A sombre, intense psychological drama, David Cronenberg's "Spider" takes the viewer on a slow crawl through the mind of a schizophrenic. A date movie, it isn't.

Ralph Fiennes is the title character, a subdued, mentally disturbed individual placed in a halfway house in the east end of London after years confined to an asylum.

Under the tutelage of Lynn Redgrave's harridan, he must try and re-enter a society that appears cold, empty and alien to him, while revisiting his childhood haunts and replaying memories of his troubled youth.

These 'flashbacks' constitute the bulk of the film, with Spider standing within his recollections, looking on as his young self (Bradley Hall) witnesses his parents' marriage crumble.

The fact that his mother and the other woman his father (Gabriel Byrne) shacks up with are both played by Miranda Richardson points to the head-messing nature of Spider's condition.

Clearly, something is Not Quite Right.

The problem with the underplayed mystery/thriller element of "Spider" is that this 'something' is pretty obvious from the start.

Without any compelling narrative hook, the movie's value is in exploring the psyche of the muttering, tramp-like unfortunates whom people try and avoid in parks.

Screenwriter Patrick McGrath, who adapted his own novel, has worked in mental health care, and his script certainly provides a more measured, truthful approach to schizophrenia than Ron Howard's feelgood "A Beautiful Mind".

And in the lead, Fiennes engenders sympathy, despite little dialogue or obviously likeable behaviour.

However, despite or perhaps because of its veracity, the film is sometimes patience testing. The work of a literate, fiercely intelligent filmmaker - who describes it as having "the feel of Samuel Beckett confronting Sigmund Freud" - "Spider" is dour, thoughtful, and oppressive.

It's an experience that bores into your brain, but occasionally just bores.