We welcome Dr Marlowe's comments on our paper and would like to respond to the issues that he identified. The Cochrane review to which he refers examined more traditional approaches to early intervention (i.e. from first episode onwards) rather than a preventive approach in people at high risk, so we are unsure of the relevance of this. Within the manuscript we clearly acknowledge that there were several methodological limitations, including the exclusion of two participants, but we were unable to incorporate these in the abstract as he suggests because of limitations of abstract length imposed by the Journal (indeed, we were asked to further reduce the abstract at proof stage).

We agree that cognitive therapy for psychosis (and the prevention of psychosis) has an aim of decreasing the distress of psychotic experiences as well as the formulation of an explanatory model for a person's difficulties. We also agree that a reframed and normalised explanatory language may be developed by the service users; however, it is unlikely that this would lead to a masking of a psychotic episode. Rather, it is intended to reduce the potential for catastrophic appraisals of psychotic experiences, which are very clearly implicated in the experience of distress (Reference Chadwick and BirchwoodChadwick & Birchwood, 1994), and the development of normalising appraisals is at the heart of cognitive therapy for established psychosis (Reference Morrison, Renton and DunnMorrison et al, 2003) and the prevention of psychosis alike (Reference French and MorrisonFrench & Morrison, 2004). Even if such a masking were to occur, the assumption that this could cause harm clearly demonstrates a bias against the use of psychosocial interventions, as it suggests that only pharmacological treatments can reduce the potential harm that may result from an untreated psychotic episode, when there is evidence that psychological treatment is also important in this respect (Reference de Haan, Linszen and Leniorde Haan et al, 2003).

We are accused of being biased against using antipsychotic medication; we certainly are against medication in a population who are yet to develop a psychotic disorder, for the ethical reasons outlined within our paper and elsewhere (Reference Bentall and MorrisonBentall & Morrison, 2002). Finally, it is suggested that we avoid explicitly stating the possibility of harm arising from such an intervention; however, we clearly highlight the possibility of harm resulting from stigmatisation.