There has been much heated debate in recent weeks about whether cognitive behavioural therapy for psychosis has been totally over-egged. One stance is that Nice (the National Institute for Clinical Excellence) has recommended a treatment with little or no evidence base. Another is that CBT is a helpful intervention for many people experiencing psychotic-like phenomena.
But what is CBT for psychosis? What does it look like? And how can knowing this help us to understand the issues being argued about?
Psychosis is an umbrella term for a collection of symptoms. These symptoms get classed as “positive” or “negative”, which is not to infer that some are good and some are bad, but rather to capture the fact that some of the symptoms add something new and others take something away. Positive symptoms are those that add an unusual experience of some kind, eg seeing things that others can’t (hallucinations) or strongly believing things that don’t make sense to others (delusions). Negative symptoms involve something being taken away from the person, eg a lack of enjoyment (anhedonia), motivation (avolition), or a lack of emotion.
Whilst a recent meta-analysis has shown only limited evidence for the effectiveness of CBT for psychosis and suggested that previous results are inflated, we should be cautious about using this one meta-analysis to chuck out CBT for psychosis. Among other potential holes that could be poked in its conclusions is the fact that the analysis uses psychotic symptoms as the only outcome measure for effectiveness, which might not be the best or only thing we should be looking at.