"I was in my final year of Toi Whakaari drama school, which is a challenging environment anyway. I was trying to be happy and quiet, and positive and energetic for everyone else.
"I wanted to strive, to prove that I could reach the pinnacle of everything, but in doing so I was quite hard on myself."
Pohatu's struggle reached a crisis point while he was staying on a farm in Nuhaka, near Gisborne, for a school secondment.
"Everyone in my class went off and did something different and then the idea was to bring all our experiences into the end-of-year show.
"I ended up having a nervous breakdown in front of the guy I was staying with.
"It took a while for me to register what had happened."
Pohatu left Toi Whakaari and stayed with his mother in Marton for four months.
"I was diagnosed with bipolar disorder. The turning point for me was when I allowed myself to be ill, then I was able to start healing.
"I was lucky to have a huge amount of support from mum and the rest of my family and friends.
"Part of my healing was learning to be kind to myself. I realised I would never be as negative to my family and friends as I was to myself."
Pohatu moved back to Wellington and redid his final year of drama school. He did an assignment on the connection between mental illness and actors, and spoke about his experiences to his class.
"Depression can affect anyone but it is quite common among creatives.
"In order to create, you've got to put a lot of senses into your work and draw from a lot of places.
"Then there's also stress over finances because work is not always guaranteed, and there's a level of criticism no matter your work."
Since drama school, Pohatu has performed in multiple stage and TV productions, been in his first feature film - Robert Sarkies' black comedy Two Little Boys - and had global success with his showband-style group, the Modern Maori Quartet.
He no longer receives counselling or takes medication, but still checks in with doctors, and is wary of the occasional high as well as low.
He took his mum to last week's well-received premiere of what he describes as the "beautiful and very nostalgic", Poi E film.
Where to go for help
Lifeline 0800 543 354
\Depression Helpline (24 x 7) 0800 111 757
Healthline 0800 611 116