Aims – It used to be thought that the problems of psychosis were qualitatively difference from those of other disorders and therefore unamenable to psychological interventions. However more recent evidence will be summarised which suggests otherwise. Methods – A cognitive model of the positive symptoms of psychosis (Garety et al, 2001; Kuipers et al.,2006) is described which builds on work on the dimensions of symptoms of psychosis, the continuum between non-clinical and clinical populations, and the contribution of emotional processes, cognitive reasoning biases and social factors. Results – Evidence from both epidemiological and empirical studies from our research group and others, support some of the pathways of symptom formation and maintenance proposed by the model. Specifically there is evidence for the role of trauma, social adversity and stress. These may trigger emotional responses and unusual experiences and together with reasoning biases lead to appraisals that can be defined as positive symptoms such as delusions and hallucinations. Similar processes interact to maintain symptoms. Conclusions – Cognitive models of psychosis have led to the development of cognitive behavioural treatments for delusions and hallucinations, which show some evidence of efficacy. Such treatments need to be refined in the light of recent research.
Declaration of Interest: none