Two very long hours: The Effect, at the Lyttelton Theatre, reviewed

Lucy Prebble belongs to the posse of scribblers responsible for the HBO hit, Succession. Perhaps in honour of this distinction, her 2012 play, The Effect, has been revived at the National by master-director Jamie Lloyd. The show is a sitcom set in Britain’s most dysfunctional drug-testing facility where two sexy young volunteers, Tristan and Connie, are fed an experimental love potion that may help medics to find a cure for narcissists suffering from depression. Running the experiment are two weird boffins, Professor Brainstorm and Nurse Snooty, who once enjoyed a fling at a conference and whose lust is not entirely extinct. But Nurse Snooty is playing hard to get. ‘Sometimes,’ she tells the Professor, ‘I feel I’m dead but my body hasn’t caught up yet.’ The Professor, a psychiatrist by trade, fails to spot the negative signals here and continues to bombard her with lecherous suggestions.

Meanwhile, in the mixed-sex ward, Tristan and Connie are flirting like mad even though they have nothing in common. She’s a feminist psychology student who likes older professional academics. He’s a penniless half-wit from east London who makes a living by volunteering for medical trials. Yet Connie seems mysteriously smitten with this talentless creep even though he mocks her accent and mannerisms. And she encourages his mistreatment by tittering uncontrollably at his jibes.

To explain her nervous giggles she spouts antique psychological platitudes. ‘Female laughter is a show of submission,’ she says. Since the two lovebirds have swallowed a medical aphrodisiac, their flirtation owes more to pharmacology than to desire and this makes the romance feel contrived and half-cooked.

One night, they break out of the facility and climb the roof of a nearby mental asylum where they continue to flirt by practising ballet twirls and break-dancing.