The Effect review – Lucy Prebble’s intense and intoxicating encounter

Senses are sharpened in Jamie Lloyd’s slick, heady revival of Lucy Prebble’s 2012 play. If the script seems somewhat sober compared with the writer’s recent TV heights of I Hate Suzie and Succession, it remains an intellectually and physically intense experience, with subtle edits that sharpen and freshen the text for a stellar new cast. With heightened attention paid to breath, nerves and touch, The Effect ceaselessly questions which parts of our brains and bodies we can rely on and control.

Related: ‘Succession was like coming home’: Lucy Prebble on life inside TV’s greatest show

In a drug trial for a new antidepressant, Tristan (Paapa Essiedu) and Connie (Taylor Russell, in her stage debut) fall in love, but the haze of the trial’s side effects make it impossible to tell how far their attraction is real. Essiedu and Russell are gorgeous together; she holds herself with a controlled stillness, a quiet confidence in her curiosity, while he is looser, bounding around, joking and flirting and quick to fly into fury. Within the claustrophobic space, they gravitate together, the glow of their faces as they lean into each other flooding the clinical stage with warmth.

Lloyd’s elegant direction does away with props and set pieces, allowing the actors to glide across Jon Clark’s bright white LED floor that robs them of their shadows, creating a dazzling sense of unreality. Soon into the trial, Connie reports an increased level of hearing, a feeling George Dennis’s sound design and Michael Asante’s composition accentuate; the audio feels closer, almost tangible. The thudding, ticking score wracks up the intensity as their distrust of their feelings increase.

On either side of the traverse stage sit Dr Lorna James (Michele Austin, utterly captivating), the experiment’s psychologist, and Dr Toby Sealey (Kobna Holdbrook-Smith, his voice like velvet), the boss who needs the trial to work. They watch each other – almost more than they watch their patients – as trust, bias and any semblance of control fall to pieces. With cynicism about how far the artificial medical environment can truly reflect the complexities of real life and a laser-sharp focus on the fallibilities of our bodies, The Effect evokes the deliciously unsettling feeling that all of us are nothing more than bundles of chemicals in ongoing experiments. These two just happen to be the ones being examined.

• At the Lyttelton theatre, National Theatre, London, until 7 October