"Only When I Laugh," a bleary tear-jerker about the relapse of a Broadway lush, is shallow and dispiriting enough to drive you to drink. A revamp of Neil Simon's theatrical contrivance "The Gingerbread Lady," "Laugh" is orchestrated to highlight predictable displays of chipperness and wrenching vulnerability. Marsha Mason (the author's missus) inherits the role originated by Maureen Stapleton, presumably nailing down her customary Oscar nomination with every resilient smile and chin-collapsing sob.

"Laugh" formulates a dubious case for the downfall and rehabilitation of Georgia Hines, a Broadway actress attempting to resume her career and renew acquaintance with her solicitous, upstanding teen-age kid Polly, a lackluster subordinate role for the exceptionally talented Kristy McNichol. The heroine is introduced with incisive effectiveness -- a tactic somehow mislaid by Simon and director Glenn Jordan as the script stumbles along. We first encounter Georgia as a disembodied voice, evaluating her progress while speaking from the darkened office of her physician. After shedding 30 pounds and a lust for vodka at a private sanitarium on Long Island, she hopes to pick up the pieces of a life evidently left in tatters 12 weeks earlier in Manhattan.

She's welcomed back with steadfast devotion by cronies Toby (Joan Hackett), a wealthy fashion plate alarmed at the approach of her 40th birthday, and Jimmy (James Coco), an unemployed, jocular, tiresomely dear homosexual actor. Typical in-group snapper: Jimmy takes a look at the old dress hanging from Georgia's streamlined contours and exclaims, "We've gotta get her some new clothes! She looks like she's wearing the drapes from Radio City Music Hall!"

Polly, who has been living with her dad and his second wife, off-screen characters, announces her intention to move in with Georgia, who protests that she may not be ready to handle the responsibility but relents after a bit of coaxing. In fact, the prospects for Georgia's recovery look pretty rosy. Everybody close to her demonstrably cares. Indeed, when she threatens to hit the skids again, her nearest and dearest reaffirm their devotion. Sample reassurances: "I'm a friend because I love you, and I am in awe of your gifts" and "You're loved because you're special; special people deserve to be loved." Has Simon ever thought of marketing a line of get-well cards?

If anything, it's difficult to see precisely what reduced Georgia to drunken humiliation in the first place. The explanation supposedly enters in the person of David Dukes, cast as a vaguely sinister playwright, also named David, whose romantic conflicts with Georgia somehow provoked her breakdown.

One gathers they were bad for each other: Georgia degenerated into a flabby, shrewish dipso while David suffered writer's block. Despite this unhappy association, David urges Georgia to read his new manuscript, a play based on their own punishing affair, and she's wowed by it. Unable to resist such a juicy role, Georgia agrees to make her comeback playing her erstwhile wretched self.

Simon, preoccupied with putting interchangeable wisecracks in the mouths of his characters, overlooks the scrumptious opportunity for satire implicit in Georgia's choice of a comeback vehicle. He inserts only a brief, tantalizing moment from this presumably howling psychodrama. He never advances the plot as far as opening night, which surely looms as a night to savor.

Georgia evidently retains fond hopes of a romantic reunion with David. She acts inexplicably devastated when he introduces her to his new fiance' one morning before rehearsal. Going into a despondent tailspin, Georgia flirts with a fresh breakdown. She scandalizes Polly and her date at Toby's birthday party, already blighted by Toby's bad news -- her husband, another off-screen character, has walked out. Donning cloak and slouch hat, Georgia stalks the streets like Mr. Hyde and invites trouble at a bar, cozying up to a guy who later reacts viciously when she tries to fend off his sexual advances.

Battered and degraded the next morning, Georgia proves susceptible to the loving scolding administered by Jimmy, Toby and Polly. As the story conks out, we're led to believe that this heartbreak gal has found the courage to pull herself together again.

One might rationalize the skimpiness of the motivation by arguing that show people can't help being shameless. Simon's writing tends to confirm the proposition, and the most evocative aspect of Mason's performance is probably her increasing facial resemblance to Judy Garland rather than any specific character flaw attributed to Georgia.

However, the movie's popularity may depend upon spectators, women in particular, filling out Georgia's inadequately documented case history with a private inventory of regrets and apprehensions.

While more respectable artistically, a better script would have provided less incentive for mawkish reverie. Like the ineffable "Love Story," Simon's acidic heart-warmer needs an audience slightly desperate to get all choked up.