This is a readable booklet marshalling current psychological thinking on psychosis, produced by a working party set up by the British Psychological Society, including several of the most renowned professors of clinical psychology in Britain today.

It will be found provocative by psychiatrists, because it constantly strives to drive a distinction between the way psychologists conceive of psychosis and the perspective of doctors.

Psychiatric propositions about biological causes are critically assessed, for example the dopamine hypothesis is dismissed as relying too heavily on arguments about dopamine-influencing medication, which the booklet asserts is like arguing that headaches are caused by lack of aspirin.

It tries instead to emphasise a dimensional rather than categorical or medical model approach to psychosis.

While the booklet rigorously and scientifically argues its case for a more psychological perspective, the key issue is what proportion of people with psychosis treated in the health service would really benefit from its recommendations. For example, would the kind of person admitted to an adult acute ward really benefit from more cognitive behavioural therapy and less medication and coercion, as opposed to the kind of person normally referred to a psychologist in an outpatient department?

It is difficult to escape the sense that this report has been put together by a group of well-meaning academics, who do not on a daily basis have to manage schizophrenia, or take decisions with profound legal implications, as clinical psychiatrists must.

Indeed the true empirical test begging to be instituted following this comprehensive report, would be for a group of daring psychologists to set up an acute ward and community service based solely on these psychological principles. This would help us all to see how far one can really take this kind of psychological model in the real world.