If Pixar films have taught us one thing, it’s that everything we love will one day come to an end. We will forget our childhood toys. Our loved ones will die and leave us alone in the world. Eventually, we all have to grow up.

Inside Out, the studio’s fifteenth feature film, looks its audience square in the eye and flat out tells them “You will not always be happy. Sometimes, you will be unbearably sad. And that’s OK.” Few animated films would dare to deliver such a frank message. Fewer still could do it with this level of artistry and grace.

Pixar has made artists out of vermin and heroes out of insects. They’ve transported us to the bottom of the ocean and the furthest corners of the universe. Yet that all pales in comparison to the boundless creativity present in the world of Inside Out – a feat that’s only more impressive considering that world fits inside the head of an 11 year-old girl.

Mom's Emotions

Courtesy of: Walt Disney Studios Motion Pictures

From the movie studio backlot where (literal) dreams are made to the labyrinthine shelves of Long Term Memory and the sleek, Star Trek-inspired Headquarters, Riley Andersen’s head is unlike anything else in Pixar’s history. But deep down it feels strangely plausible, perhaps because of how acutely director Pete Docter seems to understand the human condition. After all, of us has our own core memories, the foundations of the islands of our personality – be they our families, our friends or our interests.

In two stand-out sequences we see into the minds of other characters (including animals); worlds that will never meet but have a profound impact on each other. It’s a wonderful concept, but a bittersweet one too. While Riley’s life has been governed by Joy, her mother and father are led by Sadness and Anger respectively. We can’t help but wonder which emotion is holding our own mental steering wheel.

Some asked whether giving the protagonist five emotions – Joy, Sadness, Anger, Fear and Disgust – was too simplistic, but in action they prove a perfect balance. Look at how Riley becomes a stereotypically moody teenager when deprived of her two chief emotions – what is sarcasm, after all, but Disgust masquerading as Joy?

Anger

Courtey of: Walt Disney Studios Motion Pictures

It helps that, rather than simply being one-note caricatures, the emotions feel as human as anyone in the outside world. Mindy Kaling, Bill Hader and Lewis Black all provide wonderfully different flavours of (frankly much-needed) comic relief, but the real depth is in the rivalry between Joy and Sadness.

Amy Poehler proves an inspired match for the former, her permanently chipper attitude dancing on a knife-edge between optimistic and annoying. Much like Woody in the original Toy Story, she ultimately proves to be her own worst enemy – a well-meaning control freak driven to extreme measures by a rival she just doesn’t understand. But it’s through Sadness, played by a note perfect Phyllis Smith, that the film transcends even Pixar’s lofty heights to deliver an essential sermon about mental health. Watching the control desk in Riley’s mind go dark, the emotions unable to elicit the tiniest feeling in the young girl, is one of the most effective (and frightening) analogies for depression ever committed to film; one that will strike a chord with many people struggling to deal with its effect on their everyday existence.

Pixar movies have always been able to reduce the stoniest of souls to tears, and Inside Out is no exception. Watching Riley’s forgotten imaginary friend Bing Bong sacrifice himself to save Joy is like the furnace scene in Toy Story 3 multiplied by the opening montage in Up, and Richard Kind’s final line – “Take her to the moon for me, OK?” – hits harder than a thousand Cate Blanchetts saying “I love you”. But even more devastating than that is the moment when a little girl finally breaks down and cries in front of her parents. “You need me to be happy,” she tells them, “but I want to go home. Please don’t be mad.”

Joy

Courtesy of: Walt Disney Studios Motion Pictures

Throughout the film Riley has been referred to as “our happy girl”, and “our bundle of joy”, the one who can be relied on to keep her parents happy during a turbulent phase in their lives. But in taking on this role, she – like so many depression sufferers who are simply told to “get over it” – is denied the chance to express herself emotionally.

In a year that’s seen women rule the wasteland and the galaxy far, far away get a much-needed diversity boost, the idea that sadness is not only normal but essential for a healthy mind might not seem like the most revolutionary moral. But it’s one that people desperately need to hear, and it’s that kind of storytelling that makes Pixar one of the greatest film studios of all time.