"Canvas," Joseph Greco’s drama about schizophrenia, is obviously a labor of love. In his director’s note Mr. Greco writes, “I grew up watching my mother battle schizophrenia, and those harrowing memories had a profound impact on me.” He adds that a screenwriting professor once told him, “Write what you know.” That advice has resulted in a movie that rings emotionally true, despite structural contrivances and dim, washed-out color.

Because Mary Marino, the afflicted mother, is portrayed by the gifted Marcia Gay Harden, “Canvas” never threatens to become the kind of quasi-horror film that movies about the mentally ill tend to be. Cast in a role that would tempt many actresses to indulge in award-seeking histrionics, Ms. Harden underplays Mary’s recurrent symptoms until the last moment. When the voices that periodically torment her return, her ears prick up, and her eyes dart, as expectancy mingles with fear that rapidly escalates to panic. Even when she erupts, you sense the human being in pain huddled inside the uncontrollably raving creature.

The story begins as Chris (Devon Gearhart), the 10-year-old son of Mary and her husband, John (Joe Pantoliano), returns to his family’s home in Hollywood, Fla. Chris had been staying with relatives while his mother was hospitalized, and almost immediately it becomes clear that her mental stability is hanging by a thread. As she becomes delusional, then paranoid, you share her husband’s sinking feeling that it’s always going to be this way and his frustration at finding that his love is powerless against demons with whom there is no reasoning.

Mr. Pantoliano’s John emerges as a working-class saint who, through some combination of devotion and inner resilience, almost never rises to the bait when Mary becomes shrill and irrational. But even he has his limits. Chris, being younger, isn’t so patient. When his mother embarrasses him in front of his peers, he half blames her and wants to escape. In her more lucid moments Mary is mortified by her behavior.

The Marinos are devastated in countless ways. Mary’s hospital bills drive John, who works in construction, into debt. The movie gives only a taste of the stress he undergoes dealing with insurance companies. His patience is tested when Mary, like so many schizophrenics, refuses to take her medication. Chris has nightmares that reflect his fear of having inherited his mother’s illness.

When the police are called to the house one too many times, the neighbors’ tolerance evaporates. How does life go on? Well, somehow it does.

The movie’s title refers both to Mary’s therapeutic painting, which, she explains, quiets the voices inside her head, and to John’s construction of a sailboat in the backyard as a present for her. Chris also develops a profitable sideline sewing custom-made patched shirts for his classmates and experiences puppy love for the first time.

If “Canvas” tries much too hard to soften the Marinos’ anguish by emphasizing the father and son’s creativity and resilience, a tougher, more realistic movie would probably be close to unbearably painful. Below the film’s sugar coating is an inner core of integrity and goodness. All three Marinos are noble everyday people visited by horror. Think of “Canvas” as a Lifetime movie: a likable one.

“Canvas” is rated PG-13 (Parents strongly cautioned) for mature thematic elements.

CANVAS

Written and directed by Joseph Greco; director of photography, Rob Sweeney; edited by Nina Kawasaki; music by Joel Goodman; production designer, Bill Cimino; produced by Sharon Lane, Adam Hammel, Lucy Hammel, Joe Pantoliano, and Bill Erfurth. Running time: 101 minutes.

WITH: Joe Pantoliano (John Marino), Marcia Gay Harden (Mary Marino), Devon Gearhart (Chris Marino), Paul Lasa (Hector), Marcus Johns (Sam) and Sophia Bairley (Dawn).