There is no scientific evidence that psychiatric diagnoses such as schizophrenia and bipolar disorder are valid or useful, according to Britain's clinical psychologists.
In a groundbreaking move that has already prompted a fierce backlash from psychiatrists, the British Psychological Society's division of clinical psychology will issue a statement declaring that, given the lack of evidence, it is time for a "paradigm shift" in how the issues of mental health are understood.
The statement effectively casts doubt on psychiatry's predominantly biomedical model of mental distress – the idea that people are suffering from illnesses that are treatable by doctors using drugs.
Dr Lucy Johnstone, a consultant clinical psychologist who helped draw up the DCP's statement, said it was unhelpful to see mental health issues as illnesses with biological causes.
"On the contrary, there is now overwhelming evidence that people break down as a result of a complex mix of social and psychological circumstances..."