Dramas about psychologically troubled kids seldom seem to be about the kids and are more about the adults who learn to take care of them and therefore “grow.” So it is with Darci Picoult’s Jayson With a Y, a domestic one-act whose tired formula is made tolerable by some richly realistic performances. Jayson (Miles Purinton) is a teenager suffering from an unspecified mental condition. (The press notes identify it as Asperger’s syndrome, a form of autism.) When his mother dies, Jayson falls under the care of his aunts Lynette and Kyle, who must decide whether to look after him or bundle him off to an institution. Complicating matters are Kyle’s pregnancy and Lynette’s impending move to France. Each aunt eventually betrays Jayson and then atones for her transgressions in awkward, sometimes hedged apologies. Clearly the adults are just as emotionally unreliable as Jayson, a point that the play takes eons to illustrate. As Lynette, the excellent Maryann Plunkett colors in her ambiguous character with a vibrant set of physical details. As Jayson, Purinton does the most he can in a role that would have worked better as an offstage presence. The scenes between Jayson and Lynette are by far the play’s best. These two unpredictable characters (and the talented actors who play them) definitely deserve each other.