Cognitive Models of Positive and Negative Symptoms of Schizophrenia and Implications for Treatment

This article reviews cognitive models of positive and negative symptoms of schizophrenia, as well as basic principles of cognitive behavioural therapy (CBT) for hallucinations, delusions and negative symptoms. Cognitive models of schizophrenia posit that individuals' view of the self is influenced by a combination of genetic vulnerability, early childhood experience and environmental stressors later in the life, and that these factors determine how internal and external experiences are interpreted. Cognitive behavioural therapy for schizophrenia is based on the basic principles of CBT and establishes connection between thoughts, emotions and behaviour. Treatment focuses on the meaning the individual attributes to psychotic experience, his or her understanding of it and ways of coping with symptoms, and is intended to reduce the distress caused by psychotic experience and correct thoughts and assumptions that are incompatible with objective evidence. The latest contradictory data on the efficacy of CBT for schizophrenia point to the need to use protocols that are tailored to specific symptoms and subgroups of patients based on the stage of illness, level of neurocognitive impairment and severity of the disorder, and manual-based in order to ensure fidelity of implementation.