanted to be realistic and heartfelt, but also thigh-slappingly hilarious. It’s always heartening to see art that’s alive to the absurdity of mental illness without minimising it, but I have to admit Big Mood’s combination of wacky sitcom contrivances, self-conscious quirk and tasteless Fleabagian humour left me cold.

Then there was Big Mood’s other major preoccupation: the bond between Maggie and her best pal Eddie (It’s a Sin’s Lydia West). The intensity of the pair’s dynamic seemed a tad unrealistic considering their age, although it did ask compelling questions about the nature of friendship. Eddie was becoming resentful of the unbalanced nature of their support system, and when she finally had some serious problems of her own, she felt her best friend had deserted her. Maggie had a legitimate excuse: she was experiencing bouts of unconsciousness and being taunted by imaginary demonic kids. But Eddie didn’t know that, and fled east London for California without so much as a goodbye.

Now Big Mood is back – or at least Maggie is. Having recovered from the lithium poisoning, she is now in her “stable girl era”; a retinol and Hello Fresh user with a six-stage morning routine codified in her notes app. Yet she’s still pining after Eddie, who has been incommunicado for the past year. The wedding of a mutual friend teases the possibility of reconciliation, and as Maggie waits for her erstwhile bestie to arrive she’s distracted by a ludicrously militant maid of honour, a Florence Nightingale-inspired bridesmaid dress and the hunt for the bride’s secret husband who has arrived to extort the happy couple. But once these minor japes have concluded, the major intrigue begins: Eddie has returned under the thumb of a wellness guru called Whitney, who has already taken all her money and now wants to obliterate the last remnants of Eddie and Maggie’s relationship.

In other words, Big Mood is no longer about mood disorders. Maggie stays on a relatively even keel despite a distressing encounter with her estranged dad, an iconic Mancunian comedian and total arsehole (a very convincing Robert Lindsay). Instead, we get knockabout farce layered on top of a painstaking dissection of Eddie and Maggie’s series one rift. In an effort to reconcile, Maggie becomes fixated on proving that Whitney is a scammer, even teaming up with Eddie’s friend Will – an incorrigible nice guy who both women treat with utter contempt in a way that is genuinely upsetting – to comprehensively rumble her.

It’s not an easy storyline to invest in. As a character, Eddie originally seemed smart, cynical and allergic to bullshit: her falling for Whitney’s grift doesn’t really track. And despite Coughlan’s empathetic performance, Maggie is still destructive enough to justify Eddie’s initial decision to cut ties.

Of course, humour is subjective and so is charm: if you’re liable to get swept up in the messy millennial-ness of it all, these will seem like quibbles. And it’s true that the broad-strokes comedy does occasionally give way to substantial dramatic insight. But while Eddie and Maggie’s platonic romance may have been intoxicating in their youth, now it just seems toxic. Perhaps it’s time for everyone involved in this dysfunctional friendship to move on.