I hear voices, along with approximately 3 per cent of the population. Yet only one in three becomes a psychiatric patient. Although hearing voices in itself is not necessarily a symptom of a mental illness, there is an 80 per cent chance of being labelled with schizophrenia if one goes to a psychiatrist claiming to do so.

The experience of hearing voices is much like a wide-awake dream. Dr Rufus May believes voices hold the key to healing unresolved emotions and that medications merely silence people outside of the norm.

In this extraordinary film, we see May enter into a dialogue with the voice that his patient, Ruth, hears. At times, both have doubts about his methods. He has resentment at his own psychiatric treatment when he was labelled with schizophrenia at the age of 18 – and justifiably so. Even in this modern age, psychiatry is brutal. For her part, Ruth Wilson is so credible in the part of Ruth that the re-enactment of their meetings struck me as joltingly truthful; as an actual sufferer, I feared for her safety.

I fully agree that we as a society should rethink our attitude towards voice-hearing. It is astonishing that psychiatric patients are not asked what the voices are like or what they say. But I believe there is a place for treatment with medicines when a person suffers hallucinations that cause such despair it is, as one sufferer described it, like being in a “constant state of mental rape”. It would be reckless not to acknowledge that.

Editor's choice

• The 100 Best Films of 2009
• The 100 Worst Movies of 2009
• The 100 Best Films of the Decade