Can we prevent psychosis?
In a major study just published, Early detection and intervention evaluation for people at risk of psychosis, 288 young British adults who were deemed to be 'at risk of psychosis' were randomized to get cognitive therapy (CT) or a control condition. The hope was that it could prevent transition to serious psychotic illness.
The primary outcome measure was how many of them later went on to get diagnosed with full-blown psychosis. 2 years later, 7% of the CT group and 9% of the controls had, so that's no significant benefit of treatment. CT slightly reduced the level of mild psychotic-like symptoms, but not how much distress they caused.
So, in other words, no we can't prevent psychosis, not with CT alone at any rate. But there's lots more interesting stuff here...
Now a transition rate of some 8% over 2 years is lower than in previous studies and might suggest that the concept of the 'psychosis risk syndrome' or 'at-risk mental state' (under consideration for inclusion in DSM-5) is a bit dodgy. The venerable Prof. Allen Frances thinks so. But he misses the fact that the rate was 18% when you also count the people who went psychotic during the baseline assessments (to be fair to Frances, the authors buried that bombshell quite deep in the Discussion).
Still, that's still 82% false positives. Is that too high?
We can't tell, from a study like this. As in any disease screening program, we need to know the relative costs and benefits of true and false 'hits', as well as the percentages of them.
Here's some food for thought on that note. One of the key tenets of the CT model of psychosis is that 'psychotic' symptoms are a more or less normal response to stress, and that psychosis is maintained by a cycle of thoughts and feelings in which these experiences are themselves a source of concern, because they're felt to be abnormal, pathological, or otherwise threatening, thus leading to more stress, and more symptoms, and hence more concern... and so on. CT aims to break that cycle.
Check it out (image from here, coauthored by Graham Dunn, senior author of the present work.)
If you accept that, then it seems that literally the worst possible thing you could say to someone in the 'at risk mental state' is "Watch out! You're at risk of going psychotic!"According to CT, exactly that line of thinking is the root of the whole problem.
The authors of this paper indeed write that "Key ingredients of the approach [include] a focus on normalising psychotic-like experience". But who deemed them abnormal in the first place? The patient, all by themselves... or some well-meaning professional? It's not clear.
We are told that the patients were "seeking help for symptoms", but why? Of their own accord, or after someone else raised concerns? 45 people were referred to the study but excluded because they said that they didn't want help. So there was at least some degree of professional 'railroading', driven by the idea that people with such symptoms ought to seek help
If you accept the CT account of psychosis, then I'd say you ought to think very seriously about whether this whole thing isn't equivalent to giving everyone an X-ray to detect cancers. The X-rays might end up causing more tumours than they find.
I wonder if the authors of this study considered this.
Anyway. Keith Laws of LawsNeuroBlog has a good post about the study and the rather overexcited way it's been received in the press (even, er, the BMJ...)
Despite the authors not being able to make any claims about CT positively affecting transition rates... and the lack of any medication analysis (in fact all patients were unmedicated as an entry requirement) they conclude:
"On the basis of low transition rates, high responsiveness to simple interventions such as monitoring, a specific effect of cognitive therapy on the severity of psychotic symptoms, and the toxicity associated with antipsychotic drugs, we would suggest that antipsychotics are not delivered as a first line treatment to people meeting the criteria for being in an at risk mental state"
So the article in the UK Guardian entitledDrugs not best option for people at risk of psychosis, study warns
is not simply misunderstanding by a journalist, but what looks like author spinning....
The BMJ press release itself is headlinedCognitive therapy helps reduce severity of distress among psychotic patients- even though the paper (and the press release itself!) clearly states:
"Cognitive therapy did not significantly affect distress related to these psychotic experiences...nor levels of depression, social anxiety, or satisfaction with life..."
Morrison, A., French, P., Stewart, S., Birchwood, M., Fowler, D., Gumley, A., Jones, P., Bentall, R., Lewis, S., Murray, G., Patterson, P., Brunet, K., Conroy, J., Parker, S., Reilly, T., Byrne, R., Davies, L., and Dunn, G. (2012). Early detection and intervention evaluation for people at risk of psychosis: multisite randomised controlled trial BMJ, 344 (apr05 1) DOI: 10.1136/bmj.e2233
