“This is not the soul I want,” says poet Alex Macfarlane, by way of explanation – or apology? – for the verbal self-immolation unfolding on stage. Demanding, disturbing but never self-pitying, Reflections Upon An Ugly Little Soul documents Macfarlane’s real-life encounters with mental ill-health; or as he puts it, “a whistlestop tour around the flawed parts of my brain”. It’s a challenging concept, but the seed for a sensitive and surprisingly inspiring show.

The ugliness is illusory, but the reflections are real. The stage is ringed with full-length mirrors – turning it into an arena of introspection, where Macfarlane addresses his poems directly to his own image. We see ourselves in the mirrors too, or sometimes they offer us a voyeuristic glimpse of the emotions on Macfarlane’s face while his back is turned. It’s a brilliantly simple yet supremely eloquent concept, perfectly capturing the sense of tortured yet inescapable self-analysis.

The poems are dark and, occasionally, hard to listen to. One is about how Macfarlane hates his own hands, expanding quickly to everything else about him. One is a fantasy of suicide, of a kind. He swings in a moment from towering arrogance to abyssal self-loathing. Yet there’s hope here too, in a supportive letter he writes to himself, or in the remembered joy of the simple act of giving a dog a biscuit.

Between the poems Macfarlane retreats out of the circle of mirrors, taking brief respite from the intensity of self-inspection to comment on the words we’ve just heard. The artifice of these asides landed a little heavily on me – particularly the way they frame as spontaneous lines that are, very clearly, carefully planned. But there are some intriguing ideas to be found there too, including a deconstruction of the slippery nature of contemporary poetry and, alarmingly for me, a compendium of the faint praise reviewers are known to dispense.

There’s no need for weasel words here though: Macfarlane’s poetry is clever and compelling, just aware enough of its own self-absorption and raw enough to hold us enthralled. It’s a dynamic physical performance too, as Macfarlane angrily stares down his own reflection and spins from mirror to mirror across the stage. At the end, he says his goal for the show is to assure other people their experience is valid. I hope that, in a different but important way, performing it has validated his experience too.