Serenading Louie, Donmar Warehouse

American spiritual anomie, that beloved realm of cultural enquiry that has fuelled the likes of Revolutionary Road and Ordinary People and much else besides, gets its latest theatrical airing in the form of Serenading Louie, a Lanford Wilson play that is almost as infrequently seen States-side as it is here. Now, here it is at the Donmar, in a mournful, acutely pitched production from the director Simon Curtis (Cranford) that doesn't shrink from confronting head on the abyss into which the characters are falling fast. Hang on for what is a flawed but, if you stick with it, mesmerising ride, featuring several of the finest performances currently to be found on a London stage.

In a sense, the play makes a provocative, if unwitting, companion piece to the incoming revival of Hair, a celebration of the '60s counter-culture that feeds directly into the collective psychic hangover, ca. 1970, which is where Wilson's little-known play begins. (The title, by the way, comes from Yale's "Whiffenpoofs Song," an American university favourite whose lyrics also include a line, tellingly quoted in the first act, about being "doomed from here to eternity".)

The two couples who share Peter McKintosh's deliberately (and scarily) faceless set are both presumably aspirational and, on first appearance anyway, civil. Alex (the excellent Jason Butler Harner, the cast's lone American import) and his wife, Gabby (Charlotte Emmerson, struggling with her accent on the word "over"), go to the movies and seem to function well in public; it's only once they get home that their defenses drop and that the wiry Alex can talk of "being raped every night" by his sexually starved wife. His response to the lowering domestic temperature is to retreat to a telephone in the living room, from which he can call a 17-year-old called Debbie.

Alex's university chums, Carl (Jason O'Mara, resembling a hunkier Michael Ball) and Mary (Geraldine Somerville, in a spectacularly smart performance), are on first sighting prettier - both actors look positively golden - and less careworn, but don't be deceived. The business-minded, heavy-drinking Carl is clinging with increasing degrees of panic to his erstwhile status as a local football legend (at one point, he is compared to Paul Bunyan), while the comely Mary is having an affair with Carl's accountant in between announcing, in reaction to the social activism of the age, "I do nothing." Her tolerance level dwindling by the day for a society in flux, she's like a slightly more grown-up Honey, from Who's Afraid of Virginia Woolf?, a play in which O'Mara, incidentally, would make a top-flight Nick.

Curtis, the director, pays particularly commendable heed to the subtle indices in the text of the world beyond the inky blackness that hovers tellingly at the rear of the stage. Alex, a lawyer, speaks of upping sticks, shifting his career, and moving to Washington, which is gradually seen to be a none-too-welcoming option, as one might expect from a play written in the immediate aftermath of Watergate. And though talk of hippies and demos seeps through, such concerns are always folded into Wilson's anatomy of an uneasy middle-class that is seen to be paying a wounding price for so much change so fast. Or as Alex remarks to his wife, "Honey, don't expect."

That might well be the best advice for playgoers anticipating from Serenading Louie the white heat given off by such recent American entries at the Donmar as the revival of A Streetcar Named Desire and the utterly galvanic, now Broadway-bound Red. Talkier than both those plays and possessed of a bleakness of near-relentless severity, this is best regarded as a bitingly presented curiosity from a defining American dramatist who these days doesn't get enough of an airing either side of the Atlantic. (The last major London production of one of his shows was Burn This with John Malkovich, over 20 years ago, while the last New York production of Serenading Louie was Off Broadway in 1984.)

I agree with the common criticism lobbed its direction that the ending falls into melodrama, whereas a more genuinely bruising finish to this play might show what happens in life when you don't take the most dramatically decisive option. But I wouldn't want to miss Curtis's return to theatrical terrain he has trawled before via both A Lie of the Mind and Dinner With Friends and I certainly wouldn't forego this cast. "Nothing's an event any more," muses Carl early on, as a slow-simmering O'Mara sits on a gathering anger that is waiting to go snap. But he's wrong: acting this fine is a real occasion.

Serenading Louie is at the Donmar Warehouse until 27 March before a three-week tour.