Amy Sillman’s new work will force her admirers to rethink a painter they thought they knew.

Once a personalist whose work often took a diaristic form, Ms. Sillman was known for portraying complex, intersecting narratives within a painting. She didn’t put forward a painterly mark as a seismograph of authentic, inner feeling so much as deploy a variety of language at the service of personal narrative. Now she has almost converted to full-blown expressionism. It is as if someone has turned up the volume.

The beefy, vigorous, strident paintings at Sikkema Jenkins, delivered with an assured hand, have appropriately solid titles that reflect Ms. Sillman’s determination to stand her ground: “The Elephant in the Room,” “Big Girl,” “Plumbing” (all paintings 2006). She has retained her characteristic busyness of surface, and there are still instances of tentative mark-making, loose edges, and ambiguous spaces. But the energy is now empathically centered.

Her mousy, somewhat cramped handwriting is increasingly giving way to spirited flourishes, an assured bravura. The dark-green, vessel-like form in “A Bird in the Hand,” for instance, is defined volumetrically in a whiplash line.

With this change in technique comes a decisive shift in attitude toward style itself. Before, there was more than a whiff of postmodernism in Ms. Sillman’s sly referencing of postwar salon abstraction; now her work denies irony, placing full-blown earnestness in its place. It is as if she painted out the quotation marks.

Why are the bolstered qualities in Ms. Sillman – invigorated focus, sumptuous scale, confident brushwork – unsettling? After all, these are the signs of painterly upward mobility, what everyone should strive for. But much of what defined Ms. Sillman had to do with her deep-seated anxieties about painterly language. Resolution threatens to remove the ambiguities and idiosyncrasies that used to be her hallmarks.

Yet Ms. Sillman has retained a wholesome quotient of quirkiness. “Your Puppet” has a goofy cartoonery that recalls Philip Guston, her familiar avatar, along with his penchant for grays and pinks and an agitated, brushy scribble. A succulent impasto differentiates the fleshed-out figures from the stick-figure mannequin of the title.

“Plumbing” has a density and depth that defy easy decoding; though the left hand of the composition is spare and orderly, the right is a mess. A spindly figure whose caricature-like extended right arm sports a sack leaves behind an open door filled with a deep, messy scramble of lines and marks. Perhaps this is the plumbing of the title, and also the contingent, personal mess of the artist’s past – whether personal or stylistic – buried in the closet but always ready to come tumbling out.

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Jack Pierson and Billy Sullivan both qualify as personalists. Each in his way makes fey art touched with the dissipated feeling of the end of a party, a hopeless infatuation, a sensation of lost time. Borrowing the rococo handwriting of fashion illustration, each mixes elegy and indulgence by cultivating a tender, knowingly flimsy hand.

Mr. Pierson’s new show at Cheim & Read takes its title, “Melancholia Passing Into Madness,” from a 19th-century photograph of a deranged woman at the moment neurosis turns to psychosis. As “Melancholia,” the farewell exhibition of French curator Jean Clair currently at Berlin’s Nationalgalerie, makes clear, art’s fascination with the bleak state of mind is long-running and intimately tied up with Romantic notions that link creativity and imbalance. From Durer to Mr. Pierson via Charcot, it is a state best personified in the female form.

This show encompasses disparate mediums in an elegantly sustained meditation on the melancholic mood. Included are three of his trademark word sculptures (his best work, to my mind) made from different found letters cannibalized from antique commercial signs. The words or phrases on offer are “Roses Roses Roses,” “Another Night,” and “Melancholia”- the latter zigzagging down the wall before dropping to the floor.

Also here is a series of pages from women authors as various as Joan Didion, Carson McCullers, Marilyn Monroe, and Sister Wendy Beckett, each transcribed by hand in emulation of the printed page, set on a large galley-like sheet of white paper. video made with Ursula Hodel is a somewhat puerile affair with a dominatrix recounting her past life as an Egyptian queen; with its tacky, amateur quality, it is blown up to an unsustainable size in the gallery’s project space. And then there is a montage of vintage studio portraits of handsome young actors.

The main event, however, consists of eight 6 1 /2-foot-high screen printed canvases derived from the artist’s drawings after the photograph of the show’s title. The sequence presumably envisages the gradual devolution of the afflicted woman’s spirits, but the artist’s goofy, primitive hand doesn’t convey any specific mood with accuracy or insight. In fact, these could be portraits of a person of either gender, feeling any mood. But the cool, Warholian remoteness of blown-up silk screen combined with the scribbled urgency of Mr. Pierson’s line results in an odd fusion of presentness and remoteness that conveys alienation, if not melancholy.

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The ambivalent title of Mr. Sullivan’s show speaks to his project: “Friends” could equally designate the relationship of the sitters to each other, or to the artist. A similar tension between intimacy and distance affects the personalities depicted and the character of their depiction. We are left to wonder whether the artist is emotionally invested in his technique, or whether it is knowingly secondhand.

Hot color and compressed space suggest Mr. Sullivan has looked longingly at Matisse, but the odd mix of labor and rush in his work is diametrically opposed to the master’s. The amateurism of his cramped delivery is energizing if you sympathize with his project, enervating if you don’t – either way, it is so overt it must be intentional.

Many of the paintings use images familiar from the retrospective overview of Mr. Sullivan’s photographs, projected by slide carousel to three walls simultaneously to form an installation within the current Whitney Biennial. As a painter, he looks a lot like Elisabeth Peyton (they both look to David Hockney), and as a photographer there are strong moments of Nan Goldin, one of his subjects. But Mr. Sullivan doesn’t have the inner resonance of either female peer, that poignant tension they each achieve between Old Master grandeur and the ephemeral nature of a mediated life.

Sillman until May 6 (530 W. 22nd Street, between Tenth and Eleventh Avenues, 212-929-2262). Prices: $25,000-$50,000. Pierson until May 6 (547 W. 25th Street, between Tenth and Eleventh Avenues, 212-242-7727). Prices: $10,000- $200,000.Sullivan until May 6 (526 W. 26th Street, between Tenth and Eleventh Avenues, 212-243-3335). Prices: $20,000- $40,000.