Mental disabilities have periodically been the subject of successful Hollywood films.

Generally speaking, they divide themselves into two almost opposite categories.

The first transforms the afflicted into a noble innocent whose inherent sweetness is often misunderstood (Charly and Rain Man). These movies tend to be sentimental and, often, to glorify victimhood. Their success is measured by how often the audience cries.

The second type emphasizes the out-of-control, even violent aspects of the condition (Primal Fear, Sybil and The Three Faces of Eve). The behavior depicted is exotic and outrageous. The intention is to scare viewers, almost as if they were watching a horror film. Sometimes a movie like the 1999 hit Girl, Interrupted attempts to combine both types.

Two recent releases — I Am Sam and A Beautiful Mind — self-consciously try to pump new life into these genres. Sam uses flashy visuals and a hip soundtrack to mask its conformity to most of the clichés of the noble-innocent category. Mind intelligently reverses our understanding of the out-of-control madman stereotype, but not before including some well-calculated tugs at our heartstrings of its own.

I Am Sam is an old-fashioned weepie disguised as an issue film about child custody. The lead character of the title, played by Sean Penn, is a decent, hard-working laborer with the mental and emotional age of a 7-year-old. He's trying to raise his daughter, Lucy (Dakota Fanning), on his own. As she approaches 8, she begins to grow beyond Sam in reading and social skills.

After Sam gets in trouble with the law, the state tries to take his daughter away from him. This sets up an emotional scene that director Jessie Nelson and co-screenwriter Kristin Johnson repeat in different forms throughout: A sobbing daughter is wrenched away from her loving dad. They milk it shamelessly.

In order to get Lucy back, Sam retains a high-powered attorney, Rita (Michelle Pfeiffer), who's guilt-tripped into taking the case pro bono. She has her own child whom she neglects and a resentful husband whom we never see.

There are real issues to be explored in Rita's situation, but the filmmakers make all the predictable dramatic choices. It's obvious after her very first scene with Sam what her arc will be. Involvement with this case is going to humanize her so that she will pay more attention to her kid and less to her career ambitions.

The key question, however, is whether Sam has the capabilities to raise a child whose mental powers are more advanced than his. The filmmakers fudge the answers whenever they can, preferring to underline how much Sam, Lucy and Rita are suffering personally.

The movie's message seems to be an uncritical repetition of the Beatles’ song “All You Need is Love,” which is covered on the soundtrack along with a half-dozen other LennonMcCartney classics. The music seems to have inspired an MTV style of visual tricks, with zooms and quick pans to distract the audience from thinking too deeply. But those who like to shed tears in a movie theater will get their money's worth.

A Beautiful Mind is smarter about its material. Like the 1996 hit Shine, it chronicles the descent of a great talent into madness. But Mind, freely adapted from Sylvia Nasar's prizewinning biography of mathematician John Nash, takes a more sophisticated view of mental illness. Director Ron Howard (Apollo 13) and screenwriter Akiva Goldman get the audience inside Nash's head and make us see the world as Nash does, imaginatively finding visual equivalents for his interior, mental state.

Both films make a plea on behalf of the mentally challenged.

The action begins in 1947 when the young Nash (Russell Crowe) enters Princeton as a graduate student. The filmmakers capture the sense of intellectual ferment pulsing through that elite academic community and make us believe Nash really is a genius. A social misfit, he produces a groundbreaking doctoral dissertation on game-theory economics that will win the Nobel Prize 47 years later.

Nash lands a plum job at an MIT defense-research lab. While doing this paranoia-inducing, highly classified work, he develops a form of schizophrenia that gradually takes over his mind until he can longer separate his hallucinations from reality. After a complete breakdown, he's institutionalized and subjected to insulin shock treatments.

Upon his release, he is prescribed drugs that numb his senses. Nash attempts to “solve” his illness like a math equation, through logic and discipline, without the use of medications. The result is a series of setbacks.

The filmmakers never present Nash as a victim. His courage in fighting his way back to some kind of sanity is awe-inspiring. Unlike previous Hollywood treatments of the subject, schizophrenia is depicted as an illness that can be managed.

In a slight improvement on the facts, Nash's wife, Alicia (Jennifer Connelly) is shown standing by her man through thick and thin. Some have criticized this and other liberties that filmmakers have taken, particularly in regard to the darker side of his personal life. But the movie pointedly presents itself as “based on” Nash's life rather a literal recitation of events. The changes made seem justified by the larger dramatic truth that the movie wants to communicate about the nature of schizophrenia.

Both I Am Sam and A Beautiful Mind have admirable intentions. Each makes a sincere plea for greater tolerance of those with mental problems. Sam doesn't tell us anything we don't already know. Mind expands the boundaries of popular knowledge on the subject.

John Prizer writes from Los Angeles.